Pulvinar perturbation causes functional reorganization of visual attentional information in posterior parietal cortex

The pulvinar nucleus of the thalamus (PUL) is a higher-order thalamic relay and the main visual extrageniculate thalamic nucleus. Evidence suggests the PUL coordinates information processing across cortical areas involved in visual perception and attention. Other findings suggest the PUL may also influence higher-order cognitive processes, such as attentional control, through interactions with connected neocortical areas like the posterior parietal cortex (PPC). We hypothesized that PUL input to the dorsal and caudal PPC (DPPC and CPPC) enhances visuospatial processing and attention. To test this hypothesis, we recorded neuronal activity in the PUL, DPPC, and CPPC of freely behaving rats performing the visuospatial attention (VSA) task while optogenetically suppressing PUL neurons on some trials. We found that PUL manipulation did not affect behavioral performance, but reorganized neural codes in DPPC and CPPC as well as PUL itself.