Pro-cognitive activity induced in the rat by low doses of R-(+)-hyoscyamine.
In the passive-avoidance test R-(+)-hyoscyamine (10-100 microg kg(-1) i.p.) prevented amnesia induced by antimuscarinic treatment with AF-64A and benzhexol. The antiamnesic effect of R-(+)-hyoscyamine was comparable to that exerted by the cholinesterase inhibitor physostigmine (0.2 mg kg(-1) i.p) and the M(1) selective agonist AF-102B (10 mg kg(-1) i.p.). In the social learning test, R-(+)-hyoscyamine (10-100 microg kg(-1) i.p.) in adults rats, reduced the duration of active exploration of the familiar partner in the second session of the test similar to the nootropic drug piracetam (30 mg kg(-1) i.p.). These results demonstrated the ability of R-(+)-hyoscyamine to modulate memory functions and suggest that R-(+)-hyoscyamine could be useful in the treatment of cognitive deficits.
Department of Pharmacology, Viale G. Pieraccini 6, 1-50139, Florence, Italy.
C
C
Ghelardini
N
N
Galeotti
A
A
Bartolini
D000647:Amnesia / Q000517:prevention & control; D000818:Animals; D001285:Atropine / Q000008:administration & dosage / Q000494:pharmacology*; D001362:Avoidance Learning / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D007276:Injections, Intraventricular; D007536:Isomerism; D007858:Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D009043:Motor Activity / Q000187:drug effects; D018721:Muscarinic Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D010830:Physostigmine / Q000008:administration & dosage / Q000494:pharmacology; D008517:Phytotherapy; D010946:Plants, Medicinal; D011812:Quinuclidines / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013876:Thiophenes
D018721:Muscarinic Agonists; D011812:Quinuclidines; D013876:Thiophenes; D001285:Atropine; D010830:Physostigmine; C059240:cevimeline