RESUMEN
Serotonergic neurons of the median raphe nucleus (MnR) and hypothalamic melanin-concentrating hormone (MCH)-containing neurons, have been involved in the control of REM sleep and mood. In the present study, we examined in rats and cats the anatomical relationship between MCH-containing fibers and MnR neurons, as well as the presence of MCHergic receptors in these neurons. In addition, by means of in vivo unit recording in urethane anesthetized rats, we determined the effects of MCH in MnR neuronal firing. Our results showed that MCH-containing fibers were present in the central and paracentral regions of the MnR. MCHergic fibers were in close apposition to serotonergic and non-serotonergic neurons. By means of an indirect approach, we also analyzed the presence of MCHergic receptors within the MnR. Accordingly, we microinjected MCH conjugated with the fluorophore rhodamine (R-MCH) into the lateral ventricle. R-MCH was internalized into serotonergic and non-serotonergic MnR neurons; some of these neurons were GABAergic. Furthermore, we determined that intracerebroventricular administration of MCH induced a significant decrease in the firing rate of 53 % of MnR neurons, while the juxtacellular administration of MCH reduced the frequency of discharge in 67 % of these neurons. Finally, the juxtacellular administration of the MCH-receptor antagonist ATC-0175 produced an increase in the firing rate in 78 % of MnR neurons. Hence, MCH produces a strong regulation of MnR neuronal activity. We hypothesize that MCHergic modulation of the MnR neuronal activity may be involved in the promotion of REM sleep and in the pathophysiology of depressive disorders.
Asunto(s)
Hormonas Hipotalámicas/farmacología , Hipotálamo/efectos de los fármacos , Melaninas/farmacología , Fibras Nerviosas/efectos de los fármacos , Neuronas/efectos de los fármacos , Hormonas Hipofisarias/farmacología , Núcleos del Rafe/efectos de los fármacos , Receptores de la Hormona Hipofisaria/metabolismo , Animales , Gatos , Hipotálamo/metabolismo , Hipotálamo/fisiología , Fibras Nerviosas/metabolismo , Fibras Nerviosas/fisiología , Neuronas/metabolismo , Neuronas/fisiología , Núcleos del Rafe/metabolismo , Núcleos del Rafe/fisiología , Ratas , Ratas WistarRESUMEN
PURPOSE: To determine interocular differences in Bruch's membrane opening minimum rim width (BMO-MRW) and retinal nerve fiber layer thickness (RNFLT) in healthy Brazilian individuals. MATERIALS AND METHODS: Both eyes of 220 healthy individuals were included in this observational, cross-sectional study. All individuals had normal clinical examination and visual fields. Global and sectorial interocular BMO-MRW and RNFLT differences, acquired and regionalized relative to the fovea to BMO center (FoBMO) axis, were calculated. The effect of age, axial length, and BMO area asymmetry on the parameters' asymmetry was evaluated. RESULTS: The 95th limits for interocular BMO-MRW and RNFLT global differences were 49 and 9 µm, respectively. BMO-MRW asymmetry was negatively correlated (ß=-33.87 µm/mm, R=0.06, P<0.001), whereas RNFLT asymmetry was positively correlated (ß= 6.13 µm/mm, R=0.09, P<0.001) with BMO area asymmetry. Neither BMO-MRW nor RNFLT asymmetries were correlated with axial length asymmetry (ß=-16.90 µm/mm, R=0.00, P=0.15; ß=-1.18 µm/mm, R=0.00, P=0.52, respectively). Similarly, BMO-MRW and RNFLT asymmetries were not correlated with age (ß=0.17 µm/y, R=0.01, P=0.22; ß=0.0 µm/y, R=0.00, P=0.19, respectively). CONCLUSIONS: Our results suggest that global BMO-MRW and RNFLT interocular differences exceeding 49 and 9 µm, respectively, may indicate statistically abnormal asymmetry, which may suggest early structural damage. Asymmetry in BMO area should be accounted for when considering interocular asymmetry in BMO-MRW and RNFLT.
Asunto(s)
Lámina Basal de la Coroides/anatomía & histología , Fibras Nerviosas/fisiología , Disco Óptico/anatomía & histología , Células Ganglionares de la Retina/citología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biometría , Brasil , Lámina Basal de la Coroides/diagnóstico por imagen , Estudios Transversales , Femenino , Voluntarios Sanos , Humanos , Presión Intraocular/fisiología , Masculino , Persona de Mediana Edad , Disco Óptico/diagnóstico por imagen , Estudios Prospectivos , Tomografía de Coherencia Óptica/métodos , Campos Visuales/fisiología , Adulto JovenRESUMEN
The neuromuscular effect of venoms is not a major clinical manifestation shared between rattlesnakes native to the Americas, which showed two different venom phenotypes. Taking into account this dichotomy, nerve muscle preparations from mice and chicks were used to investigate the ability of Crotalus atrox venom to induce in vitro neurotoxicity and myotoxicity. Unlike crotalic venoms of South America, low concentrations of C. atrox venom did not result in significant effects on mouse neuromuscular preparations. The venom was more active on avian nerve-muscle, showing reduction of twitch heights after 120â¯min of incubation with 10, 30 and 100⯵g/mL of venom with diminished responses to agonists and KCl. Histological analysis highlighted that C. atrox was myotoxic in both species of experimental animals; as evidenced by degenerative events, including edematous cells, delta lesions, hypercontracted fibers and muscle necrosis, which can lead to neurotoxic action. These results provide key insights into the myotoxicity and low neurotoxicity of C. atrox in two animal models, corroborating with previous genomic and proteomic findings and would be useful for a deeper understanding of venom evolution in snakes belonging to the genus Crotalus.
