Sensorimotor Convergence in Circuitry of the Motor Cortex.

Scientists and philosophers have long appreciated that active somatosensation requires the sensory and motor systems to exchange information about body the body's movements as well as touch in order to accurately interpret incoming somatosensory information and plan future movements. However, the circuitry underlying this sensory and motor integration is complicated and is difficult to study without tools to label specific cellular components in the various brain regions involved. Here, I review the general pathways that convey ascending sensory and descending motor information, using the rodent whisker system as a model to take advantage of the cell type specificity possible in this model. I then detail the circuits in motor cortex in which incoming information from somatosensory cortex and thalamus is integrated. I close with a brief description of changes in these circuits during motor learning.