Intracerebroventricular administration of antisense oligonucleotide directed against TGF-β1 increased the density of apoptotic cells in the dentate gyrus after five days of ADX. The ASO, SCRO (10 μg/day) or vehicle were stereotaxically delivered into the lateral left ventricle, via a cannula connected to a subcutaneously implanted Alzet osmotic mini-pump, delivering the corresponding solution during 7 days. The animals were adrenalectomized, or sham-operated 2 days after the beginning of the i.c.v. treatment and euthanized 5 days after. Photomicrographs illustrate changes in apoptotic morphology in the suprapyramidal layer of the DG of: (A) control (saline-treated, sham-operated), (B) saline-treated, adrenalectomized (ADX-5), and (C) ASO TGF-β1-treated, adrenalectomized (ADX-5/TGF-β1 ASO) animals. Arrowheads denote pyknotic nuclei, nuclei containing clumped chromatin disassembling and degenerating nuclei. Scale bar = 20 μm.