RESUMEN

Limnological characteristics of the Violão and Amendoim lakes, in the Serra dos Carajás, Amazon, were studied interannually (2013-2014). Climate data indicate anomalous conditions during the 2013 rainy period with higher rainfall and lower temperature in the beginning (November). Lake levels were influenced after the first and second hour of each rainfall, which showed a strong synchronization between seasonal fluctuation of lake levels and local weather patterns. Based on the water quality, both lakes are classified as classes "1" and "2" in the CONAMA (Conselho Nacional do Meio Ambiente) scheme and as "excellent" to "good" in the WQI (Water Quality Index) categories. However, the limnology is distinctly different between the lakes and seasons. Higher trophic state and phytoplankton productivity were observed mainly during the rainy period in Violão Lake compared to Amendoim Lake. This may be due to deposition of leached nutrients in the former, mainly total phosphorus (TP), which was probably derived from mafic soils and guano. This is consistent with the significant positive correlation between Chlorophyll-a and TP at the end of the rainy period (March-April), whereas this was not observed in the beginning (November). This could possibly be a consequence of the more intense cloud cover, and unusual high rainfall that limits nutrient availability.

RESUMEN

Neuregulin1 (NRG1) is a single transmembrane protein that plays a critical role in neural development and synaptic plasticity. Both NRG1 and its receptor, ErbB4, are well-established risk genes of schizophrenia. The NRG1 ecto-domain (ED) binds and activates ErbB4 following proteolytic cleavage of pro-NRG1 precursor protein. Although several studies have addressed the function of NRG1 in brain, very little is known about the cleavage and shedding mechanism. Here we show that the neuronal vesicular protein calcyon is a potent activator and key determinant of NRG1 ED cleavage and shedding. Calcyon stimulates clathrin-mediated endocytosis and endosomal targeting; and its levels are elevated in postmortem brains of schizophrenics. Overexpression of calcyon stimulates NRG1 cleavage and signaling in vivo, and as a result, GABA transmission is enhanced in calcyon overexpressing mice. Conversely, NRG1 cleavage, ErbB4 activity and GABA transmission are decreased in calcyon null mice. Moreover, stimulation of NRG1 cleavage by calcyon was recapitulated in HEK 293 cells suggesting the mechanism involved is cell-autonomous. Finally, studies with site-specific mutants in calcyon and inhibitors for the major sheddases indicate that the stimulatory effects of calcyon on NRG1 cleavage and shedding depend on clathrin-mediated endocytosis, ß-secretase 1, and interaction with clathrin adaptor proteins. Together these results identify a novel mechanism for NRG1 cleavage and shedding.

Asunto(s)

Endosomas/metabolismo , Moduladores del GABA/metabolismo , Proteínas de la Membrana/metabolismo , Neurregulina-1/metabolismo , Secretasas de la Proteína Precursora del Amiloide/metabolismo , Animales , Ácido Aspártico Endopeptidasas/metabolismo , Técnicas de Cultivo de Célula , Endocitosis/fisiología , Células HEK293 , Hipocampo/metabolismo , Humanos , Proteínas de la Membrana/genética , Ratones , Ratones Noqueados , Neurregulina-1/genética , Plasticidad Neuronal , Receptor ErbB-4/metabolismo , Factores de Riesgo , Esquizofrenia/genética , Esquizofrenia/metabolismo , Transducción de Señal , Sinapsis/fisiología

RESUMEN

This study compares surface electromyographic activity of the internal oblique, rectus abdominis, multifidus, iliocostalis, anterior deltoids during the pull-up on a lower and on a higher difficulty level. We assessed nine adults with previous experience in Pilates. The root mean square (RMS) values were normalized by maximum isometric contraction for each participant. During the ascent phase, the low spring position showed a significantly higher RMS than the high spring position of 8.9% for deltoid, 17.2% for internal oblique, 22.3% for rectus abdominis, 4.1% for iliocostalis, and 5.6% for multifidus, and in the descent phase, the RMS in the lower spring exceeded significantly the high spring position in 1.6% for the deltoid, 10% for internal oblique, 31.4% for rectus abdominis and 11.4% for iliocostalis. There was no predominance of abdominal muscles over the shoulder muscle in any spring position. The pull-up exercise can be a useful choice for the core and anterior deltoid muscles strengthening...

