Enhanced responses to muscarine in rats treated chronically with atropine.
Rats were treated for 14 or 30 days with 10 mg/kg sc atropine (AT) daily. 24 h after the last dose of At, 50 micrograms of muscarine (MU) was injected intracerebroventricularly (ivtr.). Long-term atropinization enhanced the behavior induced by MU. These data support our previous suggestion that chronic blockade of central muscarinic receptors induces their hypersensitivity.
D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects*; D004357:Drug Synergism; D007276:Injections, Intraventricular; D008297:Male; D009116:Muscarine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D001285:Atropine; D009116:Muscarine