Time-dependent changes in c-fos and zif268 expression in primary and higher order visual areas of the adult retinal lesion cat (Felis catus)

The adult mammalian brain retains the capacity to exhibit plasticity-mediated adjustments in response to changes in sensory input. Induction of focal retinal lesions in both eyes can lead to cortical map reorganization in the visual cortex of adult cats. This plasticity-mediated reorganization is known to be associated with time-dependent modifications in neuronal activity in primary visual cortex. In fact most investigations are confined to primary visual area 17, as a consequence there is not much known about the impact of the retinal lesions on higher order visual areas. We have examined the activity changes in primary visual area 17 as well as five higher order visual areas to broaden our knowledge regarding intra-cortical and inter-cortical reactivation dynamics. By means of real-time PCR for the immediate early genes zif268 and c-fos we have registered the spatio-temporal molecular activity patterns in areas 17, 18, 19, posterior medial lateral suprasylvian area (PMLS), 21a and 7. We have demonstrated that central retinal lesions elicit alterations over the full extent of every visual area. Interestingly, our data strongly indicate that hyperactivity occurs in the motion perception-related area PMLS but not in the form perception-associated area 21a. In conclusion, we propose that intra-cortical as well as inter-cortical influences are at play in functional cortical remapping upon sensory deprivation.status: publishe