Sound Localization After Kainic Acid Lesions of the Dorsal Nucleus of the Lateral Lemniscus in the Albino Rat

The ability of rats to localize sounds in space was determined before and after kainic acid lesions of the dorsal nucleus of the lateral lemniscus (DNLL). The rats were trained to approach a 45-ms noise burst delivered from loudspeakers on the right or left of midline. Lesions were made by local injection of kainic acid into the DNLL. Rats with unilateral lesions of DNLL were impaired in their postoperative ability to localize a single noise burst. Rats with bilateral lesions also had deficits in postoperative performance, but the severity of the impairment was not substantially greater than that expected from a unilateral lesion. The mean pre- and postoperative minimum audible angles were 14.8 degrees and 40.4 degrees for rats with complete unilateral lesions and 13.5 degrees and 36.0 degrees for rats with bilateral lesions.