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Este estudo compara a atividade eletromiográfica de superfície dos músculos oblíquo interno, reto abdominal, multífidos, iliocostal e deltóide anterior durante o pull-up em dois níveis de dificuldade (mola alta e mola baixa). Foram avaliadas nove adultos com experiência anterior em Pilates. Os valores RMS foram normalizados pela contração isométrica máxima. Durante a fase de subida, a posição de mola baixa mostrou RMS significativamente maiores em relação a alta de 8,9% para deltóide, 17,2% para o oblíquo interno, 22,3% para o reto abdominal, 4,1% para iliocostal, e 5,6% para o multífido, e na fase de descida, em 1,6% para o deltóide, 10% para oblíquo interno, 31,4% para o reto abdominal e 11,4% para o iliocostal. Não houve predomínio dos músculos abdominais sob o músculo do ombro em qualquer posição de mola. O exercício de pull-up pode ser ferramenta útil para o fortalecimento da musculatura do core e do músculo deltóide anterior...

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Este estudio compara la EMG superficial de los músculos recto del abdomen, oblicuo interno, multifidos, ilio-costal y deltoides anterior durante el ejercicio pull-up en dos niveles de dificultad. Se evaluaron a nueve adultos experimentados en Pilates. Los valores de RMS se normalizaron por la contracción isométrica máxima. Durante la fase de ascenso, la posición baja del resorte mostró valores significativamente majores de RMS que la posición alta de 8,9% para lo deltoides, 17,2% para oblicuo interno, 22,3% para recto abdominal, 4,1% para ilio-costalis, y 5,6% para multifidos. En la fase de descenso, el RMS, en el muelle inferior, excede significativamente la posición alta del resorte en 1,6% para el deltoides, 10% para oblicuo interno, 31,4% para recto abdominal y 11,4% para ilio-costalis. No hubo predominio de los músculos abdominales bajo los deltoides anteriores. Pull-up puede ser una herramienta útil para el trabajo del core y para la fortificación del deltoides anterior...

Asunto(s)

Humanos , Masculino , Femenino , Adulto , Terapia por Ejercicio , Músculos Abdominales/fisiología , Músculos Pectorales/fisiología , Electromiografía/métodos

RESUMEN

Calcyon regulates activity-dependent internalization of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) glutamate receptors and long-term depression of excitatory synapses. Elevated levels of calcyon are consistently observed in brains from schizophrenic patients, and the calcyon gene is associated with attention-deficit hyperactivity disorder. Executive function deficits are common to both disorders, and at least for schizophrenia, the etiology appears to involve both heritable and neurodevelopmental factors. Here, we show with calcyon-overexpressing Cal(OE) transgenic mice that lifelong calcyon upregulation impairs executive functions including response inhibition and working memory, without producing learning and memory deficits in general. As response inhibition and working memory, as well as the underlying neural circuitry, continue to mature into early adulthood, we functionally silenced the transgene during postnatal days 28-49, a period corresponding to adolescence. Remarkably, the response inhibition and working memory deficits including perseverative behavior were absent in adult Cal(OE) mice with the transgene silenced in adolescence. Suppressing the calcyon transgene in adulthood only partially rescued the deficits, suggesting calcyon upregulation in adolescence irreversibly alters development of neural circuits supporting mature response inhibition and working memory. Brain regional immunoblots revealed a prominent downregulation of AMPA GluR1 subunits in hippocampus and GluR2/3 subunits in hippocampus and prefrontal cortex of the Cal(OE) mice. Silencing the transgene in adolescence prevented the decrease in hippocampal GluR1, further implicating altered fronto-hippocampal connectivity in the executive function deficits observed in the Cal(OE) mice. Treatments that mitigate the effects of high levels of calcyon during adolescence could preempt adult deficits in executive functions in individuals at risk for serious mental illness.

Asunto(s)

Inhibición Psicológica , Proteínas de la Membrana/metabolismo , Trastornos de la Memoria/fisiopatología , Memoria a Corto Plazo/fisiología , Regulación hacia Arriba/fisiología , Animales , Animales Recién Nacidos , Quinasa de la Proteína Quinasa Dependiente de Calcio-Calmodulina/genética , Condicionamiento Psicológico/efectos de los fármacos , Condicionamiento Psicológico/fisiología , Modelos Animales de Enfermedad , Doxiciclina/metabolismo , Doxiciclina/farmacología , Extinción Psicológica/efectos de los fármacos , Extinción Psicológica/fisiología , Miedo/efectos de los fármacos , Miedo/fisiología , Humanos , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Proteínas de la Membrana/genética , Trastornos de la Memoria/genética , Ratones , Ratones Transgénicos , Receptores AMPA/metabolismo , Percepción Espacial/efectos de los fármacos , Percepción Espacial/fisiología , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética

