Figure 2.

Cell proliferation in the hippocampal dentate gyrus of the tree shrew was quantified with the use of BrdUrd immunohistochemistry. (A) A representative photomicrographs of a Control animal. The majority of proliferating cells was found dominantly in the subgranular zone defined as a two-cell-body-wide zone between the granule cell layer (gcl) and hilus (h). Positively labeled cells generally occurred singly or in small clusters comprised of three to five cells. Scale bar = 100 μm. (B) Chronic psychosocial stress significantly suppressed cell proliferation in the hippocampal dentate gyrus (Stress), whereas chronic tianeptine treatment reversed the stress-induced effect (Stress + Tianeptine). Antidepressant treatment alone had an insignificant effect on hippocampal cell proliferation (Control + Tianeptine). Results are given as mean ± SEM number of BrdUrd-positive cells in the hippocampal dentate gyrus. *, P < 0.05 vs. Controls.