Fig. 3.

Effects of dark-rearing or brief binocular activity blockade on BDNF mRNA levels in the lateral geniculate nucleus. Cresyl violet-counterstained coronal sections from an unmanipulated P45 animal (a), an animal that received binocular sodium citrate injections on P43 and was examined at P45 (c), an animal that received binocular TTX injections on P43 and was examined at P45 (e), or an animal that was dark-reared from birth to P45 (g). b, d,f, h, Dark-field photomicrographs ofin situ hybridization for BDNF mRNA on sections adjacent to those in a, c, e,g. A clear reduction in BDNF mRNA expression is detectable after TTX treatment (f) but not after dark-rearing (h). Medial is to theleft and dorsal is up. A,A1, and C denote LGN laminae. Scale bar, 500 μm.