RESUMEN

UNLABELLED: Queiroz BC, Cagliari MF, Amorim CF, Sacco IC. Muscle activation during four Pilates core stability exercises in quadruped position. OBJECTIVE: To compare the activity of stabilizing trunk and hip muscles in 4 variations of Pilates stabilizing exercises in the quadruped position. DESIGN: Repeated-measures descriptive study. SETTING: A biomechanics laboratory at a university school of medicine. PARTICIPANTS: Healthy subjects (N=19; mean age +/- SD, 31+/-5y; mean weight +/- SD, 60+/-11kg; mean height +/- SD, 166+/-9cm) experienced in Pilates routines. INTERVENTIONS: Surface electromyographic signals of iliocostalis, multifidus, gluteus maximus, rectus abdominis, and external and internal oblique muscles were recorded in 4 knee stretch exercises: retroverted pelvis with flexed trunk; anteverted pelvis with extended trunk; neutral pelvis with inclined trunk; and neutral pelvis with trunk parallel to the ground. MAIN OUTCOME MEASURES: Root mean square values of each muscle and exercise in both phases of hip extension and flexion, normalized by the maximal voluntary isometric contraction. RESULTS: The retroverted pelvis with flexed trunk position led to significantly increased external oblique and gluteus maximus muscle activation. The anteverted pelvis with trunk extension significantly increased multifidus muscle activity. The neutral pelvis position led to significantly lower activity of all muscles. Rectus abdominis muscle activation to maintain body posture was similar in all exercises and was not influenced by position of the pelvis and trunk. CONCLUSIONS: Variations in the pelvic and trunk positions in the knee stretch exercises change the activation pattern of the multifidus, gluteus maximus, rectus abdominis, and oblique muscles. The lower level of activation of the rectus abdominis muscle suggests that pelvic stability is maintained in the 4 exercise positions.

Asunto(s)

Técnicas de Ejercicio con Movimientos , Cadera/fisiología , Músculo Esquelético/fisiología , Músculos Abdominales/fisiología , Adulto , Fenómenos Biomecánicos , Electromiografía , Femenino , Humanos , Masculino

RESUMEN

The recently cloned protein, calcyon, potentiates crosstalk between G(s)-coupled dopamine D1 receptors and heterologous G(q/11)-coupled receptors allowing dopamine D1 receptors to stimulate intracellular Ca(2+) release, in addition to cAMP production. This crosstalk also requires the participating G(q/11)-coupled receptors to be primed by their agonists. We examined the ability of calcyon and priming to regulate the affinity of dopamine D1 receptors for its ligands. Receptor binding assays were performed on HEK293 cell membrane preparations expressing dopamine D1 receptors either alone or in combination with calcyon. Co-expression of dopamine D1 receptor and calcyon affected neither the affinity of this receptor for antagonists nor the affinity of agonist binding to this receptor high and low-affinity states. However, the presence of calcyon dramatically decreased the proportion of the high-affinity dopamine D1 receptor agonist binding sites. This decrease was reversed by carbachol, which primes the receptor crosstalk by stimulating endogenous G(q/11)-coupled muscarinic receptors. Our findings suggest that calcyon regulates the ability of dopamine D1 receptors to achieve the high-affinity state for agonists, in a manner that depends on priming of receptor crosstalk.

Asunto(s)

Proteínas de la Membrana/fisiología , Receptor Cross-Talk/fisiología , Receptores de Dopamina D1/metabolismo , Apomorfina/análogos & derivados , Apomorfina/metabolismo , Apomorfina/farmacología , Benzazepinas/metabolismo , Benzazepinas/farmacología , Unión Competitiva/efectos de los fármacos , Carbacol/farmacología , Línea Celular , Agonistas de Dopamina/metabolismo , Agonistas de Dopamina/farmacología , Antagonistas de Dopamina/metabolismo , Antagonistas de Dopamina/farmacología , Relación Dosis-Respuesta a Droga , Guanosina Trifosfato/farmacología , Humanos , Proteínas de la Membrana/genética , Ensayo de Unión Radioligante , Receptor Cross-Talk/efectos de los fármacos , Receptores de Dopamina D1/genética , Tritio

