Figure 6.

LHbMC host a distinct population of GABAergic neurons. (A, A_a) Confocal images showing the location of some GABA+ neurons (arrows) in combination with AVP and GluR1c immunofluorescence reaction, using high glutaraldehyde fixation. (A_b) An enlargement of one GABA positive neuron and its relation with the other two antigens. Notice that the antibody for GluR1c produced some nuclear background labeling. (A_c) Confocal image of 700 nm thickness of a dendritic segment of the cell (A_b)_. Notice that some labeled dendrites (green process) contained postsynaptic glutamate receptor type 1 (GluR1c, yellow points indicated by arrows) in juxtaposition to the AVP axon terminals (red process). (B,C) GABAergic neurons were mainly observed in lateral habenula medial central subnucleus (LHbMC) through immunoreaction against GABA and GAD65, respectively, in brain tissues posterior to 6 h of intra-habenular colchicine injection which enhanced GABA and GAD65 labeling (Ribak et al., 1978). The inset is for reference immunohistochemistry reaction of dentate gyrus (DG) of the same brain section. Notice the similarities of labeling patterns between DG GABAergic neurons (arrows in inset of B) and the habenular-labeling pattern (indicated by arrows in the inset of B_a). (C) Immunoreaction on the same brain tissue, using antibody against GAD65. (C_a) Magnification centered at the medio-central subnucleus of the lateral habenular complex, some labeled cells are indicated with white arrows. Scale bars: A: 100 μm; A_a: 20 μm; A_b: 10 μm; A_c: 1 μm; rest: 50 μm.