Spatial Sound Detection and the Role of the Inferior Colliculus in the Long-Evans Rat

• Published in: Acta oto-laryngologica 1999, Vol.119 (3), p.326-332
• Main Authors: ZRULL, M. C, COLEMAN, J. R
• Format: Article
• Language: English
• Subjects: Animals; Behavior, Animal - physiology; Biological and medical sciences; Differential Threshold; Disorders of higher nervous function. Focal brain diseases. Central vestibular syndrome and deafness. Brain stem syndromes; Echolocation - physiology; Inferior Colliculi - physiology; Inferior Colliculi - surgery; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Nervous system (semeiology, syndromes); Neurology; Noise; Otorhinolaryngology functional investigation (larynx, voice, audiometry, vestibular function, equilibration...); Postoperative Period; Rats; Space Perception - physiology
• ISSN: 0001-6489; 1651-2251
• DOI: 10.1080/00016489950181332

The ability of Long-Evans hooded rats (n=10) to detect sounds presented from sources in the horizontal plane at 0° elevation and the effects of bilateral lesions of the inferior colliculus on these abilities were examined. Rats were trained on a directional detection task which required animals to suppress licking responses in a conditioned avoidance paradigm when 100-ms noise bursts were presented at random from speakers at 45° intervals beginning at azimuth (0°). A task performance rate was determined by reducing the correct lick suppression rate for signal trials by the proportion of incorrect suppression responses on non-signal trials. Higher performance rates were observed for stimuli presented from 0-90° than for stimuli presented in the caudal hemifield prior to surgical procedures. Bilateral lesions restricted to the inferior colliculus reduced detection performance (p