The thalamus is a “Grand Central Station” for sensory information coming to our brains. Almost every sight, sound, taste and touch we perceive travels to our brain’s cortex via the thalamus. It is theorized that the thalamus plays a major role in consciousness itself. Not only does sensory information pass through the thalamus, it is also processed and transformed by the thalamus so our cortex can better understand and interpret these signals from the world around us.

One powerful type of transformation comes from interactions between excitatory neurons that carry data to the neocortex and inhibitory neurons of the thalamic reticular nucleus, or TRN, that regulate flow of that data. Although the TRN has long been recognized as important, much less has been known about what kinds of cells are in the TRN, how they are organized and how they function.

Now a paper published in the journal Nature addresses those questions. Researchers led by corresponding author Scott Cruikshank, Ph.D., and co-authors Rosa I. Martinez-Garcia, Ph.D., Bettina Voelcker, Ph.D., and Barry Connors, Ph.D., show that the somatosensory part of the TRN is divided into two functionally distinct sub-circuits. Each has its own types of genetically defined neurons that are topographically segregated, are physiologically distinct and connect reciprocally with independent thalamocortical nuclei via dynamically divergent synapses.