RESUMEN
Multiplexed fluorescence in situ hybridization techniques have enabled cell-type identification, linking transcriptional heterogeneity with spatial heterogeneity of cells. However, inaccurate cell segmentation reduces the efficacy of cell-type identification and tissue characterization. Here, we present a method called Spot-based Spatial cell-type Analysis by Multidimensional mRNA density estimation (SSAM), a robust cell segmentation-free computational framework for identifying cell-types and tissue domains in 2D and 3D. SSAM is applicable to a variety of in situ transcriptomics techniques and capable of integrating prior knowledge of cell types. We apply SSAM to three mouse brain tissue images: the somatosensory cortex imaged by osmFISH, the hypothalamic preoptic region by MERFISH, and the visual cortex by multiplexed smFISH. Here, we show that SSAM detects regions occupied by known cell types that were previously missed and discovers new cell types.
Asunto(s)
Encéfalo/citología , Biología Computacional/métodos , Perfilación de la Expresión Génica/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Imagenología Tridimensional/métodos , Hibridación Fluorescente in Situ/métodos , Análisis de la Célula Individual/métodos , Algoritmos , Animales , Encéfalo/diagnóstico por imagen , Simulación por Computador , Ratones , Neuronas/citología , Neuronas/metabolismo , Área Preóptica/citología , Área Preóptica/diagnóstico por imagen , Corteza Somatosensorial/citología , Corteza Somatosensorial/diagnóstico por imagen , Transcriptoma/genética , Corteza Visual/citología , Corteza Visual/diagnóstico por imagenRESUMEN
Hypothalamic nuclei in the preoptic and anterior hypothalamic region (POAH) are critically involved in thermoregulation and neuroendocrine regulation and can be displaced by craniopharyngiomas (CPs). We aimed to locate the POAH by visualizing hypothalamic thermoregulation through task-related functional magnetic resonance imaging (fMRI) to guide hypothalamus protection intraoperatively. Nine adult healthy volunteers (HVs) and thirty-two adult primary CP patients underwent task-related fMRI for POAH localization by warm (60° C) and cold (0° C) cutaneous thermoreceptor stimulation. Approach selection and intraoperative POAH protection were performed based on preoperative POAH localization. In all HVs and patients, significant single positive blood oxygen level-dependent (BOLD) signal changes were located in the POAH. The BOLD activity was significantly greater for cold (P=0.03) and warm (P=0.03) stimuli in patients than in HVs. Gross total resection and near-total resection were achieved in 28 (87.5%) and 4 (12.5%) patients, respectively. New-onset diabetes insipidus and new-onset hypopituitarism occurred in 6 patients (18.8%) and 10 patients (31.3%), respectively. Our findings suggest that cutaneous thermoreceptor stimulation could accurately activate the hypothalamic thermoregulatory center and allow POAH localization through task-related fMRI. Preoperative POAH localization could help neurosurgeons protect hypothalamic function intraoperatively. The CP patients were more sensitive to thermal stimulation.
Asunto(s)
Núcleo Hipotalámico Anterior/diagnóstico por imagen , Regulación de la Temperatura Corporal/fisiología , Craneofaringioma/diagnóstico por imagen , Neoplasias Hipofisarias/diagnóstico por imagen , Área Preóptica/diagnóstico por imagen , Adulto , Frío , Femenino , Calor , Humanos , Imagen por Resonancia Magnética , Masculino , Neuronas/fisiologíaRESUMEN
Cutaneous vasoconstrictor nerves regulate heat retention, and are activated by falls in skin or core temperature. The efferent pathways controlling this process originate within the preoptic area. A descending GABAergic pathway, activated by warm skin or core, indirectly inhibits sympathetic premotor neurons in the medullary raphé. Those premotor neurons drive cutaneous vasoconstriction via excitatory glutamatergic and serotonergic connections to spinal preganglionic neurons. Cold skin and/or cold core temperatures activate a direct preoptic-to-raphé excitatory pathway. The balance of inhibitory and excitatory influences reaching the medullary raphé determines cutaneous blood flow. During fever, prostaglandin E2 inhibits preoptic GABAergic neurons, resulting in disinhibition of the excitatory preoptic-to-raphé pathway, and hence, cutaneous vasoconstriction. A weaker, parallel source of descending excitatory drive reaches cutaneous preganglionic neurons from the rostral ventrolateral medulla. Sweating follows local heating of the preoptic area in cats and monkeys, and heated humans show sweating-related activation of this same region in functional magnetic resonance imaging (fMRI) studies. A descending pathway that drives sweating has been traced in cats from the hypothalamus to putative premotor neurons in the parafacial region at the pontomedullary junction. The homologous parafacial region in humans also shows sweating-related activation in fMRI studies. The central pathways that drive active vasodilatation in human nonacral skin remain unknown.
