Figure 1.

A, Sagittal section through the brainstem about 1.5 mm lateral to the midline from acute cat 1. The star shows the location of a 250 nl (3.6 mm) CNQX injection. The arrowhead indicates a recording location 1 mm caudal to the injection in rDAO (at the site of an electrolytic lesion) and the circle shows a recording site 1 mm ventral in rMAO. B, Sagittal section through the brainstem of one of the behavioral inactivation cases (cat 4) 1.2 mm lateral to the midline. The arrows show the locations of four electrode penetrations through the brainstem and IO. Gliosis is visible along the penetrations above and within the IO; however, CNQX injections did not appear to produce additional loss of IO neurons.