Abstract
Involvement of both the serotonergic and the endogenous opioid systems in the onset of depressive behavior has been suggested. Previously we showed that serotonin (5-hydroxytryptamine) facilitates β-endorphin release in the nucleus accumbens (NAcc). Herein, the microdialysis method was used to assess in vivo the effects of serotonin on β-endorphin release in a rat model of depressive behavior (the Flinders sensitive line, FSL), before and after antidepressant treatment. The basal extracellular level of β-endorphin in the NAcc of FSL rats did not differ significantly from that in control rats. However, serotonin-induced β-endorphin release was impaired in FSL rats. Chronic treatment (18 days) with desipramine or paroxetine did not significantly affect the extracellular levels of β-endorphin in the NAcc of either the FSL or control rats. However, the chronic antidepressant treatment did normalize the serotonin-induced release of β-endorphin in FSL rats, as well as their behavioral manifestation of depressive behavior. Our results show that depressive behavior may relate to an impaired effect of serotonin on β-endorphin release in the NAcc in a rat model of depression, and suggest a possible new mode of action of antidepressant drugs.
| Original language | English |
|---|---|
| Pages (from-to) | 389-393 |
| Number of pages | 5 |
| Journal | Neuroscience |
| Volume | 110 |
| Issue number | 3 |
| DOIs | |
| State | Published - 20 Mar 2002 |
Bibliographical note
Funding Information:This study was in part funded by the National Institute of Psychobiology in Israel and the Israel Academy of Science and Humanities.
Keywords
- Depression
- Microdialysis
- Nucleus accumbens
- Serotonin
- β-endorphin