RESUMEN

The D(1) dopamine receptor, G protein gamma(7) subunit, and adenylylcyclase are selectively expressed in the striatum, suggesting their potential interaction in a common signaling pathway. To evaluate this possibility, a ribozyme strategy was used to suppress the expression of the G protein gamma(7) subunit in HEK 293 cells stably expressing the human D(1) dopamine receptor. Prior in vitro analysis revealed that the gamma(7) ribozyme possessed cleavage activity directed exclusively toward the gamma(7) RNA transcript (Wang, Q., Mullah, B., Hansen, C., Asundi, J., and Robishaw, J. D. (1997) J. Biol. Chem. 272, 26040-26048). In vivo analysis of cells transfected with the gamma(7) ribozyme showed a specific reduction in the expression of the gamma(7) protein. Coincident with the loss of the gamma(7) protein, there was a noticeable reduction in the expression of the beta(1) protein, confirming their interaction in these cells. Finally, functional analysis of ribozyme-mediated suppression of the beta(1) and gamma(7) proteins revealed a significant attenuation of SKF81297-stimulated adenylylcyclase activity in D(1) dopamine receptor-expressing cells. By contrast, ribozyme-mediated suppression of the beta(1) and gamma(7) proteins showed no reduction of SKF81297-stimulated adenylylcyclase activity in D(5) dopamine receptor-expressing cells. Taken together, these data indicate that the structurally related D(1) and D(5) dopamine receptor subtypes utilize G proteins composed of distinct betagamma subunits to stimulate adenylylcyclase in HEK 293 cells. Underscoring the physiological relevance of these findings, single cell reverse transcriptase-polymerase chain reaction analysis revealed that the D(1) dopamine receptor and the G protein gamma(7) subunit are coordinately expressed in substance P containing neurons in rat striatum, suggesting that the G protein gamma(7) subunit may be a new target for drugs to selectively alter dopaminergic signaling within the brain.

Asunto(s)

Adenilil Ciclasas/metabolismo , Proteínas de Unión al GTP/química , Proteínas de Unión al GTP/metabolismo , Receptores de Dopamina D1/metabolismo , Secuencia de Bases , Línea Celular , AMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Activación Enzimática , Humanos , Cinética , Datos de Secuencia Molecular , Neuronas/metabolismo , Reacción en Cadena de la Polimerasa , Unión Proteica , ARN Catalítico/metabolismo , Receptores de Dopamina D5 , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal , Relación Estructura-Actividad , Transfección

RESUMEN

Tinea capitis is a dermatophyte infection that occurs mainly in childhood; there are few reports, in Brazil, in adolescents and adults. The detection of asymptomatic carriers is of great importance in the disease control. From February 1998 to February 1999, a study was performed at the outpatient Dermatologic Unit of Instituto de Puericultura e Pediatria Martagão Gesteira (Universidade Federal do Rio de Janeiro, Brasil) to verify the frequency of asymptomatic carriers and tinea capitis between 79 adolescents, adults and elderly who lived in the same household of 56 children (0-12 years) with tinea capitis. Of these, one female and one male adults (2.5%) were asymptomatic carriers and the cultures revealed Trichophyton tonsurans and Microsporum canis respectively. One female adolescent and two female adults (3.8%) had tinea capitis and all cultures revealed Trichophyton tonsurans. The study has shown that adolescents and adults who live in the same household of children with tinea capitis may be sick or asymptomatic carriers.

Asunto(s)

Portador Sano/diagnóstico , Tiña del Cuero Cabelludo/transmisión , Adolescente , Adulto , Anciano , Portador Sano/microbiología , Niño , Preescolar , Femenino , Vivienda , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Tiña del Cuero Cabelludo/diagnóstico

RESUMEN

The synergistic response of cells to the stimulation of multiple receptors has been ascribed to receptor cross talk; however, the specific molecules that mediate the resultant signal amplification have not been defined. Here a 24-kilodalton single transmembrane protein, designated calcyon, we functionally characterize that interacts with the D1 dopamine receptor. Calcyon localizes to dendritic spines of D1 receptor-expressing pyramidal cells in prefrontal cortex. These studies delineate a mechanism of Gq- and Gs-coupled heterotrimeric GTP-binding protein-coupled receptor cross talk by which D1 receptors can shift effector coupling to stimulate robust intracellular calcium (Ca2+i) release as a result of interaction with calcyon. The role of calcyon in potentiating Ca2+-dependent signaling should provide insight into the D1 receptor-modulated cognitive functions of prefrontal cortex.

