Processing in layer 4 of the neocortical circuit: new insights from visual and somatosensory cortex.
Recent experimental and theoretical results in cat primary visual cortex and in the whisker-barrel fields of rodent primary somatosensory cortex suggest common organizing principles for layer 4, the primary recipient of sensory input from the thalamus. Response tuning of layer 4 cells is largely determined by a local interplay of feed-forward excitation (directly from the thalamus) and inhibition (from layer 4 inhibitory interneurons driven by the thalamus). Feed-forward inhibition dominates excitation, inherits its tuning from the thalamic input, and sharpens the tuning of excitatory cells. Recurrent excitation enhances responses to effective stimuli.
Miller
K D
KD
Departments of Physiology and Otolaryngology, WM Keck Center for Integrative Neuroscience, Sloan-Swartz Center for Theoretical Neurobiology at UCSF, University of California, San Francisco, CA 94143-0444, USA. ken@phy.ucsf.edu
Pinto
D J
DJ
Simons
D J
DJ
D000200:Action Potentials / Q000502:physiology; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D008959:Models, Neurological; D019579:Neocortex / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D013003:Somatosensory Cortex / Q000502:physiology; D013788:Thalamus / Q000502:physiology; D014738:Vibrissae / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology