HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 96/6/2905    most recent 00481.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Web of Science (1) Citing Articles via Google Scholar Google Scholar Articles by Zhang, H. Articles by Kelly, J. B. Search for Related Content PubMed PubMed Citation Articles by Zhang, H. Articles by Kelly, J. B.

Responses of Neurons in the Rat's Ventral Nucleus of the Lateral Lemniscus to Amplitude-Modulated Tones

Laboratory of Sensory Neuroscience, Department of Psychology, Carleton University, Ottawa, Ontario, Canada

Submitted 5 May 2006; accepted in final form 19 August 2006

Recordings were made from single neurons in the rat's ventral nucleus of the lateral lemniscus (VNLL) to determine responses to amplitude-modulated (AM) tones. The neurons were first characterized on the basis of their response to tone bursts presented to the contralateral ear and a distinction was made between those with transient onset responses and those with sustained responses. Sinusoidal AM tones were then presented to the contralateral ear with a carrier that matched the neuron's characteristic frequency (CF). Modulation transfer functions were generated on the basis of firing rate (MTF_FR) and vector strength (MTF_VS). Ninety-two percent of onset neurons that responded continuously to AM tones had band-pass MTF_FRs with best modulation frequencies from 10 to 300 Hz. Fifty-four percent of sustained neurons had band-pass MTF_FRs with best modulation frequencies from 10 to 500 Hz; other neurons had band-suppressed, all-pass, low-pass, or high-pass functions. Most neurons showed either band-pass or low-pass MTF_VS. Responses were well synchronized to the modulation cycle with maximum vector strengths ranging from 0.37 to 0.98 for sustained neurons and 0.78 to 0.99 for onset neurons. The upper frequency limit for response synchrony was higher than that reported for inferior colliculus, but lower than that seen in more peripheral structures. Results suggest that VNLL neurons, especially those with onset responses to tone bursts, are sensitive to temporal features of sounds and narrowly tuned to different modulation rates. However, there was no evidence of a topographic relation between dorsoventral position along the length of VNLL and best modulation frequency as determined by either firing rate or vector strength.