Asunto(s)
Venenos de Crotálidos/farmacología , Crotalus/fisiología , Músculo Esquelético/efectos de los fármacos , Fibras Nerviosas/efectos de los fármacos , Bloqueantes Neuromusculares/farmacología , Unión Neuromuscular/efectos de los fármacos , Animales , Pollos , Crotalus/crecimiento & desarrollo , Diafragma/citología , Diafragma/efectos de los fármacos , Diafragma/inervación , Diafragma/fisiología , Resistencia a Medicamentos , Técnicas In Vitro , Masculino , Ratones , Contracción Muscular/efectos de los fármacos , Músculo Esquelético/citología , Músculo Esquelético/inervación , Músculo Esquelético/fisiología , Fibras Nerviosas/fisiología , Unión Neuromuscular/fisiología , América del Norte , Especificidad de Órganos , Músculos Paraespinales/citología , Músculos Paraespinales/efectos de los fármacos , Músculos Paraespinales/inervación , Músculos Paraespinales/fisiología , Nervio Frénico/citología , Nervio Frénico/efectos de los fármacos , Nervio Frénico/fisiología , Especificidad de la Especie , Nervios Espinales/citología , Nervios Espinales/efectos de los fármacos , Nervios Espinales/fisiologíaRESUMEN
The simpler nervous systems of certain invertebrates provide opportunities to examine colocalized classical neurotransmitters in the context of identified neurons and well defined neural circuits. This study examined the distribution of γ-aminobutyric acid-like immunoreactivity (GABAli) in the nervous system of the panpulmonates Biomphalaria glabrata and Biomphalaria alexandrina, major intermediate hosts for intestinal schistosomiasis. GABAli neurons were localized in the cerebral, pedal, and buccal ganglia of each species. With the exception of a projection to the base of the tentacle, GABAli fibers were confined to the CNS. As GABAli was previously reported to be colocalized with markers for dopamine (DA) in five neurons in the feeding network of the euopisthobranch gastropod Aplysia californica (Díaz-Ríos, Oyola, & Miller, 2002), double-labeling protocols were used to compare the distribution of GABAli with tyrosine hydroxylase immunoreactivity (THli). As in Aplysia, GABAli-THli colocalization was limited to five neurons, all of which were located in the buccal ganglion. Five GABAli-THli cells were also observed in the buccal ganglia of two other intensively studied panpulmonate species, Lymnaea stagnalis and Helisoma trivolvis. These findings indicate that colocalization of the classical neurotransmitters GABA and DA in feeding central pattern generator (CPG) interneurons preceded the divergence of euopisthobranch and panpulmonate taxa. These observations also support the hypothesis that heterogastropod feeding CPG networks exhibit a common universal design.
Asunto(s)
Biomphalaria/metabolismo , Músculos/inervación , Músculos/fisiología , Tirosina 3-Monooxigenasa/metabolismo , Ácido gamma-Aminobutírico/metabolismo , Animales , Generadores de Patrones Centrales/fisiología , Extremidades/inervación , Extremidades/fisiología , Conducta Alimentaria , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/fisiología , Inmunohistoquímica , Interneuronas/fisiología , Lymnaea , Músculos/metabolismo , Fibras Nerviosas/fisiología , Neuronas/fisiología , Especificidad de la EspecieRESUMEN
The medullary dorsal horn (MDH or Sp5c/C1 region) plays a key role modulating the nociceptive input arriving from craniofacial structures. Some reports suggest that oxytocin could play a role modulating the nociceptive input at the MDH level, but no study has properly tested this hypothesis. Using an electrophysiological and pharmacological approach, the present study aimed to determine the effect of oxytocin on the nociceptive signaling in the MDH and the receptor involved. In sevoflurane, anesthetized rats, we performed electrophysiological unitary recordings of second order neurons at the MDH region responding to peripheral nociceptive-evoked responses of the first branch (V1; ophthalmic) of the trigeminal nerve. Under this condition, we constructed dose-response curves analyzing the effect of local spinal oxytocin (0.2-20 nmol) on MDH nociceptive neuronal firing. Furthermore, we tested the role of oxytocin receptors (OTR) or vasopressin V1A receptors (V1AR) involved in the oxytocin effects. Oxytocin dose-dependently inhibits the peripheral-evoked activity in nociceptive MDH neurotransmission. This inhibition is associated with a blockade of neuronal activity of Aδ- and C-fibers. Since this antinociception was abolished by pretreatment (in the MDH) with the potent and selective OTR antagonist (L-368,899; 20 nmol) and remained unaffected after the V1AR antagonist (SR49059; 20 nmol or 200 nmol), the role of OTR is implied. This electrophysiological study demonstrates that oxytocin inhibits the peripheral-evoked neuronal activity at MDH, through OTR activation. Thus, OTR may represent a new potential drug target to treat craniofacial nociceptive dysfunction in the MDH.
