Thalamic ensemble activity during distinct behaviors

The posterior medial nucleus (POm) of the thalamus represents a higher-order thalamic nucleus characterized by its reciprocal connections with the primary somatosensory cortex (S1). It exhibits intricate projections to and from motor, premotor, association cortices, and the brainstem. Owing to its distinct firing characteristics and multifaced connectivity profiles, various functions ranging from maintaining arousal to higher somatosensory processing have been attributed to it. To address functional features of the mouse POm, we image relay neuron activity in freely moving mice while they perform different behaviors. We hypothesize that ensemble activity coinciding with distinct behavioral episodes will reveal functional contributions of the POm to these behaviors. Deep imaging is achieved by implanting GRIN lenses at GCaMP-expressing POm in conjunction with UCLA miniscopes. We reliably record robust signals emanating from ensembles of POm relay neurons. We correlate activity patterns and the identity of active neurons in diverse behavioral paradigms encompassing locomotion, sensory stimulation, and salience detection. Furthermore, behavioral states are manipulated by using optogenetics and other techniques. Distinct neural ensembles were delineated and categorized according to their patterns of firing activity observed across various phases of behavioral experiments conducted across multiple sessions and tasks.