Neuroscience 2000 Abstract
| Presentation Number: | 433.12 |
|---|---|
| Abstract Title: | Amplifying noradrenergic activation by stress elicits a galanin-mediated anxiolytic response in central amygdala opposing the anxiogenic effects of norepinephrine. |
| Authors: |
Khoshbouei, H.*1
; Cecchi, M.1
; Morilak, D. A.1
1Pharmacology, UT Hlth Sci Ctr, San Antonio, TX |
| Primary Theme and Topics |
D. Neurotransmitters, Modulators, Transporters, and Receptors - 48. Peptides |
| Secondary Theme and Topics | D. Neurotransmitters, Modulators, Transporters, and Receptors<br />- 57. Interactions between neurotransmitters |
| Session: |
433. Peptides: physiology II Poster |
| Presentation Time: | Tuesday, November 7, 2000 11:00 AM-12:00 PM |
| Location: | Hall G-J |
| Keywords: | neuropeptides, anxiety, extended amygdala, galanin |
Activation of the noradrenergic system contributes to stress-induced anxiety on the elevated plus maze (Cecchi, SFN 2000). We have also demonstrated, however, that pretreatment with the anxiogenic adrenergic autoreceptor antagonist yohimbine induces a paradoxical anxiolytic response to stress (Khoshbouei, SFN 1999). We hypothesize that this is due to release of galanin in the central amygdala (CeA), induced by amplifying stress-activation of the noradrenergic system. We thus investigated the role of galanin in CeA in modulating stress-induced anxiety after amplifying the noradrenergic response with yohimbine. Male Sprague-Dawley rats were pretreated with vehicle or yohimbine (2.5 mg/kg, i.p.) 20 min before bilateral microinjections into CeA of vehicle, the galanin antagonist M40 [1 or 4 nmole/0.2 ul], galanin [1 nmole] or M40 followed by galanin. After microinjections, controls were returned to their cage, while stressed rats were exposed to 5 min immobilization stress then 15 min recovery before plus maze testing. Stress was anxiogenic, but yohimbine pretreatment before stress induced a significant anxiolytic response compared to stress alone. This anxiolytic effect was mimicked by galanin injected into CeA before stress. M40 dose-dependently blocked the anxiolytic effect of yohimbine pretreatment, resulting in an anxiogenic response similar to that of stress alone, and M40 also blocked the anxiolytic effect of galanin (all n=8-16, p<0.05). These results suggest that amplifying noradrenergic activation by stress recruits galanin release in CeA, which acts as a buffer to oppose the anxiogenic effects of NE.
Supported by NIMH 53851
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2000 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2000. Online.
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