Subcortical modulation of hippocampal activity, multichannel recordings in head-restrained, behaving mice

Cortical circuits display different functional states under the influence of subcortical modulatory input. In our study we aimed to uncover fundamental aspects of this subcortical modulation by focusing on the effect of the median raphe nucleus on the hippocampal network. High channel count electrophysiological recordings were executed from dorsal hippocampus, along with the measurement of neuronal activity in the median raphe, in head-restrained, awake mice. The different cell types of the MR (vGAT, vGlut2, vGlut3) were optogenetically identified and multimodal sensory stimuli were applied to the mouse while monitoring both subcortical activity in the MR and activity in the dorsal CA1 region. These data allow us to characterize the properties of hippocampal neurons in the intact animal and how these properties are changed by subcortical inputs thus providing important constraints for network models of the hippocampus.