Department of Mathematics
 Search | Help | Login | pdf version | printable version

Math @ Duke





.......................

.......................


Publications [#244042] of Michael C. Reed

Papers Published

  1. Blum, JJ; Reed, MC, Further studies of a model for azimuthal encoding: Lateral superior olive neuron response curves and developmental processes, The Journal of the Acoustical Society of America, vol. 90 no. 4 I (1991), pp. 1968-1978, ISSN 0001-4966 [doi]
    (last updated on 2017/12/11)

    Abstract:
    A number of investigators have published measurements of the outputs of single neurons from the lateral superior olive (LSO) of the cat for a variety of auditory signals. The response curves show a very wide range of shapes and thresholds. In this paper, the single neuron response curves predicted by a previously published model for the encoding of azimuthal location by the LSO to the experimental curves are compared. The predicted curves are in good qualitative agreement with the experiments and, in addition, the model provides an explanation of the seemingly paradoxical drop in output as interaural intensity difference (IID) is held fixed and absolute intensities are raised. The particular shape of the response curve depends on the location of the LSO neuron examined. In the model, two possible developmental programs to form the adult pattern of connections from the anteroventral cochlear nucleus and the medial nucleus of the trapezoid body onto the LSO are also examined. In the first, connections are made by a forward stochastic process in which there is a limit on the numbers of synapses formed on each LSO cell. In the second, there is no such limit, but in later developmental stages pruning of synapses occurs which reduces their number to the limit. Both schemes give similar adult connectional patterns. The LSO response curves generated by the model are similar to those observed in LSO neurons of the developing gerbil by Sanes and Rubel [J. Neurosci. 8, 682-700 (1988)]. Thus the model mechanism not only encodes azimuthal location by activity across the population of neurons, but is also consistent with single unit neurophysiological measurements of LSO output in both developing and adult animals.

 

dept@math.duke.edu
ph: 919.660.2800
fax: 919.660.2821

Mathematics Department
Duke University, Box 90320
Durham, NC 27708-0320