Differences in cholinergic agonist- and cholinergic antagonist-induced changes in avoidance responses between dd mice...

Effects of pilocarpine (PILO), physostigmine (PHYSO), atropine (AT) and scopolamine (SCOP) on continuous (response-shock interval = 30 sec and shock-shock interval = 5 sec) and discrete (intertrial interval = 25 sec and warning duration = 5 sec) lever-press avoidance responses in dd strain mice and Wistar strain rats were investigated. PILO and PHYSO suppressed continuous and discrete avoidance responses in both the mice and rats. However, the mice tended to show more sensitivity than the rats to the avoidance-suppressing effect of PILO and PHYSO. AT and SCOP suppressed the avoidance responses in the mice, but facilitated them in the rats. These results suggest that the neural activities of the central muscarinic-cholinergic systems are different between dd mice and Wistar rats.