Katrina working in the NAC lab under the guidance of Dr. Victoria Templer.
A holistic understanding of the posterior parietal cortex (PPC) cannot be obtained until its role is evaluated in non-primate species. For this research project, we look to define the boundaries of the PPC within rat models. The PPC is a region essential for attention, including the selection of sensory information based on previous knowledge and goals (top-down processing) and presented stimuli that are deemed behaviorally relevant (bottom-up processing). The overall goal of this research is to strengthen the previous findings on the structure and function of the PPC, its role in attentional processing, and how it functions in relation to other associative structures. This project will be divided into two specific aims. Aim 1 looks to evaluate PPC's contribution in top-down and bottom-up processing. We hypothesize that the PPC does support both processes and that the PPC is involved in spatial memory and social information. Based on our hypotheses, we predict that rats with damage to the PPC will show impairment on the challenge aspects of the 5 Choice Serial Reaction Task and in object-location memory, as well as social recognition. Specific Aim 2 looks to dissociate functions within subdivisions of the PPC including dorsal and caudal regions previously defined in primate literature. We hypothesize that similarly to primate neuroscience, the rat dorsal PPC (dPPC) will be more associated with top-down processing and that the caudal PPC (cPPC) will be more associated with bottom-up processing. Based on our hypotheses, we predict that the dPPC-lesioned group will show difficulty in the 5CSRT challenges that involve top-down challenges, and the opposite for the cPPC-lesioned rats. We also predict that the dPPC will show difficulty in spatial object-location memory and social recognition, and no impairment in standard object recognition for both cPPC and dPPC groups. The use of top-down processing that guides memory retrieval, decision making, and other attentional functions in humans are often disrupted in many neurological disorders and could benefit from research on animals models. By mapping the function of PPC, we are able to introduce more translational research regarding the PPC and memory processes.