Intermittent and continuous swim stress-induced behavioral depression: sensitivity to norepinephrine- and serotonin-selective antidepressants.
BACKGROUND
Intermittent swim stress (ISS) produces deficits in swim escape learning and increases immobility in the forced swim test (FST). A previous attempt to reverse this immobility with the selective serotonin reuptake inhibitor (SSRI), fluoxetine (FLX), was unsuccessful, but the sensitivity of this immobility to other types of antidepressants is unknown.


OBJECTIVE
In experiment 1, we evaluate the ability of the norepinephrine (NE) selective reuptake inhibitor (NSRI), desipramine (DES), to reverse the ISS-induced immobility in the FST compared to confined controls (CC), while in experiment 2, we test the efficacy of either the SSRI or NSRI to reverse the immobility produced by either ISS or continuous swim (CS)/FST.


METHODS
Rats were exposed to their respective behavioral pretreatment (ISS, CS/FST, or CC) and were then injected with an antidepressant or saline solution 23.5, 5, and 1 h prior to the FST.


RESULTS
In experiment 1, DES reduced immobility and increased the climbing behavior in the ISS group without altering these behaviors in the CC, while in experiment 2, the CS/FST-induced immobility was reduced by both antidepressants (i.e., FLX and DES), while the ISS-induced immobility was only affected by DES.


CONCLUSIONS
These results suggest that the ISS-induced immobility is mediated through the NE system and may represent a model for atypical depression.
Drugan
Robert C
RC
Department of Psychology, University of New Hampshire, Durham, 03824-3567, USA. rcdrugan@unh.edu
Macomber
Heather
H
Warner
Timothy A
TA
D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology*; D000818:Animals; D018687:Antidepressive Agents, Second-Generation / Q000494:pharmacology; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology; D003863:Depression / Q000188:drug therapy; D003891:Desipramine / Q000494:pharmacology*; D004195:Disease Models, Animal; D005473:Fluoxetine / Q000494:pharmacology*; D007103:Immobilization; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D013315:Stress, Psychological / Q000188:drug therapy; D013550:Swimming; D013997:Time Factors
D018759:Adrenergic Uptake Inhibitors; D018687:Antidepressive Agents, Second-Generation; D000929:Antidepressive Agents, Tricyclic; D003891:Desipramine; D005473:Fluoxetine; D017367:Selective Serotonin Reuptake Inhibitors