Asunto(s)
Nociceptores/efectos de los fármacos , Oxitócicos/farmacología , Oxitocina/farmacología , Receptores de Oxitocina/metabolismo , Receptores de Vasopresinas/metabolismo , Asta Dorsal de la Médula Espinal/citología , Potenciales de Acción/efectos de los fármacos , Análisis de Varianza , Animales , Antagonistas de los Receptores de Hormonas Antidiuréticas/farmacología , Canfanos/farmacología , Relación Dosis-Respuesta a Droga , Estimulación Eléctrica , Indoles/farmacología , Masculino , Fibras Nerviosas/fisiología , Oxitocina/antagonistas & inhibidores , Piperazinas/farmacología , Pirrolidinas/farmacología , Ratas , Ratas WistarRESUMEN
Small fibres in the skin are vulnerable to damage in metabolic or toxic conditions such as diabetes mellitus or chemotherapy resulting in small fibre neuropathy and associated neuropathic pain. Whether injury to the most distal portion of sensory small fibres due to a primary dermatological disorder can cause neuropathic pain is still unclear. Recessive dystrophic epidermolysis bullosa (RDEB) is a rare condition in which mutations of proteins of the dermo-epidermal junction lead to cycles of blistering followed by regeneration of the skin. Damage is exclusive to the skin and mucous membranes, with no known direct compromise of the nervous system. It is increasingly recognized that most RDEB patients experience daily pain, the aetiology of which is unclear but may include inflammation (in the wounds), musculoskeletal (due to atrophy and retraction scars limiting movement) or neuropathic pain. In this study we investigated the incidence of neuropathic pain and examined the presence of nerve dysfunction in RDEB patients. Around three quarters of patients presented with pain of neuropathic characteristics, which had a length-dependent distribution. Quantitative sensory testing of the foot revealed striking impairments in thermal detection thresholds combined with an increased mechanical pain sensitivity and wind up ratio (temporal summation of noxious mechanical stimuli). Nerve conduction studies showed normal large fibre sensory and motor nerve conduction; however, skin biopsy showed a significant decrease in intraepidermal nerve fibre density. Autonomic nervous system testing revealed no abnormalities in heart rate and blood pressure variability however the sympathetic skin response of the foot was impaired and sweat gland innervation was reduced. We conclude that chronic cutaneous injury can lead to injury and dysfunction of the most distal part of small sensory fibres in a length-dependent distribution resulting in disabling neuropathic pain. These findings also support the use of neuropathic pain screening tools in these patients and treatment algorithms designed to target neuropathic pain.
Asunto(s)
Epidermólisis Ampollosa Distrófica/fisiopatología , Hiperalgesia/fisiopatología , Neuralgia/etiología , Neuropatía de Fibras Pequeñas/fisiopatología , Adulto , Presión Sanguínea/fisiología , Estudios de Casos y Controles , Chile/epidemiología , Epidermólisis Ampollosa Distrófica/complicaciones , Epidermólisis Ampollosa Distrófica/patología , Femenino , Respuesta Galvánica de la Piel/fisiología , Frecuencia Cardíaca , Humanos , Hiperalgesia/complicaciones , Incidencia , Masculino , Fibras Nerviosas/patología , Fibras Nerviosas/fisiología , Conducción Nerviosa/fisiología , Neuralgia/complicaciones , Neuralgia/epidemiología , Umbral Sensorial , Piel/patología , Piel/fisiopatología , Neuropatía de Fibras Pequeñas/complicaciones , Neuropatía de Fibras Pequeñas/patología , Maniobra de Valsalva/fisiología , Adulto JovenRESUMEN
Although the release of mesoaccumbal dopamine is certainly involved in rewarding responses, recent studies point to the importance of the interaction between it and glutamate. One important component of this network is the anterior nucleus accumbens shell (aNAcSh), which sends GABAergic projections into the lateral hypothalamus (LH) and receives extensive glutamatergic inputs from, among others, the medial prefrontal cortex (mPFC). The effects of glutamatergic activation of aNAcSh on the ingestion of rewarding stimuli as well as its effect in the LH and mPFC are not well understood. Therefore, we studied behaving mice that express a light-gated channel (ChR2) in glutamatergic fibers in their aNAcSh while recording from neurons in the aNAcSh, or mPFC or LH. In Thy1-ChR2, but not wild-type, mice activation of aNAcSh fibers transiently stopped the mice licking for sucrose or an empty sipper. Stimulation of aNAcSh fibers both activated and inhibited single-unit responses aNAcSh, mPFC, and LH, in a manner that maintains firing rate homeostasis. One population of licking-inhibited pMSNs in the aNAcSh was also activated by optical stimulation, suggesting their relevance in the cessation of feeding. A rewarding aspect of stimulation of glutamatergic inputs was found when the Thy1-ChR2 mice learned to nose-poke to self-stimulate these inputs, indicating that bulky stimulation of these fibers are rewarding in the sense of wanting. Stimulation of excitatory afferents evoked both monosynaptic and polysynaptic responses distributed in the three recorded areas. In summary, we found that activation of glutamatergic aNAcSh fibers is both rewarding and transiently inhibits feeding. SIGNIFICANCE STATEMENT: We have established that the activation of glutamatergic fibers in the anterior nucleus accumbens shell (aNAcSh) transiently stops feeding and yet, because mice self-stimulate, is rewarding in the sense of wanting. Moreover, we have characterized single-unit responses of distributed components of a hedonic network (comprising the aNAcSh, medial prefrontal cortex, and lateral hypothalamus) recruited by activation of glutamatergic aNAcSh afferents that are involved in encoding a positive valence signal important for the wanting of a reward and that transiently stops ongoing consummatory actions, such as licking.
