Neuroscience 2005 Abstract
| Presentation Number: | 108.14 |
|---|---|
| Abstract Title: | Chronic desipramine attenuates forced swim test immobility induced by long-term light deprivation in rats. |
| Authors: |
Gonzalez, M. M. C.*1
; Aston-Jones, G.1
1Dept. Psychiatry, Lab. of Neuromodulation and Behavior, Univ. of Pennsylvania, Philadelphia, PA |
| Primary Theme and Topics |
Disorders of the Nervous System - Cognitive, Emotional and Behavioral State Disorders -- Affective disorders: Animal models |
| Secondary Theme and Topics | Homeostatic and Neuroendocrine Systems<br />- Biological Rhythms and Sleep<br />-- Seasonality |
| Session: |
108. Animal Models of Depression: Monoamines Poster |
| Presentation Time: | Saturday, November 12, 2005 2:00 PM-3:00 PM |
| Location: | Washington Convention Center - Hall A-C, Board # UU85 |
| Keywords: | depression, animal model, antidepressant, monoamine |
Previously we showed that rats in long-term constant darkness (DD) exhibit anatomical and behavioral features associated with depression, including decreased norepinephrine (NE) and serotonin (5-HT) innervation of frontal cortex, hypersomnia during the active period, and increased immobility in the forced swim test (FST). We proposed that such light deprivation is a potential environmental factor that could trigger depression by impairing, at least in part, the NE/5-HT systems (Gonzalez and Aston-Jones, SFN 2004). Here, we seek to test this hypothesis by attempting to reverse the depression-like behavior by chronic treatment with the antidepressant desipramine (DMI). Pairs of cages of individually housed adult Sprague-Dawley male rats (200-250 g) were placed together in an environmentally controlled compartment (23±1°C) with free access to food and water. During six weeks, the animals were kept in DD. Subsequently, DMI (~30 mg/kg, along with 0.02% saccharin to increase palatability) was administered in drinking water for 24 days. Control animals were given tap water. At the end of the antidepressant treatment, animals were submitted to a FST to evaluate behavioral symptoms of depression. DMI-treated DD animals showed 74% less immobilization than the non-treated DD group [37.29 ± 8.58 vs. 145.3 ± 29.79 sec, t (6)= 3.484, P< 0.01, n = 4 for each group]. The antidepressant-like effect of DMI on this behavioral test supports the hypothesis that long-term light deprivation is an animal model of depression. Our present results lead us to propose that light deprivation-associated impairment of NE locus coeruleus and 5HT raphe systems could be part of the etiology for depression, and in particular seasonal affective disorder (SAD). Light stimulation may be required for the maintenance of proper functioning of NE locus coeruleus and 5-HT raphe systems, and for their related behavioral and mental processes (i.e. sleep, mood).
Supported by a Young Investigator Award from NARSAD and PHS grant R01 NS24698
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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