Skip to main content
. 2008 Jan 9;28(2):529–542. doi: 10.1523/JNEUROSCI.2666-07.2008

Figure 2.

Figure 2.

Depression of excitatory transmission at putative BLA–mPFC synapse mediated by the D1-like (D1/5) agonist SKF is enhanced through activation of CRF1 receptors in saline-treated control rats, whereas neither r/hCRF itself nor CRF antagonists affect evoked EPSCs. A, Representative traces of putative BLA–mPFC EPSCs at baseline and after increasing concentrations of SKF (top traces) and SKF plus 50 nm r/hCRF (bottom traces). Concentration–response curves for each treatment group are shown below. SKF (1 and 10 μm) significantly depressed EPSCs. Combining r/hCRF (50 nm) plus SKF (10 nm or higher concentrations) further depressed EPSCs, indicating that r/hCRF (50 nm) facilitated SKF effects at this putative BLA–mPFC synapse. B, Bar graph depicts changes in putative BLA–mPFC EPSC amplitudes at two different concentrations of SKF (1, 10 μm) alone and in combination with r/hCRF (50 nm) in the presence of selective antagonists for D1/5 or CRF1 receptors. Shown are SKF (1 μm, 10 μm) alone and in the presence of SCH, a selective D1/5 receptor antagonist, and SKF (1 μm, 10 μm) and r/hCRF (50 nm) together and with NBI, a selective CRF1 receptor antagonist. SCH (10 μm) prevented SKF-induced depression of EPSCs [1 μm SKF plus SCH, 101.4 ± 3.4%; 10 μm SKF plus SCH, 101.2 ± 3.3%; p > 0.05 compared with baseline; p < 0.05 compared with SKF (1, 10 μm) alone]. NBI (500 nm) blocked r/hCRF (50 nm)-mediated facilitation of SKF effects [1 μm SKF plus r/hCRF plus NBI, 87.4 ± 1.1%; 10 μm SKF plus r/hCRF plus NBI, 74.6 ± 4.2%; p < 0.05 compared with baseline; p < 0.05 compared with SKF (1, 10 μm) plus r/hCRF (50 nm)]. There were no significant differences (p > 0.05) between EPSC values after SKF (1, 10 μm) compared with SKF (1, 10 μm) plus r/hCRF (50 nm) in the presence of NBI. Ast2B, a specific CRF2 antagonist, did not affect EPSCs in saline-treated/control rats. C, Left, Bar graphs summarizing lack of effects of different r/hCRF concentrations on EPSCs. Neither NBI (500 nm; center) nor Ast2B (200 nm; right) had any significant effects on EPSCs before or after washout.