Asunto(s)
Conducta Alimentaria/fisiología , Glutamatos/fisiología , Área Hipotalámica Lateral/fisiología , Fibras Nerviosas/fisiología , Núcleo Accumbens/citología , Núcleo Accumbens/fisiología , Corteza Prefrontal/fisiología , Recompensa , Animales , Channelrhodopsins , Femenino , Masculino , Ratones , Neuronas Aferentes/fisiología , Optogenética , Técnicas de Placa-Clamp , Autoestimulación , Sinapsis/fisiologíaRESUMEN
The regenerative potential of the peripheral nervous system (PNS) is widely known, but functional recovery, particularly in humans, is seldom complete. Therefore, it is necessary to resort to strategies that induce or potentiate the PNS regeneration. Our main objective was to test the effectiveness of Olfactory Ensheathing Cells (OEC) transplantation into a biodegradable conduit as a therapeutic strategy to improve the repair outcome after nerve injury. Sciatic nerve transection was performed in C57BL/6 mice; proximal and distal stumps of the nerve were sutured into the collagen conduit. Two groups were analyzed: DMEM (acellular grafts) and OEC (1×105/2µL). Locomotor function was assessed weekly by Sciatic Function Index (SFI) and Global Mobility Test (GMT). After eight weeks the sciatic nerve was dissected for morphological analysis. Our results showed that the OEC group exhibited many clusters of regenerated nerve fibers, a higher number of myelinated fibers and myelin area compared to DMEM group. The G-ratio analysis of the OEC group showed significantly more fibers on the most suitable sciatic nerve G-ratio index. Motor recovery was accelerated in the OEC group. These data provide evidence that the OEC therapy can improve sciatic nerve functional and morphological recovery and can be potentially translated to the clinical setting.
Asunto(s)
Vaina de Mielina/trasplante , Regeneración Nerviosa/fisiología , Neuroglía/fisiología , Animales , Trasplante de Células , Ratones , Ratones Endogámicos C57BL , Vaina de Mielina/fisiología , Fibras Nerviosas/fisiología , Corteza Olfatoria , Recuperación de la Función/fisiología , Células de Schwann/trasplante , Nervio Ciático/lesionesRESUMEN
Carpal tunnel síndrome (CTS) is an entrapment neuropathy of the median nerve at the wrist, that leads to pain, paresthesia and painful dysesthesia. The electrophysiological diagnosis is based upon nerve conduction studies which evaluate thick nerve fibers. Our hypothesis is that there is an additional dysfunction of small fibers in CTS, which correlates with the degree of severity of the neuropathy. A retrospective study of 69 hands that belonged to 47 patients of both sexes (mean age 53.8, years, range 22-87) was performed, and, as a control group, 21 hands which corresponded to the asymptomatic side of those patients were evaluated. Motor and sensory conduction studies, as well as F-waves were performed to classify the neuropathy according to the degree of severity. Cutaneous silent period (CSP) was elicited in all hands. Mean onset latencies and durations of CSP were evaluated. Mean onset latencies were significantly prolonged in neuropathic hands (84.3 ± 16.3 msec) compared to asymptomatic hands (74.8 ± 11.6 msec) (p < 0.05). Mean latencies of the CSP were even prolonged (p < 0.05) in hands affected by a more severe neuropathy. In the 3 hands with most severe neuropathy, a CSP could not be elicited. In CTS an impairment of A-delta fibers was recorded through the CSP. The more severe the neuropathy is, the more impairment of A-delta fibers can be found. CSP may be assessed as a complement of motor and sensory nerve conduction studies in this neuropathy.
Asunto(s)
Síndrome del Túnel Carpiano/diagnóstico , Nervio Mediano , Fibras Nerviosas/fisiología , Adulto , Anciano de 80 o más Años , Análisis de Varianza , Síndrome del Túnel Carpiano/fisiopatología , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conducción Nerviosa/fisiología , Examen Neurológico/métodos , Periodo Refractario Electrofisiológico , Estudios Retrospectivos , Estadísticas no Paramétricas , Adulto JovenRESUMEN
El síndrome del túnel carpiano (STC) es una neuropatía por entrampamiento a nivel de la muñeca que cursa con dolor, parestesias y disestesias dolorosas. El diagnóstico electrofisiológico se basa en el estudio de la neuroconducción de las fibras gruesas. Nuestra hipótesis consiste en la existencia del compromiso de las fibras nerviosas finas y que este compromiso se correlaciona con el grado de gravedad. Se evaluaron retrospectivamente 69 manos correspondientes a 47 pacientes, varones y mujeres (edad media 53.8, rango 22-87 años) y como grupo contro, 21 manos correspondientes a los lados asintomáticos de estos casos. Se realizaron estudios de neuroconducción motora, sensitiva y ondas F para clasificar a las manos según el grado de gravedad. Se realizó el período silente cutáneo (PSC) en todas las manos. Se evaluaron latencias medias y duraciones medias del PSC. Las latencias medias se hallaron significativamente prolongadas en las manos con neuropatía (84.3 ± 16.3 mseg) con respecto a las manos sin neuropatía (74.8 ± 11.6 mseg), p < 0.05. Las latencias medias se hallaron más prolongadas en las manos con neuropatía de mayor gravedad (p < 0.05). En los 3 pacientes con neuropatía grado más grave no se halló el PSC. Se demostró el compromiso de las fibras finas A-delta en los pacientes con STC, con mayor compromiso a mayor severidad. El PSC puede usarse como complemento de los estudios de neuroconducción motora y sensitiva.
