Fig. 1.

Development of hemorrhagic central post-stroke pain hypersensitivity induced by intra-thalamic collagenase microinjection. A Photomicrograph of a 600-μm slice showing the hemorrhagic lesion site in the thalamus following unilateral intra-thalamic collagenase (ITC) microinjection. Scale bar, 1 mm. B Development of central post-stroke pain hypersensitivity to mechanical stimuli applied to both hind paws induced by ITC microinjection. Intra-thalamic saline (ITS) injection served as the control. III, third ventricle; contra, contralateral; ic, internal capsule; ipsi, ipsilateral; mt, mammillothalamic tract; Po, posterior thalamic nuclear group; PWMT, paw-withdrawal mechanical threshold; VPL, ventral posterolateral nucleus of the thalamus; VPM, ventral posteromedial nucleus of the thalamus. ***P < 0.001 ITC ipsi vs ITS ipsi; ^### P < 0.001 ITC contra vs ITS contra, n = 6–8 animals/group.