Asunto(s)

Proteínas de la Membrana/metabolismo , Corteza Prefrontal/metabolismo , Células Piramidales/metabolismo , Receptor Cross-Talk , Receptores de Dopamina D1/metabolismo , Secuencia de Aminoácidos , Animales , Benzazepinas/farmacología , Encéfalo/citología , Encéfalo/metabolismo , Calcio/metabolismo , Señalización del Calcio , Línea Celular , AMP Cíclico/metabolismo , Dendritas/química , Dendritas/metabolismo , Agonistas de Dopamina/farmacología , Femenino , Proteínas de Unión al GTP Heterotriméricas/metabolismo , Humanos , Macaca mulatta , Proteínas de la Membrana/análisis , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Datos de Secuencia Molecular , Corteza Prefrontal/citología , Células Piramidales/química , Conejos , Receptores de Dopamina D1/análisis , Receptores de Neurotransmisores/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Transducción de Señal , Técnicas del Sistema de Dos Híbridos

RESUMEN

We have analyzed the role of N-linked glycosylation in functional cell surface expression of the D1 and D5 dopamine receptor subtypes. Treatment of transfected HEK 293 cells with tunicamycin, an inhibitor of N-linked oligosaccharide addition, was found to prevent localization of D5 receptors in the plasma membrane. In contrast, tunicamycin treatment had no effect on the plasma membrane localization of the D1 receptor. Polymerase chain reaction mutagenesis was used to generate a panel of D5 receptors containing mutations in the three predicted sites of N-linked glycosylation. Expression of mutant receptors indicated that glycosylation of residue N7 was the major determinant of D5 receptor plasma membrane localization. Mutation of a comparable site in the D1 receptor at position N5 had no effect on the delivery of the D1 receptor to the cell surface. Tunicamycin treatment during receptor biosynthesis, but not N-glycosidase F digestion of mature receptors, abrogated binding of the D5 receptor antagonist [(3)H]SCH23390, suggesting that while oligosaccharide moieties play a key role in the cell surface expression of D5 receptors, they do not appear to contribute to the receptor's ligand binding properties. Together, our data indicate a differential requirement for N-linked glycosylation in functional cell surface expression of D1 and D5 dopamine receptors.

Asunto(s)

Membrana Celular/metabolismo , Receptores de Dopamina D1/metabolismo , Membrana Celular/efectos de los fármacos , Células Cultivadas , Glicosilación , Humanos , Ligandos , Mutación , Oligosacáridos/farmacología , Receptores de Dopamina D1/genética , Receptores de Dopamina D5 , Transfección , Tunicamicina/farmacología

RESUMEN

DARPP-32 (dopamine- and cyclic AMP-regulated phosphoprotein, apparent molecular weight of 32,000) is part of the D1 dopamine receptor signal transduction cascade. Both the D1 receptor and DARPP-32 are found in the caudate putamen, but it is not known if they co-localize in the medium-sized spiny neurons. In the present study, double-labelling immunocytochemistry was used to simultaneously localize the D1 receptor and DARPP-32 in the rat caudate-putamen. The neuropil was heavily and uniformly immunoreactive for both the D1 receptor and DARPP-32. All cell bodies immunopositive for the D1 receptor were immunopositive for DARPP-32. The D1 receptor was not detectable, however, in nearly half of the DARPP-32-containing cell bodies. DARPP-32 is present in striatopallidal and striatonigral projections. The D1 receptor co-localized with DARPP-32 in fibres of the entopeduncular nucleus and the pars reticulata of the substantia nigra. In the globus pallidus, however, D1 receptor immunoreactivity was barely detectable, while DARPP-32 immunolabelling of axons and axon terminals was intense. These data suggest that the striatal somata containing both the D1 receptor and DARPP-32 project to the entopeduncular nucleus and substantia nigra, whereas somata containing only DARPP-32 immunoreactivity project to the globus pallidus. Thus, the differences in expression of the D1 receptor and of DARPP-32 within striatal cell bodies are likely reflected in their projections. The co-localization of the D1 receptor and DARPP-32 is consistent with the known regulation of DARPP-32 phosphorylation by D1 receptor activation. The demonstration of a large population of striatal neurons that contain DARPP-32 but apparently do not contain D1 receptors substantiates the premise that these cells have an alternative signal transduction pathway. Subsequent studies are needed to search for a signal transduction pathway for these neurons analogous to the dopamine D1 receptor pathway.

