Figure 3.
Activated afferents of LH during renewal of alcoholic beer seeking. A, Mean (±SEM) responses on the active (closed squares) and inactive (open squares) nose poke during extinction (left) and test (right). Rats were trained in context A, extinguished in context B, and then tested in either context A (group ABA) or context B (group ABB). Return to the original training context after extinction resulted in renewal. B, C, Fluorescent photomicrographs of representative injection sites of 40 nL of the retrograde tracer CTb in either the LH (B) or PeF (C). Scale bars, 200 μm. D, E, Photomicrographs of representative CTb-IR in the nucleus accumbens after injections of CTb in either the LH (D) or PeF (E). Scale bars, 200 μm. D, Arrowheads point to c-Fos-IR/CTb-IR cells found in the dorsomedial shell in ABB rats (top inset) and c-Fos-IR/CTb-IR cells found in the ventral shell in ABA rats after LH CTb injection (bottom inset). E, Top and bottom insets show c-Fos-IR only and CTb-IR only cells in the dorsomedial (top) and ventral (bottom) shell found in ABA rats after PeF CTb injection. Scale bars (for insets), 20 μm. F, Effect of renewal of alcoholic beer seeking on c-Fos-IR in the dorsomedial and ventral shell. Bars show the mean (±SEM) total number of c-Fos-IR cells (left), single labeled c-Fos-IR cells (middle), and c-Fos-IR/CTb-IR-labeled cells (right). A specific induction of c-Fos that was associated with ABA renewal was detected in the ventral shell. There was a specific induction of c-Fos in LH-projecting cells associated with ABA renewal in the ventral shell. In the dorsomedial shell there was a specific induction of c-Fos in LH-projecting cells in ABB rats. Induction of c-Fos in PeF-projecting cells was rare. *p < 0.05 comparing total c-Fos cells in the ventral shell for ABA with ABB (left), non-CTb-IR c-Fos cells in the ventral shell for ABA with ABB (middle), and total double-labeled cells in the ventral shell for ABA with ABB (right); +p < 0.05 comparing total double-labeled cells in the dorsomedial shell for ABA with ABB after CTb injection into LH (right).