Differential behavioral profile induced by the injection of dipotassium chlorazepate within brain areas that project to the nucleus accumbens septi.

LLANO LÓPEZ L.; CAIF.F; FRAILE M.; TINNIRELLO. B; LANDA A.; LAFUENTE, J.V; BAIARDI. G; GARGIULO, P. A.

PHARMACOLOGICAL REPORTS

POLISH ACAD SCIENCES INST PHARMACOLOGY

Año: 2013 vol. 65 p. 566 - 578

1734-1140

Background: The effect of the agonism on g-aminobutyric acid (GABA) receptors was studied within medial prefrontal cortex(mPFC), amygdala (AMY) and ventral hipocampus (VH) in the plus-maze test in male rats bilaterally cannulated. These structuressend glutamatergic projections to the nucleus accumbens septi (NAS), in which interaction and integration between these afferentpathways has been described. In a previous study of our group, blockade of glutamatergic transmission within NAS inducedan anxiolytic like effect.Methods: Three rat groups received either saline or dipotassium chlorazepate (1 or 2 μg/1 μl solution) 15 min before testing. Timespent in the open arms (TSOA), time per entry (TPE), extreme arrivals (EA), open and closed arms entries (OAE, CAE) and relationship between open- and closed-arms quotient (OCAQ) were recorded.Results: In theAMYinjected group TSOA, OAE and EAwere increased by the higher doses of dipotassium chlorazepate (p < 0.01).In the mPFC, TPE was decreased by both doses (p < 0.05). Injection within ventral hippocampus (VH) decreased TSOA, OAE andOCAQ with lower doses (p < 0.05). When the three studied saline groups were compared, TSOA, OAE, EA and OCAQ were enhancedin the VH group when compared to mPFC andAMY(p < 0.001). Insertion of inner canula (p < 0.001, p < 0.01, p < 0.01) andsaline injection showed an increasing significant difference (p < 0.001 in all cases) with the action of guide cannula alone within VHin TSOA, OAE and EA.Conclusion:We conclude that the injection of dipotassium chlorazepate has a differential effect depending of the brain area, leadingto facilitatory and inhibitory effects on anxiety processing.