Avoidance learning during antidepressant withdrawal in mice.
Shuttle-box avoidance acquisition, locomotor activity and density of adrenoreceptors in the cerebral cortex have been evaluated, in CD-1 mice, during withdrawal from repeated treatment with desipramine or mianserin (5 or 14 daily injections of antidepressant drug, 10 mg kg-1). Withdrawal from mianserin did not produce any behavioural or neurochemical change. Mice withdrawn from desipramine exhibited avoidance facilitation, when training started 24 h (but not 72 or 120 h) after the last injection. Locomotor activity was not affected and no change was found in the density of beta-adrenoreceptors. An up-regulation of alpha 2- and, to a lesser extent, of alpha 1-adrenoreceptors, occurred 72 h following desipramine withdrawal. However, the assessment of the role played by these neurochemical changes in the avoidance facilitation observed during withdrawal from the antidepressant treatment requires further study.
Istituto di Psicobiologia e Psicofarmacologia, CNR, Roma, Italy.
M
M
Sansone
M
M
Battaglia
J
J
Ekblom
I
I
Nalepa
J
J
Vetulani
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects*; D001921:Brain / Q000187:drug effects; D003891:Desipramine / Q000009:adverse effects*; D007274:Injections, Intraperitoneal; D008297:Male; D008803:Mianserin / Q000009:adverse effects*; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D013375:Substance Withdrawal Syndrome
D008803:Mianserin; D003891:Desipramine