Department of Physiology, UCSF Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
Kenneth Kay
Department of Physiology, UCSF Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
Daniel F Liu
University of California, Berkeley, Berkeley, United States
Irene Grossrubatscher
University of California, Berkeley, Berkeley, United States
Adrianna Loback
Princeton University, Princeton, United States
Marielena Sosa
Department of Physiology, UCSF Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States
Jason E Chung
Department of Physiology, UCSF Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States
Mattias P Karlsson
Department of Physiology, UCSF Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States
Margaret C Larkin
Department of Physiology, UCSF Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States
Department of Physiology, UCSF Center for Integrative Neuroscience, University of California, San Francisco, San Francisco, United States; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States; Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, United States
While ongoing experience proceeds continuously, memories of past experience are often recalled as episodes with defined beginnings and ends. The neural mechanisms that lead to the formation of discrete episodes from the stream of neural activity patterns representing ongoing experience are unknown. To investigate these mechanisms, we recorded neural activity in the rat hippocampus and prefrontal cortex, structures critical for memory processes. We show that during spatial navigation, hippocampal CA1 place cells maintain a continuous spatial representation across different states of motion (movement and immobility). In contrast, during sharp-wave ripples (SWRs), when representations of experience are transiently reactivated from memory, movement- and immobility-associated activity patterns are most often reactivated separately. Concurrently, distinct hippocampal reactivations of movement- or immobility-associated representations are accompanied by distinct modulation patterns in prefrontal cortex. These findings demonstrate a continuous representation of ongoing experience can be separated into independently reactivated memory representations.
