RESUMO
In the present work, histochemical and biochemical studies were conducted to analyze changes in the pattern of autonomic innervation during sexual maturation, using the rat epididymis as a model. Glyoxylic acid histochemistry and immunohistochemical studies against dopamine beta-hydroxylase (DbetaH) and acetylcholinesterase (AChE) indicated a reduction in the amount of catecholaminergic and AChE-positive neurons, fibers, and puncta detected in the cauda epididymis of adult rats (120 days old), when compared to immature (40 days) and young adult (60 days) animals. No obvious age-related variations were detected in the few catecholaminergic and AChE-positive fibers and puncta present in the caput region. AChE-positive fibers were found sorting out among epithelial cells and ending free upon the epithelial surface or into the tubular lumen of the cauda region of adult rats. Furthermore, a positive staining for AChE in epithelial cells was also detected in the caput and cauda epididymis in all ages studied. Biochemical analysis confirmed a significant decrease in noradrenaline concentration as well as AChE activity in the cauda epididymis with sexual maturation. Immunohistochemical studies against microtubule-associated protein 1B (MAP 1B), a neuronal cytoskeletal marker, further substantiated the quantitative changes observed in catecholaminergic and AChE-positive neuronal elements in the cauda epididymis. Thus, our results documented segment-specific variations in noradrenaline concentration and AChE activity during epididymal sexual maturation and suggest that such variations result, at least in part, from the refinement of the autonomic innervation pattern with age.
Assuntos
Acetilcolinesterase/metabolismo , Sistema Nervoso Autônomo/enzimologia , Catecolaminas/metabolismo , Epididimo/crescimento & desenvolvimento , Epididimo/inervação , Fatores Etários , Animais , Sistema Nervoso Autônomo/química , Sistema Nervoso Autônomo/crescimento & desenvolvimento , Dopamina beta-Hidroxilase/análise , Epididimo/anatomia & histologia , Fertilidade , Glioxilatos/análise , Imuno-Histoquímica , Masculino , Proteínas Associadas aos Microtúbulos/análise , Tamanho do Órgão , Ratos , Ratos Wistar , Maturidade SexualRESUMO
Adrenal medulla together with the sympathetic nervous system constitute an anatomo functional unit. Both tissues derive from precursor cells which originate from the neural crest and later differentiate during migration into sympathetic neurons or chromaffin cells. Biosynthesis enzymes of catecholamines such as DBH (dopamine beta hydroxylase) and PNMT (phenylethanol amine-N-methyl transferase) as well as the neurotransmitter serotonin , can be detected by immunohistochemical techniques from 15 to 20 prenatal days. Cells migrating along the dorsal aorta could be observed at 15 prenatal days. From day 16 on, three distinct cellular groups could be distinguished according to the intensity of the immunoreactivity: chromaffin, paraganglion and sympathetic ganglion cells. From day 18, chromaffin cells immunostained as DBH' PNMT+ or DBH+ PNMT could be detected differentiating into what would be adrenergic or noradrenergic cells, respectively Progenitor cells migrating from the neural crest to the adrenal cortical blastema reach a micro-environment where glucocorticoids could possibly influence gene expression for PNMT in some of these undifferentiated cells, causing adrenaline synthesis. Serotonin(5HT) immunoreactivity is localized from 17 prenatal days in several groups of the paraganglionic cells where they could be a modulator for chromaffin differentiation.