Asunto(s)

Núcleo Caudado/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Neuronas/metabolismo , Fosfoproteínas , Putamen/metabolismo , Receptores de Dopamina D1/metabolismo , Animales , Cuerpo Estriado/fisiología , Fosfoproteína 32 Regulada por Dopamina y AMPc , Inmunohistoquímica , Masculino , Ratas , Ratas Sprague-Dawley , Transmisión Sináptica , Distribución Tisular

RESUMEN

Previous film autoradiographic studies demonstrated that, during corticogenesis, dopamine receptors of the D1 class are abundant in the embryonic primate cerebral wall. In the present study, we expand these findings by identifying the cellular elements of the fetal occipital cerebral wall expressing D1 and D5 subtypes of the D1 dopamine receptor class. We have examined tissue from monkey fetuses collected at 70, 90 and 120 days of gestation using antibodies directed against C-termini of the D1 and D5 dopamine receptors. At all three embryonic ages studied, we found D1 and D5 receptors expressed by multiple cell types of the embryonic cerebral wall. Both D1 and D5 receptor proteins are produced by pyramidal neurons of the cortical plate and by a variety of interstitial neurons of the subplate and intermediate zones. D1 and D5 receptors are also present in cells of the proliferative ventricular and subventricular zones, some of which were identified as dividing cells. In addition, D1 and D5 receptors are detectable in the protoplasmic astroglial and ependymal cells distinguishable in monkey fetuses collected at 120 days of gestation. Some cellular elements of the embryonic monkey cerebral wall express only one subtype of the D1 dopamine receptor class. For example, embryonic Cajal-Retzius neurons in the marginal zone and migrating neurons in the intermediate zone are immunoreactive only to D5 antisera. In contrast, radial glia can be labeled only with D1 receptor-specific antisera. Finally, only D1 receptors are detectable in the blood vessels penetrating the embryonic monkey cerebral wall. Based on these observations, we propose that dopamine receptors of the D1 class play an important role in regulating cerebral cortical formation and that D1 and D5 receptor subtypes may participate in regulation of different aspects of this process.

Asunto(s)

Corteza Cerebral/embriología , Regulación del Desarrollo de la Expresión Génica , Neuronas/metabolismo , Receptores de Dopamina D1/biosíntesis , Corteza Visual/embriología , Animales , Vasos Sanguíneos/embriología , Vasos Sanguíneos/metabolismo , Corteza Cerebral/irrigación sanguínea , Corteza Cerebral/citología , Desarrollo Embrionario y Fetal , Feto , Edad Gestacional , Macaca mulatta , Neuronas/clasificación , Neuronas/citología , Receptores de Dopamina D5 , Corteza Visual/irrigación sanguínea , Corteza Visual/citología

RESUMEN

This study followed 120 chronic pain patients referred to a multidisciplinary pain center. The referral diagnosis for many patients, such as "chronic pain," "psychogenic pain," or "lumbar strain," was frequently found to be incomplete or inaccurate (40%) following a multidisciplinary evaluation that used appropriate diagnostic studies, including magnetic resonance imaging, computed tomography, nerve blocks, and qualitative flowmeter. Significant abnormalities were discovered in 76% of the diagnostic tests. An organic origin for pain was found in 98% of these patients. The patients were discharged with objective verification of diagnoses including facet disease, nerve entrapment, temporomandibular joint disease, thoracic outlet syndrome, and herniated discs.

Asunto(s)

Errores Diagnósticos , Jurisprudencia , Dolor/diagnóstico , Dolor/etiología , Adolescente , Adulto , Anciano , Enfermedad Crónica , Electromiografía , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Derivación y Consulta , Tomografía Computarizada por Rayos X

RESUMEN

Dopamine receptors are the principal targets of drugs used in the treatment of schizophrenia. Among the five mammalian dopamine-receptor subtypes, the D4 subtype is of particular interest because of its high affinity for the atypical neuroleptic clozapine. Interest in clozapine stems from its effectiveness in reducing positive and negative symptoms in acutely psychotic and treatment-resistant schizophrenic patients without eliciting extrapyramidal side effects. We have produced a subtype-specific antibody against the D4 receptor and localized it within specific cellular elements and synaptic circuits of the central nervous system. The D4-receptor antibody labelled GABAergic neurons in the cerebral cortex, hippocampus, thalamic reticular nucleus, globus pallidus and the substantia nigra (pars reticulata). Labelling was also observed in a subset of cortical pyramidal cells. Our findings suggest that clozapine's beneficial effects in schizophrenia may be achieved, in part, through D4-mediated GABA modulation, possibly implicating disinhibition of excitatory transmission in intrinsic cortical, thalamocortical and extrapyramidal pathways.

