Timing and Convergence of Ensemble Activity Govern Auditory Thalamocortical Transmission

Coordinated neuronal activity plays an important role in information processing and transmission in the brain. While ensembles' activity provides a more specific and less noisy version of sensory stimulus information than single neurons, their role in information transmission in the auditory pathway remains unclear. We investigated the effects of ensemble activity in the medial geniculate body (MGB) on the activation of neurons in the primary auditory cortex (A1) in female rats. MGB ensembles synchronized within narrow time windows more effectively induced A1 responses than single neurons or ensembles defined in broader time windows. This was facilitated by the convergence of ensemble inputs onto target neurons. Transmission efficacy was higher for narrow-spiking (NS) A1 neurons compared with broad-spiking (BS) neurons. Cortical UP states in isolation had no discernable effect on the transmission efficacy of thalamic cNEs. These findings highlight neuronal ensembles as focal functional units that enhance information transmission in the brain.