Asunto(s)
Regulación de la Temperatura Corporal/fisiología , Vías Eferentes/fisiología , Piel/irrigación sanguínea , Piel/inervación , Sudoración/fisiología , Animales , Presión Sanguínea/fisiología , Vías Eferentes/diagnóstico por imagen , Humanos , Neuronas/fisiología , Área Preóptica/citología , Área Preóptica/diagnóstico por imagen , Área Preóptica/fisiopatologíaRESUMEN
Maternal behavior and anxiety are potently modulated by the brain corticotropin-releasing factor (CRF) system postpartum. Downregulation of CRF in limbic brain regions is essential for appropriate maternal behavior and an adaptive anxiety response. Here, we focus our attention on arguably the most important brain region for maternal behavior, the hypothalamic medial preoptic area (MPOA). Within the MPOA, mRNA for CRF receptor subtype 1 (protein: CRFR1, gene: Crhr1) was more abundantly expressed than for subtype 2 (protein: CRFR2, gene: Crhr2), however expression of Crhr1, Crhr2 and CRF-binding protein (protein: CRFBP, gene: Crhbp) mRNA was similar between virgin and lactating rats. Subtype-specific activation of CRFR, predominantly CRFR1, in the MPOA decreased arched back nursing and total nursing under non-stress conditions. Following acute stressor exposure, only CRFR1 inhibition rescued the stress-induced reduction in arched back nursing while CRFR1 activation prolonged the decline in nursing. Furthermore, inhibition of CRFR1 strongly increased maternal aggression in the maternal defense test. CRFR1 activation had anxiogenic actions and reduced locomotion on the elevated plus-maze, however neither CRFR1 nor R2 manipulation affected maternal motivation. In addition, activation of CRFR1, either centrally or locally in the MPOA, increased local oxytocin release. Finally, inhibition of CRFBP (a potent regulator of CRFR activity) in the MPOA did not affect any of the maternal parameters investigated. In conclusion, activity of CRFR in the MPOA, particularly of subtype 1, needs to be dampened during lactation to ensure appropriate maternal behavior. Furthermore, oxytocin release in the MPOA may provide a regulatory mechanism to counteract the negative impact of CRFR activation on maternal behavior.
Asunto(s)
Regulación de la Expresión Génica/fisiología , Lactancia/fisiología , Conducta Materna/fisiología , Oxitocina/metabolismo , Área Preóptica/metabolismo , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Análisis de Varianza , Animales , Animales Recién Nacidos , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Hormona Liberadora de Corticotropina/farmacología , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Antagonistas de Hormonas/farmacología , Masculino , Conducta Materna/psicología , Aprendizaje por Laberinto/fisiología , Microdiálisis , Área Preóptica/diagnóstico por imagen , Pirimidinas/farmacología , Pirroles/farmacología , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Hormona Liberadora de Corticotropina/agonistas , Receptores de Hormona Liberadora de Corticotropina/antagonistas & inhibidoresRESUMEN
In a previous study, we demonstrated that androgenic-anabolic steroids increased aromatase expression in the bed nucleus of stria terminalis and preoptic area in rat brain, as evaluated using autoradiography with [11C]vorozole, a potential positron emission tomography tracer for aromatase. In this study, we explored whether the increase in aromatase binding is mediated via androgen receptors and whether this increase occurs in neurons or glial cells. Rats were given nandrolone decanoate (15 mg/kg body weight once every 3 days) and flutamide (20 mg/kg/day) alone or in combination for 20 days. Results indicated a significant increase of [11C]vorozole binding by nandrolone decanoate in the bed nucleus of the stria terminalis and preoptic area, as in our previous study. Flutamide treatment, on the other hand, decreased [11C]vorozole binding in the bed nucleus of the stria terminalis, preoptic area, and medial amygdala. Immunohistochemical examination demonstrated that upregulation of aromatase expression occurred in neurons. Our findings suggest that aromatase is regulated through an androgen receptor-mediated system. This aromatase-specific tracer and the positron emission tomography technique could be useful for exploring the role of aromatase in anabolic androgenic steroids abusers.
