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Effects of modulation range and presentation rate of FM stimulus on auditory response properties of mouse inferior collicular neurons

LI An-An, ZHANG Ai-Ya, CHEN Qi-Cai, WU Fei-Jian

College of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China； Department of Life Sciences and Chemistry, Hubei University of Education, Wuhan 430205, China

Abstract

In natural acoustical environments, most biologically related sounds containing frequency-modulated (FM) componentsrepeat over periods of time. They are often in rapid sequence rather than in temporal isolation. Few studies examined the neuronalresponse patterns evoked by FM stimuli at different presentation rates (PR). In the present investigation, by using normalelectrophysiological technique, we specifically studied the temporal features of response of the inferior collicular (IC) neurons to FMsweeps with different modulation ranges (MR) in conditions of distinct PR in mouse. The results showed that most of the recordedneurons responded best to narrower MRs (narrow-pass, up-sweep: 60.00%, 54/90; down-sweep: 63.33%, 57/90), while a smallfraction of neurons displayed other patterns such as band-pass (up-sweep, 16.67%, 15/90; down-sweep, 18.89%, 17/90), all-pass (upsweep,18.89%, 17/90; down-sweep, 13.33%, 12/90) and wide-pass (up-sweep, 4.44%, 4/90; down-sweep, 4.44%, 4/90). Both thedischarge rate and duration of recorded neurons decreased but the latency lengthened with increase in PR, when different PRs from0.5/s to 10/s of FM sound were used. The percentage of total directional selective neurons, up-directional selective neurons, and downdirectionalselective neurons changed with the variation of PR or MR. These results indicate that temporal features of mouse midbrainneurons responding to FM sweeps are co-shaped by the MR and PR. Possible mechanisms underlying may be related to spectral andtemporal integration of the FM sound by the IC neurons.

Key words: frequency-modulated sweep; modulation range; directional selectivity; presentation rate; inferior colliculus; mouse

Received: 2010-03-09　　Accepted: 2010-04-14

Corresponding author: 陈其才,吴飞健　　E-mail: qcchen2003@yahoo.com.cn,

Citing This Article：

LI An-An, ZHANG Ai-Ya, CHEN Qi-Cai, WU Fei-Jian. Effects of modulation range and presentation rate of FM stimulus on auditory response properties of mouse inferior collicular neurons. Acta Physiol Sin 2010; 62 (3): 210-218 (in Chinese with English abstract).