Fig. 4.

Asymmetric GAD₆₇ immunoreactivity extends for at least 4 mm rostrocaudally. Sequential transverse sections (30-μm-thick, 1:4 series) from spinal cord segments L6–L7 of a unilaterally stand-trained spinal cat immunolabeled for GAD₆₇ are shown. Five representative sections ∼500 μm apart are shown in sequential order rostrocaudally (A–E). Ipsilateral sections (Trained side) are shown at the top, and the corresponding contralateral sections (Non-trained side) are shown at the bottom. Increased GAD₆₇immunoreactivity is limited to lamina IX (dotted area) neurons on the trained side. The distribution of highly labeled cells corresponds to the location of the semimembranosus and semitendinosus motor pools (Vanderhorst and Holstege, 1997). Scale bar, 500 μm.