A Distinct Population of L6 Neurons in Mouse V1 Mediate Cross-Callosal Communication

Through the corpus callosum, interhemispheric communication is mediated by callosal projection (CP) neurons. Using retrograde labeling, we identified a population of layer 6 (L6) excitatory neurons as the main conveyer of transcallosal information in the monocular zone of the mouse primary visual cortex (V1). Distinct from L6 corticothalamic (CT) population, V1 L6 CP neurons contribute to an extensive reciprocal network across multiple sensory cortices over two hemispheres. Receiving both local and long-range cortical inputs, they encode orientation, direction, and receptive field information, while are also highly spontaneous active. The spontaneous activity of L6 CP neurons exhibits complex relationships with brain states and stimulus presentation, distinct from the spontaneous activity patterns of the CT population. The anatomical and functional properties of these L6 CP neurons enable them to broadcast visual and nonvisual information across two hemispheres, and thus may play a role in regulating and coordinating brain-wide activity events.

Automated summary

Researchers have identified a population of layer 6 excitatory neurons in the primary visual cortex of mice that serve as the main conveyer of transcallosal information. These neurons contribute to a reciprocal network across multiple sensory cortices in two hemispheres, encoding orientation, direction, and receptive field information. The spontaneous activity of these neurons exhibits complex relationships with brain states and stimulus presentation, distinguishing them from other neuron populations.