Asunto(s)
Andrógenos/farmacología , Aromatasa/metabolismo , Encéfalo/efectos de los fármacos , Flutamida/farmacología , Neuronas/efectos de los fármacos , Receptores Androgénicos/efectos de los fármacos , Amígdala del Cerebelo/diagnóstico por imagen , Amígdala del Cerebelo/efectos de los fármacos , Amígdala del Cerebelo/enzimología , Antagonistas de Andrógenos/farmacología , Animales , Inhibidores de la Aromatasa/metabolismo , Unión Competitiva/efectos de los fármacos , Unión Competitiva/fisiología , Encéfalo/diagnóstico por imagen , Encéfalo/enzimología , Mapeo Encefálico , Radioisótopos de Carbono , Masculino , Neuronas/enzimología , Tomografía de Emisión de Positrones , Área Preóptica/diagnóstico por imagen , Área Preóptica/efectos de los fármacos , Área Preóptica/enzimología , Ratas , Ratas Sprague-Dawley , Receptores Androgénicos/metabolismo , Núcleos Septales/diagnóstico por imagen , Núcleos Septales/efectos de los fármacos , Núcleos Septales/enzimología , Triazoles/metabolismo , Triazoles/farmacocinética , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/fisiologíaRESUMEN
Brain mechanisms for the refractory period that characteristically follows ejaculation in animals and human are poorly understood. The possibility of active inhibition of brain areas being responsible for the post-ejaculatory inhibitory state has not been ruled out. Using Blood Oxygen Level Dependent (BOLD) functional magnetic resonance imaging (fMRI) we have mapped brain areas in healthy young volunteers immediately after ejaculation. Functional imaging of the brain for 30 minutes beginning after three minutes of ejaculation induced by masturbation showed spatio-temporal activation in amygdala, temporal lobes and septal areas. The septal areas were observed to be active for a shorter duration than the amygdala and the temporal lobe. Thus the temporal sequence of involvement of the above neural structures may contribute to temporary inhibition of sexual arousal/penile erection during the post-ejaculatory refractory period in humans.
Asunto(s)
Encéfalo/fisiología , Eyaculación/fisiología , Imagen por Resonancia Magnética/métodos , Adulto , Amígdala del Cerebelo/diagnóstico por imagen , Amígdala del Cerebelo/fisiología , Encéfalo/diagnóstico por imagen , Imagen Eco-Planar/métodos , Lóbulo Frontal/diagnóstico por imagen , Lóbulo Frontal/fisiología , Giro del Cíngulo/diagnóstico por imagen , Giro del Cíngulo/fisiología , Humanos , Masculino , Masturbación , Área Preóptica/diagnóstico por imagen , Área Preóptica/fisiología , Radiografía , Tiempo de Reacción , Periodo Refractario Electrofisiológico/fisiología , Tabique del Cerebro/diagnóstico por imagen , Tabique del Cerebro/fisiología , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/fisiología , Factores de TiempoRESUMEN
Although the brain plays a crucial role in the control of micturition, little is known about the structures involved. Identification of these areas is important, because their dysfunction is though to cause urge incontinence, a major problem in the elderly. In the cat, three areas in the brainstem and diencephalon are specifically implicated in the control of micturition: the dorsomedial pontine tegmentum, the periaqueductal grey, and the preoptic area of the hypothalamus. PET scans were used to test whether these areas are also involved in human micturition. Seventeen right-handed male volunteers were scanned during the following four conditions: (i) 15 min prior to micturition during urine withholding: (ii) during micturition; (iii) 15 min after micturition; (iv) 30 min after micturition. Ten of the 17 volunteers were able to micturate during scanning. micuturition was associated with increased blood flow in the right dorsomedial pontine tegmentum, the periaqueductal grey, the hypothalamus and the right inferior frontal gyrus. Decreased blood flow was found in the right anterior cingulate gyrus when urine was withheld. The other seven volunteers were not able to micturate during scanning, although they had a full bladder and tried vigorously to do so. In this group, during these unsuccessful attempts to micturate, increased blood flow was found in the right ventral pontine tegmentum, which corresponds with the hypothesis, formulated from results in cats, that this area controls the motor neurons of the pelvic floor. Increased blood flow was also found in the right inferior frontal gyrus during unsuccessful attempts at micturition, and decreased blood flow in the right anterior cingulate gyrus was found during the withholding of urine. The results suggest that, as that of the cat, the human brainstem contains specific nuclei responsible for the control of micturition, and that the cortical and pontine micturition sites are predominantly on the right side.