title: Intracortical convergence of layer 6 neurons.
abstract: Axonal branches from a subset of neurons in cerebral cortical layer 6 innervate both cortical layer 4 and the thalamus. As such, these neurons are poised to modulate thalamocortical transmission at multiple forebrain sites. Here, we examined the functional organization of the layer 6 intracortical projections in auditory, somatosensory, and visual cortical areas using an optogenetic approach to specifically target these neurons. We characterized the anatomical and physiological organization of these projections using laser-scanning photostimulation to functionally map the elicited postsynaptic responses in layer 4. We found that these responses originated from regions over 1 mm in width, eliciting short-term facilitating responses. These results indicate that intracortical modulation of layer 4 occurs through widespread layer 6 projections in each sensory cortical area.
authors: Department of Comparative Biomedical Sciences, Louisiana State University, School of Veterinary Medicine, Baton Rouge, Louisiana 70803, USA. cclee@lsu.edu
authors: Charles C
authors: CC
authors: Lee
authors: Ying-Wan
authors: YW
authors: Lam
authors: S Murray
authors: SM
authors: Sherman
mesh_terms: D000818:Animals; D001303:Auditory Cortex / Q000502:physiology*; D001931:Brain Mapping; D051379:Mice; D008822:Mice, Transgenic; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology; D013788:Thalamus / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*