The effect of cephalic transection on the micromorphological changes in the ventral nerve cord-neurosecretory system of earthworm,Metaphire peguana (Rosa, 1890) during anterior regeneration
Transection of anterior 5 segments inMetaphire peguana engenders characteristic changes in the functional activity of the ventral nerve cord-neurosecretory system in the event of cephalic regeneration. Of the two types of neurosecretory cells, the moderately stained cells remain more susceptible when the cell structure, location of nucleus, amount of secretory inclusions and their transportation to the zone of accumulation are considered. Overall engorgement of neurosecretory substances refrained from axonal transport, moderate axonal flow coupled with slight depletion and finally acute depletion at 24, 48 and 72 hr after amputation respectively are some of the notable features registered in course of this investigation. Disarray in the sequential changes involved in the secretory dynamics of neurosecretory cells, as well as extent of NSM accumulation both within and outer periphery of the ganglia provide evidence for the utilisation of material through repaired vascular systems during regenerative proliferations of anterior segments.
KeywordsMetaphire peguana neurosecretory cells NSM regeneration secretory dynamics
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