Comparable activity levels in developmentally deprived and non-deprived layer IV cortical columns of the adult rat primary somatosensory cortex.

It has been suggested that evoked neural activity levels promote the selective construction of the primary somatosensory cortex (S1) neuropil. Sensory deprivation after S1 formation has, however, no effects on its postnatal growth. This indicates that S1 neuropil elaboration is independent from the ongoing levels of evoked cortical activity, and/or that sensory deprivation does not reduce overall levels of S1 evoked activity. We thus indirectly evaluated chronic and acute levels of neural activity in the developmentally, sensory deprived adult S1. Relative succinic dehydrogenase activity and 3H2-deoxyglucose uptake were comparable in control and deprived barrels. Our observations support the idea that normal levels of evoked neural activity prevent atrophic changes in the developmentally deprived adult S1. They can not rule out, however, that early selective S1 neuropil construction occurs independent from evoked neural activity levels.