Effects of auditory cortical lesions on pure-tone sound localization by the albino rat.

Abstract

Two-choice and three-choice tests were used to evaluate the effects of bilateral auditory cortical lesions on pure-tone sound localization by the albino rat. Both tests required that animals approach a distant sound source to obtain water reinforcement. Stimuli were single noise and tone bursts, 65 ms in duration including 20-ms rise and fall times. Tone frequencies were 2, 4, 8, 16, and 32 kHz adjusted to 40 dB (SPL) above the rat's absolute threshold. Five animals were tested in the two-choice situation following bilateral ablation of auditory cortex. Some reduction in performance was observed relative to normals, but impairments were not severe. Similar results were obtained for 2 brain-damaged animals tested in the three-choice situation. Thus, the ability to localize sounds in space remained intact after complete destruction of auditory cortex, and there was no indication of a frequency-dependent deficit.

The Neural Representation of Interaural Time Differences in Gerbils Is Transformed from Midbrain to Cortex

“…While A1 seems to play a role in localization in most mammals that have been tested (King and Middlebrooks, 2011), it does not appear necessary for sound localization in rats (Kelly and Kavanagh, 1986). It may also be that if localization was tested under more difficult (e.g., reverberant) conditions, a better match between A1 activity and behavioral performance would become apparent.…”

The acoustical cues to sound location in the rat: Measurements of directional transfer functions

“…Yet in other species, there has been considerable study of the cues, including human ͑Wightman and Kistler, 1989;Middlebrooks et al, 1989;Green, 1990͒, cat ͑Wiener et al, 1966;Moore and Irvine, 1979;Roth et al, 1980;Phillips et al, 1982;Irvine, 1987;Musicant et al, 1990;Rice et al, 1992;Xu and Middlebrooks, 2000͒, monkey ͑Spezio et al, 2000͒, ferrets ͑Carlile, 1990Schnupp et al, 2003͒, tammar wallaby ͑Coles and Guppy, 1986͒, various species of bat ͑Jen and Chen, 1988;Obrist et al, 1993;Fuzessery, 1996;Firzlaff and Schuller, 2003;Aytekin et al, 2004͒, guinea pig ͑Carlile andPettigrew, 1987;Sterbing et al, 2003͒, gerbil ͑Maki and Furukawa, 2005͒, mouse ͑Chen et al, 1995͒, and barn owl ͑Moiseff, 1989Keller et al, 1998͒. In this paper, we extend these studies to include the albino rat ͑Rattus norvegicus͒. Rats have been a common model system for the behavior ͑Beecher and Harrison, 1971;Burlile et al, 1985;Heffner and Heffner, 1985;Harrison, 1988;Heffner et al, 1994͒, anatomy ͑Beyerl, 1978Kelly, 1980;Kelly and Kavanagh, 1986;Glazier, 1978͒, physiology ͑Flammino andClopton, 1975;Inbody and Feng, 1981;Kelly and Sally, 1988;Finlayson and Caspary, 1991;Kelly and Phillips, 1991;Li and Kelly, 1992;Irvine et al, 1995;Kelly et al, 1998;…”

Auditory System

“…Using tests with two sound sources positioned symmetrically right and left of the midline, rats with complete bilateral destruction of the auditory cortex, maintain their ability to localize sound accurately (Kelly, 1980;Kelly and Glazier, 1978;Kelly and Kavanagh, 1986;Jenkins and Masterton, 1982). In contrast, ablation of the auditory cortex in other species results in severe sound localization deficits (e.g., Neff, 1968;Neff et al, 1975;Heffner and Masterton, 1990;Kavanagh and Kelly, 1987).…”