The effects of electrical stimulation of the tip of rat's forepaw's digit 3 (equivalent to the Shixuan acupoint) on skin representations in primary sensorimotor cortex were studied. The conical representations of digit 2

3

4 tips were measured before and after stimulation. The results showed that stimulation of digit 3 caused no significant change in representations of tips of digit 2 and 4

but the representation of tip of digit 3 expanded significantly (P < 0. 02). This suggests that electrical stimulation of body Skin has effect of the organization of primary sensorimotor cortex (SmI) and expands the rep- resentation of the stimulated skin area. The mechanism of conical pasticity was discussed. One of the suggested reasons for representation expansion is that the subthreshold responses of neurons in the expanded area may be altered and/or elevated to supra-threshold firing level.