Fig. 6

Animals with excellent motor recovery show specific regional organization of distinct microcircuitry in the contralesional cortex for the targeting kinematics of skilled grasping. a Side view (cutout) of a rat performing single pellet grasping. The paw trajectory of a successful grasp is superimposed. The furthest extension of the paw, location x, was automatically detected to capture the grasping trajectory in relation to the position of the sugar pellet. b–d Spatial distribution of the furthest extension calculated using every grasping trial under “light-off” (I) and “light-on” (II) conditions; (III) relative distance between “light-off” and “light-on” (* = position of the sugar pellet). Therefore, the spatial distribution (I) and (II) are marginalized onto the x-location, before subtracting the resulting one-dimensional distributions to obtain (III). b Targeting of the paw to its final position over the sugar pellet in “sham-operated” animals was unaffected by light stimulation at positions 1–3 of the sensorimotor cortex independently or by concurrent light exposure of all cortical positions (“all positions”: positions 1–3 together). c Animals of the “Anti-Nogo/Training” group with excellent recovery of grasping reached too far when the recrossed corticospinal neurons were inhibited in the contralesional premotor cortex position 1 or too short when the neurons in M1 (pos. 2) were silenced, whereas silencing close to S1 (Fig. 5d, pos. 3) did not affect the grasping behavior under “light-on” conditions. d Paw targeting of the “Spontaneous recovery” animals was poor overall and only significantly altered when all three cortical positions were optogenetically silenced at the same time (all position)