Neuromuscular blockade increases motoneurone survival during normal cell death in the chick embryo.

摘要: NATURALLY occurring neuronal cell death is a quantitatively significant event in many developing systems1–5; however, the determinants responsible for some neurones surviving while an equal or even greater number degenerate are still unknown. Neurones which undergo spontaneous degeneration have axons appropriate peripheral area6,7, and it generally believed that those die do so because they losers competition limited of ‘targets’1,8, amount ‘trophic substance’9,10. This study was undertaken attempt to better understand parameters define ‘target’ factors involved survival motoneurones lateral motor column lumbar spinal cord chick. Normally by embryonic day 6 peak approximately 22,000–24,000 found each whereas 9 there 13,500 12, continuing through hatching, consists 11,000–11,500 (unpublished data, also see refs 3, 11). We report here contrary what might be expected12, embryos treated during period normal with botulinum toxin (BTX) curare contain about 5,500 more (a 50% increase) after over. Treatment irreversible nicotinic receptor blocker α-cobratoxin (CT, from Naja naja siamensis) produced increase motoneurone survival; no studies were carried out this agent beyond 10.