Asunto(s)

Química Encefálica , Neuronas/química , Receptores de Dopamina D2/análisis , Ácido gamma-Aminobutírico/metabolismo , Animales , Especificidad de Anticuerpos , Ganglios Basales/química , Ganglios Basales/metabolismo , Secuencia de Bases , Línea Celular , Cartilla de ADN , Escherichia coli , Humanos , Técnicas Inmunológicas , Interneuronas/química , Macaca mulatta , Datos de Secuencia Molecular , Neuronas/metabolismo , Neuronas/ultraestructura , Receptores de Dopamina D2/inmunología , Receptores de Dopamina D4 , Proteínas Recombinantes/inmunología , Tálamo/química , Tálamo/metabolismo

RESUMEN

The pathways governing signal transduction in the mesocortical and nigrostriatal dopamine systems of the brain are of central importance in a variety of drug actions and neurological diseases. We have analyzed the regional, cellular, and subcellular distribution of the closely related D1 and D5 subtypes of dopamine receptors in the cerebral cortex and selected subcortical structures of rhesus monkey using subtype specific antibodies. The distribution of D1 and D5 receptors was highly differentiated in subcortical structures. In the neostriatum, both D1 and to a lesser extent D5 antibodies labeled medium spiny neurons, while only D5 antibodies labeled the large aspiny neurons typical of cholinergic interneurons. In the caudate nucleus, D1 labeling was concentrated in the spines and shafts of projection neurons, whereas D5 antibodies predominantly labeled the shafts, and less commonly, the spines of these cells. The D1 receptor was abundantly expressed in the neuropil of the substantia nigra pars reticulata while the D5 antibodies labeled only a few scattered cell bodies in this structure. Conversely, D5 antibodies labeled cholinergic neurons in the basal forebrain more intensely than D1 antibodies. Within the cerebral cortex and hippocampus, D1 and D5 antibody labeling was prominent in pyramidal cells. Double-label experiments revealed that the two receptors were frequently coexpressed in neurons of both structures. Ultrastructurally, D1 receptors were especially prominent in dendritic spines whereas dendritic shafts were more prominently labeled by the D5 receptor. The anatomical segregation of the D1 and D5 receptors at the subcellular level in cerebral cortex and at the cellular level in subcortical areas suggest that these closely related receptors may be preferentially associated with different circuit elements and may play distinct regulatory roles in synaptic transmission.

Asunto(s)

Encéfalo/metabolismo , Receptores de Dopamina D1/metabolismo , Fracciones Subcelulares/metabolismo , Animales , Secuencia de Bases , Corteza Cerebral/citología , Corteza Cerebral/metabolismo , Hipocampo/citología , Hipocampo/metabolismo , Immunoblotting , Inmunohistoquímica , Macaca mulatta , Microscopía Electrónica , Datos de Secuencia Molecular , Sondas de Oligonucleótidos/genética , Receptores de Dopamina D5 , Distribución Tisular

RESUMEN

Deformed (Dfd) is a Drosophila homeotic selector gene required for normal development of maxillary segment morphology in the larval and adult head. Consistent with this function, Dfd transcripts are restricted to epidermal, mesodermal and neural cells in the embryonic mandibular and maxillary primordia. Previous studies have identified a far upstream element in Dfd sequences which functions as an epidermal-specific autoregulatory enhancer. In a search through 35 kb of Dfd sequences for additional transcriptional control elements, we have identified a 3.2 kb DNA fragment containing an enhancer that mimics the expression of Dfd in the subesophageal ganglion of the embryonic central nervous system. This Neural autoregulatory enhancer (NAE) maps in the large Dfd intron just upstream of the homeobox exon and requires Dfd protein function for its full activity. A 608 bp NAE subfragment retains regulatory function that is principally localized in the subesophageal ganglion. This small region of the Drosophila melanogaster genome contains numerous blocks of sequence conservation with a comparable region from the Dfd locus of D.hydei. A pair of conserved blocks of NAE sequence match a Dfd protein binding site in the epidermal autoregulatory element, while another conserved sequence motif is repeated multiple times within the 608 bp subelement.

