| dc.description.abstract | We studied primary-somatosensory cortical plasticity due to selective stimulation of the sensory periphery by
two procedures of active exploration in adult rats. Subjects, left with only three adjacent whiskers, were
trained in a roughness discrimination task or maintained in a tactile enriched environment. Either training or
enrichment produced 3-fold increases in the barrel cortex areas of behaviorally-engaged whisker
representations, in their zones of overlap. While the overall areas of representation expanded dramatically, the
domains of exclusive principal whisker responses were virtually identical in enriched vs normal rats and were
significantly smaller than either group in roughness discrimination-trained rats. When animals were trained or
exposed to enriched environments with the three whiskers arrayed in an arc or row, very equivalent overlaps
in representations were recorded across their greatly-enlarged whisker representation zones. This equivalence
in distortion in these behavioral preparations is in contradistinction to the normal rat, where overlap is
strongly biased only along rows, probably reflecting the establishment of different relations with the
neighboring cortical columns. Overall, plasticity phenomena are argued to be consistent with the predictions
of competitive Hebbian network plasticity. | |
