Figure 8.

Spike frequency histograms from extracellular single-unit recording in the DRN 24 h after home-cage control (HC/HC) (A), home-cage control followed 24 h later by inescapable stress (HC/IS) (B), and escapable stress followed 24 h later by inescapable stress (ES/IS) (C). Midbrain slices were taken 24 h after final stress treatment, and 50 μm 5-HT was applied, followed by 150 nm ipsapirone. Mean percentage inhibition was calculated to account for the rate at which the cell reaches maximal ipsapirone-mediated inhibition.