Samsoon Inayat, Brendan B McAllister, Bruce L McNaughton, Ian Q Whishaw, Majid H Mohajerani. Conjunctive and complementary CA1 hippocampal cell populations relate sensory events to immobility and locomotion. bioRxiv 2022.07.06.498996; doi: https://doi.org/10.1101/2022.07.06.498996

Abstract
“The way in which the brain decodes signals from sensory activity related to ongoing behavior has revolutionized the understanding of the function of neocortical areas and provides a blueprint to address allocortical regions such as the hippocampus. Here two-photon calcium imaging of somal activity in hippocampal CA1 neuron populations was done in head fixed mice given air or light stimulation when at rest or when moving on a conveyor belt. Air stimulation was also used to induce running for a fixed distance on the conveyor belt by releasing a conveyor belt brake. Overall, 99% of 2083 cells were active across 20 sensorimotor events with a larger proportion of cells active during locomotion. Nevertheless, for any sensorimotor event, only about 17% cells were active comprising of conjunctive (C ∈ A and B) cells shared among events and complementary (C ∈ A not B or C ∈ B not A) cells active in individual events. Conjunctive cells identified similar sensorimotor events representing stable representations of familiar experiences and complementary cells suggested recruitment of new cells for encoding novel experiences. The moment-to-moment recruitment of complementary and conjunctive cells with changing sensorimotor events signifies the involvement of hippocampus in functional networks integrating sensory information with ongoing movement. This role of hippocampus is well suited for movement guidance, spatial behavior, episodic learning and memory, context representation and scene construction.”

Samsoon Inayat, Brendan B McAllister, Bruce L McNaughton, Ian Q Whishaw, Majid H Mohajerani. Conjunctive and complementary CA1 hippocampal cell populations relate sensory events to immobility and locomotion. bioRxiv 2022.07.06.498996; doi: https://doi.org/10.1101/2022.07.06.498996