Impaired performance of rats in the Morris swim-maize test late in abstinence following long-term sodium barbital treatment.
Rats were tested for place learning in the Morris swim maze on days 110-114 of abstinence following 48 weeks of treatment with sodium barbital. A retarded acquisition of the swim-maze task, that could not be ascribed to motor impairments, was found in the barbital-treated rats. There was a significant difference in brain weight, but there were no significant differences between the control and barbital-treated rats in the frontal cortical concentrations of noradrenaline (NA), dopamine (DA), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA), nor in the intra- and extrasynaptosomal activities of cerebral cortical monoamine oxidase towards NA and 5-HT. Postsynaptically, neither the cerebral cortical inositol phospholipid breakdown responses to carbachol and NA (mediated by muscarinic and alpha 1-adrenergic receptors, respectively), nor the striatal and cortical densities of muscarinic receptors labelled by [3H]quinuclidinyl benzilate [( 3H]QNB) were found significantly to be altered in the barbital-treated rats. A strong correlation between the density of striatal and cortical [3H]QNB binding sites was seen for the barbital-treated (r = 0.91) but not for the control (r = -0.05) rats. It is suggested that the deficit in performance of the barbital-treated rats in the Morris maze may be related to a cholinergic dysfunction.
Department of Pharmacology, University of Umeå, Sweden.
A K
AK
Mohammed
G
G
Wahlström
G
G
Tiger
P E
PE
Björklund
A
A
Stenström
O
O
Magnusson
T
T
Archer
C J
CJ
Fowler
A
A
Nordberg
D000818:Animals; D001462:Barbital / Q000008:administration & dosage*; D001463:Barbiturates / Q000008:administration & dosage*; D001679:Biogenic Amines / Q000378:metabolism; D001923:Brain Chemistry / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology; D007295:Inositol Phosphates / Q000494:pharmacology; D008297:Male; D008995:Monoamine Oxidase / Q000378:metabolism; D009638:Norepinephrine / Q000494:pharmacology; D011597:Psychomotor Performance / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology*; D013550:Swimming; D013997:Time Factors
D001463:Barbiturates; D001679:Biogenic Amines; D007295:Inositol Phosphates; D001462:Barbital; D002217:Carbachol; D008995:Monoamine Oxidase; D009638:Norepinephrine