TY - JOUR
T1 - Experience-dependent plasticity in S1 caused by noncoincident inputs
AU - Blake, David T.
AU - Strata, Fabrizio
AU - Kempter, Richard
AU - Merzenich, Michael M.
PY - 2005/9
Y1 - 2005/9
N2 - Prior work has shown that coincident inputs became corepresented in somatic sensory cortex. In this study, the hypothesis that the corepresentation of digits required synchronous inputs was tested, and the daily development of two-digit receptive fields was observed with cortical implants. Two adult primates detected temporal differences in tap pairs delivered to two adjacent digits. With stimulus onset asynchronies of ≥100 ms, representations changed to include two-digit receptive fields across the first 4 wk of training. In addition, receptive fields at sites responsive to the taps enlarged more than twofold, and receptive fields at sites not responsive to the taps had no significant areal change. Further training did not increase the expression of two-digit receptive fields. Cortical responses to the taps were not dependent on the interval length. Stimuli preceding a hit, miss, false positives, and true negatives differed in the ongoing cortical rate from 50 to 100 ms after the stimulus but did not differ in the initial, principal, response to the taps. Response latencies to the emergent responses averaged 4.3 ms longer than old responses, which occurs if plasticity is cortical in origin. New response correlations developed in parallel with the new receptive fields. These data show corepresentation can be caused by presentation of stimuli across a longer time window than predicted by spike-timing-dependent plasticity and suggest that increased cortical excitability accompanies new task learning.
AB - Prior work has shown that coincident inputs became corepresented in somatic sensory cortex. In this study, the hypothesis that the corepresentation of digits required synchronous inputs was tested, and the daily development of two-digit receptive fields was observed with cortical implants. Two adult primates detected temporal differences in tap pairs delivered to two adjacent digits. With stimulus onset asynchronies of ≥100 ms, representations changed to include two-digit receptive fields across the first 4 wk of training. In addition, receptive fields at sites responsive to the taps enlarged more than twofold, and receptive fields at sites not responsive to the taps had no significant areal change. Further training did not increase the expression of two-digit receptive fields. Cortical responses to the taps were not dependent on the interval length. Stimuli preceding a hit, miss, false positives, and true negatives differed in the ongoing cortical rate from 50 to 100 ms after the stimulus but did not differ in the initial, principal, response to the taps. Response latencies to the emergent responses averaged 4.3 ms longer than old responses, which occurs if plasticity is cortical in origin. New response correlations developed in parallel with the new receptive fields. These data show corepresentation can be caused by presentation of stimuli across a longer time window than predicted by spike-timing-dependent plasticity and suggest that increased cortical excitability accompanies new task learning.
UR - http://www.scopus.com/inward/record.url?scp=23944458660&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=23944458660&partnerID=8YFLogxK
U2 - 10.1152/jn.00172.2005
DO - 10.1152/jn.00172.2005
M3 - Article
C2 - 16105958
AN - SCOPUS:23944458660
SN - 0022-3077
VL - 94
SP - 2239
EP - 2250
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
IS - 3
ER -