Tonic modulation of anxiety-like behavior by corticotropin-releasing factor (CRF) type 1 receptor (CRF1) within the medial prefrontal cortex (mPFC) in male mice: role of protein kinase A (PKA).
Horm Behav 2014;
66:247-56. [PMID:
24848364 DOI:
10.1016/j.yhbeh.2014.05.003]
[Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 05/03/2014] [Accepted: 05/07/2014] [Indexed: 01/01/2023]
Abstract
The medial prefrontal cortex (mPFC) and the neuropeptide corticotropin-releasing factor (CRF) have recently been receiving more attention from those interested in the neurobiology of anxiety. Here, we investigated the CRF pathway in the modulation of anxiety-like behaviors in male mice exposed to the elevated plus-maze (EPM), through intra-mPFC injections of CRF, CP376395 [N-(1-ethylpropyl)-3,6-dimethyl-2-(2,4,6-trimethylphenoxy)-4-pyridinamine hydrochloride, a CRF type 1 receptor antagonist (CR F1)] or H-89 [N-[2-[[3-(4-bromophenyl)-2-propenyl]amino]ethyl]-5-isoquinolinesulfonamide dihydrochloride, a protein kinase (PKA) inhibitor]. We also investigated the effects of intra-mPFC injections of H-89 on the behavioral effects induced by CRF. Mice received bilateral intra-mPFC injections of CRF (0, 37.5, 75 or 150pmol), CP376395 (0, 0.75, 1.5 or 3nmol) or H-89 (0, 1.25, 2.5 or 5nmol) and were exposed to the EPM, to record conventional and complementary measures of anxiety for 5min. Results showed that while CRF (75 and 150pmol) produced an anxiogenic-like effect, CP376395 (all doses) and H-89 (5nmol) attenuated anxiety-like behavior. When injected before CRF (150pmol), intra-mPFC H-89 (2.5nmol, a dose devoid of intrinsic effects on anxiety) completely blocked the anxiogenic-like effects of CRF. These results suggest that (i) CRF plays a tonic anxiogenic-like role at CRF1 receptors within the mPFC, since their blockade per se attenuated anxiety indices and (ii) the anxiogenic-like effects following CRF1 receptor activation depend on cAMP/PKA cascade activation in this limbic forebrain area.
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