Fig. 5From: Perinatal testosterone exposure is critical for the development of the male-specific sexually dimorphic gastrin-releasing peptide system in the lumbosacral spinal cord that mediates erection and ejaculationSemi-quantitative analysis of the effects of the androgen surge on the developing spinal GRP system of males. Castrating rats at birth (ORX) decreased the number and intensity of GRP-immunoreactive neurons in the spinal cord during adulthood. These effects were prevented if the castrates were treated with testosterone propionate (ORX + TP) immediately after castration. Number of GRP neurons (a) and intensity of GRP-immunoreactive fibers (b) in the lumbosacral spinal cord. * P < 0.01 vs. control; †P < 0.01 vs. ORXBack to article page