Modification of behavioral response to intra-hippocampal injections of noradrenaline and adrenoceptor agonists by chronic treatment with desipramine and citalopram: functional aspects of adaptive receptor changes.
The present study investigated the effects of acute and of chronic treatment with desipramine (DI) and citalopram (CT) on the alterations in rat behavior in the open field and in the forced swim tests produced by intra-hippocampal microinjections of noradrenaline (NA) and adrenoceptor agonists. Chronic but not acute treatment with DI potentiated the stimulatory effects of NA on the rats' behavior in the open field test and in the forced swim test as well as revealed the excitatory effect of microinjections of phenylephrine at a dose producing insignificant changes when given alone. The depressive effects of clonidine in the open field test were antagonized by acute DI administration and reversed by chronic DI. No characteristic changes in the isoproterenol-induced increase in rat locomotion were observed following chronic DI since the antagonistic interaction was found after both acute and chronic DI pretreatment. Chronic though not acute administration of CT produced effects in the forced swim test similar to those of DI, i.e. excitatory effects of phenylephrine and clonidine on behavior. The data indicate a potentiation of excitatory processes in the brain limbic structure, probably mediated via alpha 1-adrenoceptors.
D000220:Adaptation, Biological; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D015283:Citalopram; D003891:Desipramine / Q000494:pharmacology*; D005106:Exploratory Behavior / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects*; D008297:Male; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects; D009638:Norepinephrine / Q000037:antagonists & inhibitors*; D011437:Propylamines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*; D013566:Sympathomimetics / Q000037:antagonists & inhibitors*; D013997:Time Factors
D011437:Propylamines; D011941:Receptors, Adrenergic; D013566:Sympathomimetics; D015283:Citalopram; D003891:Desipramine; D009638:Norepinephrine