SPIKING ACTIVITY CORRELATES WITH THE BEHAVIOUR IN THE POSTERIOR STRIATUM OF AWAKE MICE
Posterior striatum (or the tail of the striatum) receives inputs from various cortical structures and thalamic nuclei, including projections from the auditory cortex and Posterior thalamus, respectively. Although recent studies have begun to elucidate the role of this striatal region in auditory discrimination or active avoidance, our knowledge is very limited how the microcircuits in the Posterior striatum contribute to neural processes. To get deeper insights into the function of the Posterior striatum, we analysed the spiking activity of individual neurons in freely moving and head-fixed mice. We performed electrophysiological recordings with tetrodes or silicon probes and observed that appr. 40% of the single units increased their spiking associated with the behaviour of the animal. For instance, we found neurons whose activity was linked to exploration/movement (14/76), resting (12/76), grooming (3/76) or licking (1/76). In addition, the firing rate of some neurons was also increased upon presentation of sensory stimuli, including shock (13/75) or sound delivery (11/75). However, the majority of neurons in the Posterior striatum were tonically active and did not change their firing rate either as a result of the behaviour of the animal or in response to these external stimuli.Our data show that the activity of a large portion of Posterior striatal neurons is linked to different behaviours and to delivery of noxious or sensory stimuli. These observations suggest that neural circuits comprising the Posterior striatum may be involved in shifting behavioural actions controlled by environmental inputs.