Examining the effects of PKMzeta Inhibition on Primary Sensory (S1) cortex in Rat and Non-Human Primate.

Abstract

The primary somatosensory cortex (S1) is organized in a somatotopic manner. It has previously been demonstrated that responses to localized stimuli, termed a cortical response field (CRF) are characterized by a central excitatory response surrounded by a border of local inhibition. The size and shape of these CRFs can change, sometimes rapidly, as a result of behavioral training or chronic changes in sensory input. It has been hypothesized that mechanisms of synaptic plasticity, such as long-term potentiation (LTP) may play an important role in developing and maintaining the structure of a CRF. In this study we injected Zeta Inhibitory Peptide (ZIP), an inhibitor of the protein kinase PKMz known to be involved in the maintenance of LTP, into the primary sensory cortex (S1) of both rodents and non-human primates. We found that administration of ZIP caused a simultaneous disruption of CRF boundaries as well as a net decrease in response to tactile stimulation in both species. The evidence from these studies supports a model of sensory cortex that includes ongoing maintenance of CRF borders via PKMz dependent LTP.