Hemorrhage or hypotension induces extensive Foslike immunoreactivity in the magnocellular neurosecretory cells in the supraoptic nucleus of the hypothalamus in rat, especially in the vasopressin neurons. The present s...Hemorrhage or hypotension induces extensive Foslike immunoreactivity in the magnocellular neurosecretory cells in the supraoptic nucleus of the hypothalamus in rat, especially in the vasopressin neurons. The present study was to explore the neurotransmitter mediating this effect. Microinfusion of the alpha-adrenergic blocker into the supraoptic nucleus reduced the hypotension-induced Fos, whereas beta-antagonist did not affect it significantly. Alpha1- and alpha2-antagonist, prazosin and yohimbine,both reduced the Fos-positive cell counts. However, the effective dosage of yohimbine was much larger. Alpha1-agonist, methoxamine, induced abundant Fos-like immnnoreactivity in the vasopressin cells in this nucleus,while beta-and alpha2-agonist did not elicit such effect.Administration of the noradrenergic re-uptake inhibitor,desipramine, to this nucleus to locally accumulate the spontaneously released noradrenaline from the nerve terminals also induced Fos expression, mostly in the vasopressin cells.展开更多
Eudrilus eugeniae （Kinberg）, well known vermicomposting earthworms, are often subjected to predator attacks leading to loss of body parts due to their surface living habit. Thus nature has gifted them the power of r...Eudrilus eugeniae （Kinberg）, well known vermicomposting earthworms, are often subjected to predator attacks leading to loss of body parts due to their surface living habit. Thus nature has gifted them the power of regeneration of lost body parts. As neurosecretion is the sole source of hormone in oligochaetes, we hypothesize that neurohormone secreted from the neurosecretory cells of the central nervous system （CNS） will control the phenomenon of regeneration in earthworms. In Eudrilus eugeniae, appearance of regeneration blastema was noticed within 72 h of posterior amputation. In fact, posterior amputation brought about multiple cytoplasmic alteration in the neurosecretory cells （NSCs） viz. deep stained A cells and moderately stained B cells in cerebral ganglia, deep stained ＇U＇ cells and moderately stained B cells in the sub-esophageal and ventral nerve cord ganglia. Massive depletion followed by marginal accumulation of NSM in the NSCs following 24 h and 48 h of amputation were recorded. Thereafter （72 h and 96 h of amputation） moderate to massive engorgement of NSM in the B cells, coupled with spectacular increase in number of A cells were noticed. Sequential changes involved in the secretory dynamics of NSCs, as well as, NSM accumulation both within and periphery of the ganglia （perineurium） provides evidence for the utilization of materials through repaired vascular systems during posterior regeneration in E. eugeniae.展开更多
文摘Hemorrhage or hypotension induces extensive Foslike immunoreactivity in the magnocellular neurosecretory cells in the supraoptic nucleus of the hypothalamus in rat, especially in the vasopressin neurons. The present study was to explore the neurotransmitter mediating this effect. Microinfusion of the alpha-adrenergic blocker into the supraoptic nucleus reduced the hypotension-induced Fos, whereas beta-antagonist did not affect it significantly. Alpha1- and alpha2-antagonist, prazosin and yohimbine,both reduced the Fos-positive cell counts. However, the effective dosage of yohimbine was much larger. Alpha1-agonist, methoxamine, induced abundant Fos-like immnnoreactivity in the vasopressin cells in this nucleus,while beta-and alpha2-agonist did not elicit such effect.Administration of the noradrenergic re-uptake inhibitor,desipramine, to this nucleus to locally accumulate the spontaneously released noradrenaline from the nerve terminals also induced Fos expression, mostly in the vasopressin cells.
文摘Eudrilus eugeniae （Kinberg）, well known vermicomposting earthworms, are often subjected to predator attacks leading to loss of body parts due to their surface living habit. Thus nature has gifted them the power of regeneration of lost body parts. As neurosecretion is the sole source of hormone in oligochaetes, we hypothesize that neurohormone secreted from the neurosecretory cells of the central nervous system （CNS） will control the phenomenon of regeneration in earthworms. In Eudrilus eugeniae, appearance of regeneration blastema was noticed within 72 h of posterior amputation. In fact, posterior amputation brought about multiple cytoplasmic alteration in the neurosecretory cells （NSCs） viz. deep stained A cells and moderately stained B cells in cerebral ganglia, deep stained ＇U＇ cells and moderately stained B cells in the sub-esophageal and ventral nerve cord ganglia. Massive depletion followed by marginal accumulation of NSM in the NSCs following 24 h and 48 h of amputation were recorded. Thereafter （72 h and 96 h of amputation） moderate to massive engorgement of NSM in the B cells, coupled with spectacular increase in number of A cells were noticed. Sequential changes involved in the secretory dynamics of NSCs, as well as, NSM accumulation both within and periphery of the ganglia （perineurium） provides evidence for the utilization of materials through repaired vascular systems during posterior regeneration in E. eugeniae.