Carpal tunnel síndrome (CTS) is an entrapment neuropathy of the median nerve at the wrist, that leads to pain, paresthesia and painful dysesthesia. The electrophysiological diagnosis is based upon nerve conduction studies which evaluate thick nerve fibers. Our hypothesis is that there is an additional dysfunction of small fibers in CTS, which correlates with the degree of severity of the neuropathy. A retrospective study of 69 hands that belonged to 47 patients of both sexes (mean age 53.8, years, range 22-87) was performed, and, as a control group, 21 hands which corresponded to the asymptomatic side of those patients were evaluated. Motor and sensory conduction studies, as well as F-waves were performed to classify the neuropathy according to the degree of severity. Cutaneous silent period (CSP) was elicited in all hands. Mean onset latencies and durations of CSP were evaluated. Mean onset latencies were significantly prolonged in neuropathic hands (84.3 ± 16.3 msec) compared to asymptomatic hands (74.8 ± 11.6 msec) (p < 0.05). Mean latencies of the CSP were even prolonged (p < 0.05) in hands affected by a more severe neuropathy. In the 3 hands with most severe neuropathy, a CSP could not be elicited. In CTS an impairment of A-delta fibers was recorded through the CSP. The more severe the neuropathy is, the more impairment of A-delta fibers can be found. CSP may be assessed as a complement of motor and sensory nerve conduction studies in this neuropathy.
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Adulto Joven , Síndrome del Túnel Carpiano/diagnóstico , Nervio Mediano , Fibras Nerviosas/fisiología , Periodo Refractario Electrofisiológico , Síndrome del Túnel Carpiano/fisiopatología , Estudios de Casos y Controles , Estudios Retrospectivos , Análisis de Varianza , Estadísticas no Paramétricas , Conducción Nerviosa/fisiología , Examen Neurológico/métodosRESUMEN
PURPOSE: To assess cognitive performance differences among primary open-angle glaucoma (POAG) patients, normal-tension glaucoma (NTG) patients, and healthy control (C) subjects. METHODS: A total of 60 participants (20 POAG, 20 NTG, and 20 C subjects) were included in this study. A detailed ophthalmologic examination was performed on all participants. A spectral domain-optical coherence tomography (SD-OCT) system was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thicknesses. To assess the cognitive performance of all participants, detailed neurological examinations, including the mini-mental state examination (MMSE), were performed by the same neurologist. RESULTS: There were no significant differences among the groups in terms of age (p =0.348) or gender (p =0.935). The mean RNFL thicknesses were significantly different among the groups (85.2 ± 14.7, 76.8 ± 10.3, and 91.4 ± 7.7 µm in the POAG, NTG, and C subjects, respectively; p <0.001). The mean GC-IPL thicknesses were 77.5 ± 9.7 µm in the POAG group, 73.4 ± 7.8 µm in the NTG group, and 78.8 ± 3.8 µm in the C group. Differences among the groups were not statistically significant (p =0.085). MMSE scores were 26.1 ± 1.4, 25.7 ± 2.3, and 28.8 ± 0.9 in the POAG, NTG, and C groups, respectively. There were significant differences among the three groups (p <0.001). Specifically, there were significant differences between the NTG and C groups (p <0.001), and between the POAG and C groups (p =0.001). There was no significant difference between the POAG and NTG groups (p =0.595). CONCLUSIONS: There appear to be similar risk factors in glaucoma and neurodegenerative disorders that cause deterioration in cognitive performance. Comparing the low MMSE scores of the POAG and NTG patients with the scores of healthy C participants supports our hypothesis. Consequently, it is recommended that a neurologist should also examine glaucoma patients.
Asunto(s)
Cognición , Glaucoma de Ángulo Abierto , Glaucoma de Baja Tensión , Escala del Estado Mental/estadística & datos numéricos , Adulto , Anciano , Estudios de Casos y Controles , Demencia/diagnóstico , Demencia/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fibras Nerviosas/fisiología , Retina/anatomía & histología , Retina/fisiopatología , Células Ganglionares de la Retina/fisiología , Tomografía de Coherencia Óptica/métodosRESUMEN
ABSTRACT Purpose: To assess cognitive performance differences among primary open-angle glaucoma (POAG) patients, normal-tension glaucoma (NTG) patients, and healthy control (C) subjects. Methods: A total of 60 participants (20 POAG, 20 NTG, and 20 C subjects) were included in this study. A detailed ophthalmologic examination was performed on all participants. A spectral domain-optical coherence tomography (SD-OCT) system was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thicknesses. To assess the cognitive performance of all participants, detailed neurological examinations, including the mini-mental state examination (MMSE), were performed by the same neurologist. Results: There were no significant differences among the groups in terms of age (p =0.348) or gender (p =0.935). The mean RNFL thicknesses were significantly different among the groups (85.2 ± 14.7, 76.8 ± 10.3, and 91.4 ± 7.7 µm in the POAG, NTG, and C subjects, respectively; p <0.001). The mean GC-IPL thicknesses were 77.5 ± 9.7 µm in the POAG group, 73.4 ± 7.8 µm in the NTG group, and 78.8 ± 3.8 µm in the C group. Differences among the groups were not statistically significant (p =0.085). MMSE scores were 26.1 ± 1.4, 25.7 ± 2.3, and 28.8 ± 0.9 in the POAG, NTG, and C groups, respectively. There were significant differences among the three groups (p <0.001). Specifically, there were significant differences between the NTG and C groups (p <0.001), and between the POAG and C groups (p =0.001). There was no significant difference between the POAG and NTG groups (p =0.595). Conclusions: There appear to be similar risk factors in glaucoma and neurodegenerative disorders that cause deterioration in cognitive performance. Comparing the low MMSE scores of the POAG and NTG patients with the scores of healthy C participants supports our hypothesis. Consequently, it is recommended that a neurologist should also examine glaucoma patients.
