In Vivo Characterization of Neurophysiological Diversity in the Lateral Supramammillary Nucleus during Hippocampal Sharp-wave Ripples of Adult Rats

Ana F Vicente (1, 2) , Andrea Slézia (1, 2) , Antoine Ghestem (1, 2) , Christophe Bernard (1, 2) , Pascale P. Quilichini (1, 2)

1 INS - Institut de Neurosciences des Systèmes
2 AMU - Aix Marseille Université

The extent of the networks that control the genesis and modulation of hippocampal sharp-wave ripples (SPW-Rs), which are involved in memory consolidation, remains incompletely understood. Here, we performed a detailed in vivo analysis of single cell firing in the lateral supramammillary nucleus (lSuM) during theta and slow oscillations, including SPW-Rs, in anesthetized rats. We classified neurons as SPW-R-active and SPW-R unchanged according to whether or not they increased their firing during SPW-Rs. We show that lSuM SPW-R active neurons increase their firing prior to SPW-Rs peak power and prior to hippocampal excitatory cell activation. Moreover, lSuM SPW-R-active neurons show increased firing activity during theta and slow oscillations as compared to unchanged neurons. These results suggest that a sub-population of lSuM neurons can interact with the hippocampus during SPW-Rs, raising the possibility that the lSuM may modulate memory consolidation.

Keywords: SPW-Rs; sharpwave ripples; standard deviation; supramammillary nucleus; THETA; theta oscillations hippocampus; sharp-wave ripple; firing; theta; slow oscillation; confidence interval; dentate gyrus; hippocampus; local field potential; lSuM; lateral supramammillary nucleus; slow oscillations

Domains: Life Sciences [q-bio]

Ana F Vicente, Andrea Slézia, Antoine Ghestem, Christophe Bernard, Pascale P. Quilichini. In Vivo Characterization of Neurophysiological Diversity in the Lateral Supramammillary Nucleus during Hippocampal Sharp-wave Ripples of Adult Rats. Neuroscience, 2020, 435, pp.95 - 111. ⟨10.1016/j.neuroscience.2020.03.034⟩. ⟨hal-03626492⟩