Peggy L. Edds-Walton and Richard R. Fay (2008): Directional and frequency
response characteristics in the descending octaval nucleus of the toadfish (
Opsanus tau ). J. Comp. Physiol. A 194(12), 1013-1029.
Abstract: This study is a continuation of a long-term investigation of the
auditory circuit in the oyster toadfish, Opsanus tau. Input from the
auditory periphery projects to the ipsilateral descending octaval nucleus
(DON). Ipsilateral and contralateral DONs project to the auditory midbrain,
where a previous study indicated that both frequency tuning and directional
sharpening are present. To better understand the transformation of auditory
information along the auditory pathway, we have examined over 400 units in
the DON to characterize frequency and directional information encoded in the
dorsolateral division of the nucleus. Background activity was primarily low
(<10 spikes/s) or absent. The maximum coefficient of synchronization was
equivalent to the periphery (R = 0.9) and substantially better than in the
midbrain. The majority of DON units (79%) responded best to stimulus
frequencies of 84?141 Hz and were broadly tuned. DON cells retain or enhance
the directional character of their peripheral input (s); however,
characteristic axes were distributed in all quadrants around the fish,
providing further evidence that binaural computations may first occur in the
DON of this species.
URL: http://www.springerlink.com/content/f55325rx28p34v8k/
For reprints please contact Peggy L. Edds-Walton (Email:
Kind regards
Sonja
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Dr. Sonja Amoser
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3400 Weidlingbach
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