Assuntos
Medula Suprarrenal/embriologia , Células Cromafins/citologia , Paragânglios Cromafins/citologia , Medula Suprarrenal/citologia , Animais , Biomarcadores , Diferenciação Celular , Linhagem da Célula , Movimento Celular , Dopamina beta-Hidroxilase/análise , Feminino , Técnicas Imunoenzimáticas , Masculino , Crista Neural/citologia , Feniletanolamina N-Metiltransferase/análise , Ratos , Ratos Wistar , Serotonina/análiseRESUMO
Adrenal medulla together with the sympathetic nervous system constitute an anatomo functional unit. Both tissues derive from precursor cells which originate from the neural crest and later differentiate during migration into sympathetic neurons or chromaffin cells. Biosynthesis enzymes of catecholamines such as DBH (dopamine beta hydroxylase) and PNMT (phenylethanol amine-N-methyl transferase) as well as the neurotransmitter serotonin , can be detected by immunohistochemical techniques from 15 to 20 prenatal days. Cells migrating along the dorsal aorta could be observed at 15 prenatal days. From day 16 on, three distinct cellular groups could be distinguished according to the intensity of the immunoreactivity: chromaffin, paraganglion and sympathetic ganglion cells. From day 18, chromaffin cells immunostained as DBH PNMT+ or DBH+ PNMT could be detected differentiating into what would be adrenergic or noradrenergic cells, respectively Progenitor cells migrating from the neural crest to the adrenal cortical blastema reach a micro-environment where glucocorticoids could possibly influence gene expression for PNMT in some of these undifferentiated cells, causing adrenaline synthesis. Serotonin(5HT) immunoreactivity is localized from 17 prenatal days in several groups of the paraganglionic cells where they could be a modulator for chromaffin differentiation.(AU)
Assuntos
Animais , Masculino , Feminino , Ratos , RESEARCH SUPPORT, NON-U.S. GOVT , Medula Suprarrenal/embriologia , Células Cromafins/citologia , Paragânglios Cromafins/citologia , Medula Suprarrenal/citologia , Biomarcadores , Diferenciação Celular , Linhagem da Célula , Movimento Celular , Dopamina beta-Hidroxilase/análise , Técnicas Imunoenzimáticas , Crista Neural/citologia , Feniletanolamina N-Metiltransferase/análise , Ratos Wistar , Serotonina/análiseRESUMO
We have localized at light and electron-microscopic level the growth-associated protein GAP-43 in adrenal gland using single and double labelling immunocytochemistry. Clusters of GAP-43-immunofluorescent chromaffin cells and many immunofluorescent fibres were observed in the medulla. GAP-43-immunoreactive fibres also formed a plexus under the capsule, crossed the cortex and ramified in the zona reticulata. Double labelled sections showed the coexpression of GAP-43 with a subpopulation of tyrosine hydroxylase- and of dopamine-beta-hydroxylase-immunoreactive chromaffin cells. Dual colour immunofluorescence for GAP-43 and calcitonin gene-related peptide (CGRP) revealed that some of the GAP-43-immunoreactive fibres also express CGRP. Pre-embedding electron microscopy showed GAP-43 immunoreactivity associated with the plasma membranes and cytoplasm of noradrenaline-producing chromaffin cells, and with processes of nonmyelin-forming Schwann cells. Immunoreactive unmyelinated axons and terminals were also observed. The immunostained terminals made symmetrical synaptic contacts with chromaffin cells. Immunoreactive unmyelinated fibres and small terminals were present in the cortex. Our results show that GAP-43 is expressed in noradrenergic chromaffin cells and in various types of nerve fibres that innervate the adrenal. Likely origins for these fibres include preganglionic sympathetic fibres which innervate chromaffin cells, postganglionic sympathetic fibres in the cortex, and CGRP containing sensory fibres.
Assuntos
Glândulas Suprarrenais/inervação , Medula Suprarrenal/química , Glicoproteínas de Membrana/análise , Fibras Nervosas/química , Proteínas do Tecido Nervoso/análise , Glândulas Suprarrenais/química , Glândulas Suprarrenais/citologia , Medula Suprarrenal/inervação , Animais , Anticorpos , Peptídeo Relacionado com Gene de Calcitonina/análise , Dopamina beta-Hidroxilase/análise , Imunofluorescência , Proteína GAP-43 , Microscopia Imunoeletrônica , Ratos , Ratos Wistar , Sinapses/ultraestrutura , Tirosina 3-Mono-Oxigenase/análiseRESUMO
1. Immunohistochemical methods were used to identify dopaminergic, noradrenergic, cholinergic and serotonergic axons in cynomolgus monkey prefrontal cortex. 2. The densities of dopaminergic and noradrenergic systems varied in a similar fashion across prefrontal cortical regions, whereas the densities of cholinergic and serotonergic axons were regionally homogeneous. 3. In contrast, the laminar distributions of labeled axons were very different among these four systems. 4. The different patterns of organization of axons arising from these four afferent systems indicate that they may differ substantially in their regulation of prefrontal cortical function.