RESUMO Objetivos: Avaliar as diferenças de desempenho cognitivo entre pacientes com glaucoma primário de ângulo aberto (POAG), glaucoma de pressão normal (NTG) e controle de indivíduos saudáveis (C). Métodos: Um total de 60 pessoas (20 POAG, 20 NTG e 20 indivíduos saudáveis) foram incluídos neste estudo. Um exame oftalmológico detalhado foi realizado em todos os participantes. Um sistema de tomografia de coerência óptica de domínio espectral (SD-OCT) foi utilizado para medir as espessuras da camada de células ganglionares plexiforme interna (GC-IPL) e da camada de fibras nervosas da retina (RNFL). Para avaliar o desempenho cognitivo de todos os participantes, foi realizado pelo mesmo neurologista um exame neurológico detalhado, incluindo mini-exame do estado mental (MMSE). Resultados: Não houve diferenças significativas entre os grupos em termos de idade (p=0,348) e sexo (p=0,935). Espessuras médias da RNFL foram significativamente diferentes, sendo 85,2 ± 14,7, 76,8 ± 10,3 e 91,4 ± 7,7 µm nos grupos POAG, NTG e controles, respectivamente (p<0,001). As espessuras médias da GC-IPL observadas foram 77.5 ± 9.7 μm no grupo POAG, 73,4 ± 7,8 µm no grupo NTG e 78,8 ± 3,8 µm nos controlos. As diferenças entre os grupos não foram estatisticamente significantes (p=0,085). Graduações do MMSE foram 26,1 ± 1,4, 25,7 ± 2,3 e 28,8 ± 0,9 nos grupos POAG, NTG e controles, respectivamente. Houve diferenças significativas entre os três grupos (p<0,001). Houve diferença significativa entre NTG e saudáveis (p<0,001). Houve diferença significativa entre POAG e saudáveis (p=0,001). Não houve diferença significativa entre o POAG e NTG (p=0,595). Conclusões: Parecem haver fatores de risco semelhantes no glaucoma e nos distúrbios neurodegenerativos que causam deterioração no desempenho cognitivo. Comparando a baixa graduação do MMSE de pacientes com POAG e NTG com controles saudáveis referenda nossa hipótese. Consequentemente recomenda-se que um neurologista também examine os pacientes de glaucoma.
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Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Glaucoma de Ángulo Abierto , Cognición , Glaucoma de Baja Tensión , Escala del Estado Mental/estadística & datos numéricos , Retina/anatomía & histología , Retina/fisiopatología , Células Ganglionares de la Retina/fisiología , Estudios de Casos y Controles , Demencia/diagnóstico , Demencia/fisiopatología , Tomografía de Coherencia Óptica/métodos , Fibras Nerviosas/fisiologíaAsunto(s)
Humanos , Masculino , Femenino , Electromiografía , Fibras Nerviosas/patología , Fibras Nerviosas/fisiologíaRESUMEN
OBJECTIVE: To better define prelemniscal radiations (Raprl) as a target for the control of tremor and rigidity in Parkinson's disease (PD). METHODS: A total of 36 deep brain stimulation (DBS) electrodes were stereotactically implanted in Raprl contralateral to the extremities to be treated. Effects on symptoms were evaluated using UPDRS-III before and after DBS, and significance was determined using the Wilcoxon test. The location of DBS contacts in cases with optimum versus suboptimum results was evaluated using Student's t test and percentage improvement correlated through a bivariable Pearson test. The power and percentage of spike components for microelectrode recordings were statistically compared between the target point and structures located above and below. RESULTS: Raprl-DBS improved tremor and rigidity (p < 0.01). The potency of microelectrode recordings indicated that the target was formed by fibers. There was no correlation between demographic characteristics and clinical outcome, and there were no significant differences in stereotactic placement between cases with optimum and suboptimum results. Tremor and rigidity were selectively improved in cases with suboptimum results. CONCLUSION: Raprl-DBS is an effective treatment for the motor symptoms of PD. Selective improvement of symptoms suggests that the target has different fiber components related to either tremor or rigidity, and variations in improvement between cases may derive from individual variations of the location of these fibers.
