Fig. 6.

Synaptic convergence of terminals derived from different functional domains of the pallidal complex in the lateral hypothalamus adjacent to the entopeduncular nucleus. A, B, Low-power micrographs at two levels of a neuron in the lateral hypothalamus (LHn) that was apposed by four anterogradely labeled terminals. Three of the terminals (b_VP), the positions of which are indicated byarrows and the letters C, D, andE, are shown at higher magnification in C, D, and E, respectively. Each contains the BDHC reaction product (some granules of which are indicated by curved arrows) that was used to reveal the PHA-L transported from the ventral pallidum. The reaction product characteristically occupies only part of the labeled boutons. In each case the boutons form symmetrical synaptic contact (arrows) with the perikaryon (C, D) or the dendrite (d in E). The micrograph E is a serial section of that inB; the myelinated axon (ma) is indicated by an arrowhead in B. The fourth bouton (b_GP), the position of which is indicated byF in B, is shown at high magnification inF and contains the floccular DAB reaction product that adheres to membranes and occupies the whole of the labeled structure, identifying it as arising from the globus pallidus. This bouton also makes symmetrical synaptic contact (arrow) with the perikaryon of the lateral hypothalamic neuron. Glial cells (g) and a capillary (c) are labeled for correlation between the two low-power micrographs. Scale bars: A, B (shown in B), 10 μm;C–E (shown in E), 1 μm.