Responses of Cholinergic and Noncholinergic Renshaw Cell Receptors After Acute and Chronic Exposure to Anticholinesterases.
Annual summary rept. 15 May 81-14 May 82,
IOWA STATE UNIV AMES
Pagination or Media Count:
The fine structural changes in the most ventral regions of the ventral horn of spinal segment L7 have been studied in cats after single and chronic low dose exposure to diisoproylfuorophosphate DFP. Motoneurones of the chronically treated animals show an increase in the number of lysosomes, neurofilaments, and vesicle-like structures. A large number of coated vesicles is observed within axons and axon terminals of both acute and chronically treated animals. Mohrphological evidence of axon and terminal degeneration is seen only in chronically treated animals. Degeneration is revealed by the presence of membrane-bound structures, glycogen granules, lamellar and dense lamellar bodies, increased amounts of smooth axonal endoplasmic reticulum sAER, neurofilaments and accumulation of microtubules. Axonal degeneration in the ventral horn of L7 after chronic low dose exposure to DFP is suggested to be a retrograde process starting at the presynaptic terminals.
- Anatomy and Physiology