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Estimulación Encefálica Profunda/métodos , Rigidez Muscular/terapia , Enfermedad de Parkinson/terapia , Subtálamo/fisiopatología , Temblor/terapia , Adulto , Anciano , Electrodos Implantados , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Microelectrodos , Persona de Mediana Edad , Rigidez Muscular/etiología , Rigidez Muscular/fisiopatología , Fibras Nerviosas/fisiología , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/fisiopatología , Técnicas Estereotáxicas , Subtálamo/patología , Resultado del Tratamiento , Temblor/etiología , Temblor/fisiopatología , Sustancia Blanca/patología , Sustancia Blanca/fisiopatologíaRESUMEN
Objective: Patients with Wilson’s disease (WD) may develop a wide variety of neuropsychiatric symptoms, but there are few reports of autonomic dysfunction. Here, we described evidence of small fiber and/or autonomic dysfunction in 4 patients with WD and levodopa-responsive parkinsonism. Method: We reviewed the charts of 4 patients with WD who underwent evaluation for the presence of neuromuscular dysfunction and water-induced skin wrinkling test (SWT). Results: Two men and 2 women (33±3.5 years) with WD were evaluated. They all had parkinsonism at some point during their disease course. Parkinsonism on patient 4 almost completely subsided with treatment of WD. Two patients had significant sensory and 2 significant autonomic complaints, including syncopal spells. NCS/EMG was normal in all but SWT was abnormal in half of them (mean 4-digit wrinkling of 0.25 and 1). Discussion: A subset of patients with WD exhibit evidence of abnormal skin wrinkling test (small fiber neuropathy). .
Objetivo: Pacientes com doença de Wilson (DW) podem desenvolver uma ampla variedade de sintomas neuropsiquiátricos, mas existem poucos relatos de disfunção autonômica. Aqui, nós descrevemos evidência de disfunção de fibras finas/autonômica em 4 pacientes com DW e parkinsonismo responsivo à levodopa. Método: Nós revisamos os prontuários de 4 pacientes com DW que foram submetidos a avaliação neuromuscular e ao teste de quantificação do enrugamento cutâneo (TEC). Resultados: Dois homens e 2 mulheres (33±3,5 anos) com DW foram avaliados. Todos apresentaram parkinsonismo durante o curso de sua doença. Parkinsonismo no paciente 4 quase completamente desapareceu com tratamento da DW. Dois pacientes apresentaram queixas sensitivas e 2 apresentaram queixas autonômicas significativas incluindo episódios de síncope. Eletroneuromiografia foi normal em todos e TEC foi anormal em metade deles (score do TEC nos 4 dedos de 0,25 e 1). Discussão: Um subgrupo de pacientes com DW apresenta evidência de TEC anormal (neuropatia de fibras finas). .
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Adulto , Femenino , Humanos , Masculino , Adulto Joven , Degeneración Hepatolenticular/fisiopatología , Fibras Nerviosas/fisiología , Conducción Nerviosa/fisiología , Nervios Periféricos/fisiopatología , ElectromiografíaRESUMEN
OBJECTIVE: Patients with Wilson's disease (WD) may develop a wide variety of neuropsychiatric symptoms, but there are few reports of autonomic dysfunction. Here, we described evidence of small fiber and/or autonomic dysfunction in 4 patients with WD and levodopa-responsive parkinsonism. METHOD: We reviewed the charts of 4 patients with WD who underwent evaluation for the presence of neuromuscular dysfunction and water-induced skin wrinkling test (SWT). RESULTS: Two men and 2 women (33±3.5 years) with WD were evaluated. They all had parkinsonism at some point during their disease course. Parkinsonism on patient 4 almost completely subsided with treatment of WD. Two patients had significant sensory and 2 significant autonomic complaints, including syncopal spells. NCS/EMG was normal in all but SWT was abnormal in half of them (mean 4-digit wrinkling of 0.25 and 1). DISCUSSION: A subset of patients with WD exhibit evidence of abnormal skin wrinkling test (small fiber neuropathy).
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Degeneración Hepatolenticular/fisiopatología , Fibras Nerviosas/fisiología , Conducción Nerviosa/fisiología , Nervios Periféricos/fisiopatología , Adulto , Electromiografía , Femenino , Humanos , Masculino , Adulto JovenRESUMEN
The purpose of the present study was to investigate the modulation of spontaneous afferent activity by ATP during embryonic development in a preparation isolated chicken inner ear. This work was performed using multiunit and single-unit extracellular recordings from the posterior semicircular canal nerve and the basilar papilla nerve. α,ß-meATP, a P2X receptor agonist, notably increased the discharge frequency of the vestibular afferents between E15 and E18, but not in the basilar papilla. In contrast, the P2Y receptor agonist UTP produced a slight increase in the discharge frequency of basilar papilla afferents, without apparent changes in the vestibular afferent activity. 2-MeSATP, a P2Y agonist, increased the basal discharge of the primary afferents in a dose-age dependent way, but when we applied the antagonist of P2Y receptor, Reactive Blue 2 (10(-4)M), the effect of 2-MeSATP decreased significantly. This was observed both in vestibule and basilar papilla. Using RT-PCR the presence of P2X3, P2Y1, P2Y2 and P2Y6 mRNA was documented in the vestibular system with more important presence during the early stage (E15) than the later stage (E21), however in the basilar papilla we found only the P2Y1, P2Y2 and P2Y6 mRNA with the same temporal course as in the vestibule. These results confirm our pharmacological findings. Together this data suggests a role for P2X receptors-mediated purinergic signaling in vestibular synaptic organization. Temporal changes in P2Y receptors during development might be involved in the establishment of the endolymphatic ion composition needed for normal vestibular and auditory transduction and/or specific cellular differentiation.
