Link to bioRxiv paper: http://biorxiv.org/cgi/content/short/2020.06.19.162446v1?rss=1 Authors: Roussy, M., Luna, R., Duong, L., Corrigan, B., Gulli, R. A., Nogueira, R., Moreno-Bote, R., Sachs, A. J., Palaniyappan, L., Martinez-Trujillo, J. C. Abstract: The primate lateral prefrontal cortex (LPFC) is considered fundamental for temporarily maintaining and manipulating mental representations that serve behavior, a cognitive 1 function known as working memory . Studies in non-human primates have shown that LPFC lesions impair working memory2 and that LPFC neuronal activity encodes working 3 memory representations . However, such studies have used simple displays and constrained gaze while subjects held information in working memory3, which put into 4,5 question their ethological validity . Currently, it remains unclear whether LPFC microcircuits can support working memory function during natural behavior. We tested macaque monkeys in a working memory navigation task in a life-like virtual environment while their gaze was unconstrained. We show that LPFC neuronal populations robustly encode working memory representations in these conditions. Furthermore, low doses of the NMDA receptor antagonist, ketamine, impaired working memory performance while Science,NewYorkUniversity,NewYork,NY,USA. CenterforBrainandCognition,and Psychiatry, the University of Western Ontario, London, ON, Canada. 11 London, ON, Canada Lawson Health Research Institute, London, ON, Canada. Brain and Mind Institute, the University of Western Ontario, 1 sparing perceptual and motor skills. Ketamine decreased the firing of narrow spiking inhibitory interneurons and increased the firing of broad spiking cells reducing population decoding accuracy for remembered locations. Our results show that primate LPFC generates robust neural codes for working memory in naturalistic settings and that such codes rely upon a fine balance between the activation of excitatory and inhibitory neurons. Copy rights belong to original authors. Visit the link for more info