Asunto(s)

Proteínas de Unión al ADN/genética , Drosophila/genética , Elementos de Facilitación Genéticos , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio , Intrones , Animales , Secuencia de Bases , Evolución Biológica , Drosophila/embriología , Proteínas de Drosophila , Genes de Insecto , Datos de Secuencia Molecular , Neuronas/metabolismo , ARN Mensajero/genética

RESUMEN

To achieve a better understanding of how D5 dopamine receptors mediate the actions of dopamine in brain, we have developed antibodies specific for the D5 receptor. D5 antibodies reacted with recombinant baculovirus-infected Sf9 cells expressing the D5 receptor but not with the D1 receptor or a variety of other catecholaminergic and muscarinic receptors. Epitope-tagged D5 receptors expressed in mammalian cells were reactive with both D5 antibodies and an epitope-specific probe. A mixture of N-linked glycosylated polypeptides and higher molecular-mass species was detected on immunoblots of membrane fractions of D5-transfected cells and also of primate brain. D5 receptor antibodies intensely labeled pyramidal neurons in the prefrontal cortex, whereas spiny medium-sized neurons and aspiny large interneurons of the caudate nucleus were relatively lightly labeled. Antibodies to the D5 dopamine receptor should prove important in experimentally determining specific roles for the D5 and D1 receptors in cortical processes and diseases.

Asunto(s)

Química Encefálica , Receptores de Dopamina D1 , Receptores Dopaminérgicos/inmunología , Receptores Dopaminérgicos/aislamiento & purificación , Secuencia de Aminoácidos , Animales , Especificidad de Anticuerpos , Secuencia de Bases , Compartimento Celular , Epítopos , Técnica del Anticuerpo Fluorescente , Lóbulo Frontal/anatomía & histología , Humanos , Hibridación in Situ , Macaca mulatta , Masculino , Datos de Secuencia Molecular , ARN Mensajero/aislamiento & purificación , Receptores Dopaminérgicos/clasificación , Receptores Dopaminérgicos/genética , Receptores de Dopamina D5 , Proteínas Recombinantes/aislamiento & purificación , Distribución Tisular

RESUMEN

A truncated dopamine D3-receptor-like mRNA, named D3nf, predicts a protein that differs from the D3-receptor only in the carboxyl terminus. However, such a protein has lost the predicted membrane topology typically found for G protein-coupled receptors. Results presented here show that D3nf mRNA arises from the D3-encoded primary transcript via alternative splicing. This splicing, however, appears to involve cleavage of an unusual 3' splice site. Therefore, we tested the possibility that D3nf mRNA results from a splicing error. If this were the case, D3nf mRNA would be expected to be present in the cytoplasm only at very low amounts, and it would not be expected to be translated into protein. However, the relative abundance of cytoplasmic D3/D3nf mRNA in human cortical tissues was found to be similar. Furthermore, we raised polyclonal antisera against the predicted carboxyl-terminal peptide sequence of D3nf that reacts specifically with a protein expressed in stably D3nf mRNA-expressing COS 7 cells. The use of this antiserum also revealed the presence of a approximately 68 kDa D3nf-like immunoreactive protein in human brain, suggesting that the atypically processed D3nf mRNA is translated.

Asunto(s)

Corteza Cerebral/metabolismo , ARN Mensajero/genética , Receptores de Dopamina D2 , Receptores Dopaminérgicos/genética , Anciano , Anciano de 80 o más Años , Secuencia de Aminoácidos , Secuencia de Bases , Línea Celular , Cartilla de ADN , Femenino , Humanos , Immunoblotting , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Biosíntesis de Proteínas , ARN Mensajero/metabolismo , Receptores Dopaminérgicos/metabolismo , Receptores de Dopamina D3

Asunto(s)

Cocaína , Regulación de la Expresión Génica/efectos de los fármacos , Sistema Nervioso/metabolismo , Trastornos Relacionados con Opioides/genética , Trastornos Relacionados con Sustancias/genética , Animales , Humanos , Trastornos Relacionados con Opioides/metabolismo , Trastornos Relacionados con Sustancias/metabolismo

RESUMEN

In an attempt to characterize proteins which are enriched or specifically expressed in the locus coeruleus (LC), a region of the brain which plays a critical role in opiate dependence and withdrawal, we have screened a bovine LC cDNA library with an LC minus cerebellum subtracted cDNA probe and isolated several (38) positively hybridizing clones. DNA sequence analysis revealed that two of the clones encoded ezrin and osteonectin, proteins normally associated with cell growth and morphology in peripheral tissues. Regional northern blots from bovine brain and in situ hybridization studies in rat show that ezrin is expressed at high levels in the LC with only low levels detectable in other brain regions. Osteonectin is also abundant in the LC, but in contrast to ezrin, is expressed at high levels in the dorsal raphe and substantia nigra. The results indicate that two proteins, ezrin and osteonectin, are highly enriched in the LC. This raises the possibility that these polypeptides, which play a role in the morphological response of some non-neuronal cell types to growth factors and to other intracellular signals, may also regulate these properties in noradrenergic and other selected neurons in the brain.