Similarities between the akinesia induced by carbachol microinjections into the pontine reticular formation and neuroleptic catalepsy.
We reported previously that microinjections of carbachol directly into the pontine reticular formation of rats induced intense akinesia. In the present article we report results of tests for rigidity, righting, bracing and clinging which were conducted with the purpose to characterize behaviorally this type of akinesia. After injections of 5-15 micrograms/0.5 microliter of carbachol into the pontine reticular formation the rats were cataleptic, were not rigid when equilibrium was not challenged, had strong righting reflexes and strong bracing and clinging responses. This type of akinesia is different from the catatonia induced by systemic morphine (20 mg/kg IP), but similar to the catalepsy induced by systemic injections of haloperidol (5 mg/kg IP). It is thus suggested that the cataleptic state produced by topical carbachol in the pons is related to the dopaminergic mechanisms important for the cataleptic effect of the neuroleptic drugs.
Elazar
Z
Z
Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Paz
M
M
D000704:Analysis of Variance; D000818:Animals; D002217:Carbachol / Q000008:administration & dosage / Q000494:pharmacology*; D002375:Catalepsy / Q000139:chemically induced*; D006220:Haloperidol / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008845:Microinjections / Q000379:methods; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009043:Motor Activity / Q000187:drug effects*; D011149:Pons; D051381:Rats; D012154:Reticular Formation
D009020:Morphine; D002217:Carbachol; D006220:Haloperidol