Time of day differences in the number of cytokine-, neurotrophin- and NeuN-immunoreactive cells in the rat somatosensory or visual cortex.

Sensory input to different cortical areas differentially varies across the light-dark cycle and likely is responsible, in part, for activity-dependent changes in time-of-day differences in protein expression such as Fos. In this study we investigate time-of-day differences between dark (just before light onset) and light (just before dark onset) for the number of immunoreactive (IR) neurons that stained for tumor necrosis factor alpha (TNFalpha), interleukin-1 beta (IL1 beta), nerve growth factor (NGF), the neuronal nuclear protein (NeuN) and Fos in the rat somatosensory cortex (Sctx) and visual cortex (Vctx). Additionally, astrocyte IL1 beta-IR in the Sctx and Vctx was determined.