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Oído Interno/metabolismo , Receptores Purinérgicos P2X/metabolismo , Receptores Purinérgicos P2Y/metabolismo , Potenciales de Acción , Vías Aferentes/fisiología , Animales , Embrión de Pollo , Oído Interno/inervación , Fibras Nerviosas/fisiología , Órgano Espiral/metabolismo , Agonistas del Receptor Purinérgico P2X/farmacología , Agonistas del Receptor Purinérgico P2Y/farmacología , Vestíbulo del Laberinto/inervación , Vestíbulo del Laberinto/metabolismoRESUMEN
Recently it has been suggested that the neurohormone prolactin (PRL) could act on the afferent nociceptive neurons. Indeed, PRL sensitizes transient receptor potential vanilloid 1 (TRPV1) channels present in nociceptive C-fibers and consequently reduces the pain threshold in a model of inflammatory pain. Accordingly, high plasma PRL levels in non-lactating females have been associated with several painful conditions (e.g. migraine). Paradoxically, an increase of PRL secretion during lactation induced a reduction in pain sensitivity. This difference could be attributed to the fact that PRL secreted from the adenopituitary (AP) is transformed into several molecular variants by the suckling stimulation. In order to test this hypothesis, the present study set out to investigate whether PRL from AP of suckled (S) or non-suckled (NS) lactating rats affects the activity of the male Wistar wide dynamic range (WDR) neurons. The WDR neurons are located in the dorsal horn of the spinal cord and receive input from the first-order neurons (Ab-, Ad- and C-fibers). Spinal administration of prolactin variant from NS rats (NS-PRL) or prolactin variant from S rats (S-PRL) had no effect on the neuronal activity of non-nociceptive Ab-fibers. However, the activities of nociceptive Ad-fibers and C-fibers were: (i) increased by NS-PRL and (ii) diminished by S-PRL. Either NS-PRL or S-PRL enhanced the post-discharge activity. Taken together, these results suggest that PRL from S or NS lactating rats could either facilitate or depress the nociceptive responses of spinal dorsal horn cells, depending on the physiological state of the rats.
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Lactancia/fisiología , Fibras Nerviosas/efectos de los fármacos , Nociceptores/fisiología , Células del Asta Posterior/fisiología , Prolactina/farmacología , Médula Espinal/citología , Animales , Femenino , Lactancia/sangre , Masculino , Fibras Nerviosas/fisiología , Nociceptores/efectos de los fármacos , Umbral del Dolor/efectos de los fármacos , Umbral del Dolor/fisiología , Células del Asta Posterior/efectos de los fármacos , Prolactina/sangre , Ratas , Ratas WistarRESUMEN
PURPOSE: To evaluate the eye-tracking-based follow-up (EBF) function in the reproducibility of the peripapillary retinal nerve fiber layer (RNFL) thickness measurements obtained with Fourier-domain optical coherence tomography (Fd-OCT). METHODS: Thirty healthy subjects were imaged on an Fd-OCT device at the same visit by two examiners. Peripapillary circular scans in "high-speed" (HS) mode with the "automatic real time" (ART) set at 16 and in "high-resolution" (HR) mode with the ART off were obtained without and with the EBF function activated. RESULTS: Mean (± SD) global RNFL thickness was 105.1 (± 9.5) µm on HS mode and 105.4 (± 9.6) µm on HR mode. Interobserver analysis for global RNFL thickness revealed an intraclass correlation coefficient (ICC) greater than or equal to 0.96 for all but the HR mode without the use of EBF function (ICC = 0.73). Intraobserver analysis for global RNFL thickness revealed an ICC greater than 0.98 for all but the HR mode without the use of EBF function (ICC = 0.86). The interobserver and intraobserver analyses revealed the lowest ICC values for the temporal region on both HS and HR modes. Higher ICC values were obtained with the HS mode and when the EBF function was activated, particularly when using the HR mode. CONCLUSIONS: The EBF function had no influence in the reproducibility of the global peripapillary RNFL thickness measurements in healthy subjects on HS mode with ART on. However, reproducibility of the global RNFL thickness measurements on HR mode as well as of the temporal and temporal superior regions in both HS and HR modes was greater with the EBF function.
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Análisis de Fourier , Fibras Nerviosas/fisiología , Disco Óptico/patología , Células Ganglionares de la Retina/fisiología , Tomografía de Coherencia Óptica/métodos , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Disco Óptico/fisiopatología , Estudios Prospectivos , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
PURPOSE: To investigate the efficiency of electrical stimulation in the muscle maintenance and nerve regeneration after end-to-side neurorrhaphy (ESN). METHODS: Sixty male Wistar rats (Rattus norvegicus) were divided into four experimental groups. Control group (Control), Denervated Group (Denervated); Group with End-to-side neurorrhaphy (ESN); Group with End-to-side neurorrhaphy and electrical stimulation (ESN + ES). We perform electrical stimulation in rats after they had undergone muscle reinnervation by ESN. We collected morphometric and functional data. RESULTS: When comparing the mass of the treated side of cranial tibial muscle (CTM) and that of normal side of CTM, the group ESN + ES (26.12%) exhibited lower mass loss than that of group ESN (37.23%). The peroneal functional index showed that group ESN + ES equaled that of the Control group and showed an evolution of 60.5% while group ESN showed an evolution of 9.5%. In measuring maximum strength of CTM, the group ES + ESN outperformed group ESN. The muscle and nerve morphometry showed superiority of group ES+ESN over ESN group in all parameters. CONCLUSION: Electrical stimulation is an effective means of maintaining functional muscle and nerve regeneration after end-to-side neurorrhaphy.