10/31/25 Reed Hightower: Neighboring and Contralateral Somatosensory Fields of the Hands Affect Responses of Area 3b Neuron
Neuroscience brown bag
Reed Hightower
Date: Friday, October 31, 2025
Time: 1:25- 2:15
Location: 316 Wilson Hall
Neighboring and Contralateral Somatosensory Fields of the Hands Affect Responses of Area 3b Neuron
In primary somatosensory cortex area 3b, there are few, if any, callosal connections to connect the representations of the two hands. The excitatory receptive fields of area 3b neurons have been characterized as responsive to light touches exclusively on the contralateral hand. However, our lab and others have reported that stimulating both hands at the same time or with time delays can change neuron responses relative to that on the contralateral hand alone. We have interrogated the effects of tactile stimulation at two points on the non-human primate hand across varying distances and time delays. We have observed altered cortical neuron activity as the result of stimulation of multiple somatosensory receptive fields, with simultaneous and adjacent digit stimulation appearing to produce an alternate pattern in activity to long-delayed and long-distance stimulation. A portion of the monkeys we studied had a specific unilateral lesion to disrupt the primary tactile pathway from the hand in the spinal cord. We compared the response properties of neurons from normal monkeys and monkeys at least 3 months after the spinal cord lesion. The differences in activity patterns suggest that neurons in perhaps unexpected parts of the somatosensory system may affect the responses of neurons in the hand representation of area 3b.