Very rapid adaptation in the guinea pig auditory nerve

Informational and neural adaptation curves are asynchronous

“…For example, Lockhead (1966) varied both stimulus duration (200 vs. 8 msec) and luminance (no filter vs. 1 log unit neutral density filter) in absolute identification of line This research was supported by a grant from the Natural Sciences and Engineering Research Council of Canada. I am grateful to Ken Norwich for many discussions regarding this work and for his insightful comments on this paper; for bringing the papers by Yates, Robertson, and Johnstone (1985) and Cleland and Enroth-Cugell (1968) to my attention; for supplying the simplex optimizationalgorithm; and for providing access to his own unpublished work. I thank Odie Geiger, Steven Lindsay, and Kelly Davidson for help with running subjects, and Shuji Mori for help with the setup for the visual stimuli.…”

“…This curve will be taken as a prototype of neural adaptation in the auditory receptor system, and will be compared in detail with psychophysical data in a later section of this paper. It should be noted that earlier adaptation curves that exhibited slower adaptation, such as those of Galambos and Davis (1943) and others since, were probably taken from more central fibers (see Galambos & Davis, 1948;Yates et al, 1985). Apparently the very rapid adaptation discovered by Yates et al (1985) is characteristic only of the primary receptor-neuron unit itself, which is, of course, the system to which Norwich's theory is supposed to apply.…”

“…A typical neural adaptation curve measured for a single auditory nerve (spiral ganglion) fiber in the guinea pig (characteristic frequency in the range 14-27 kHz) is shown in Figure 1 (Yates, Robertson, & Johnstone, 1985). Notice that the rate of firing measured in the neuron decreased rapidly as time from the onset of the auditory stimulus increased, dropping from about 287 impulses per second shortly (about 2 msec) after stimulus onset to about 67 impulses per second at about 51 msec after stimulus onset.…”

“…The ceO bad a characteristic frequency in the range 14-27 kHz; the specilic frequency for this ceO was not reported, since it was typical of aUceUs recorded. Points were read from a peristimulus histogram ( Figure 5 in Yates, Robertson, & Johnstone, 1985 can be written as Notice that we are assuming that the noise variance, N2, is constant over time, since it is added by the sampling process rather than sampled by it (similarly to the error term in the general linear model). Inserting Equation 3 into Equation 1 yields an expression for the neural activity of a receptor-neuron unit in response to a stimulus of constant intensity:…”

Direct comparison between properties of adaptation of the auditory nerve and the ventral cochlear nucleus in response to repetitive clicks

“…Adaptation properties of primary auditory neurons have been assessed by several authors having recorded either compound action potentials (Peake et al, 1962a,b;Eggermont and Spoor, 1973;Gorga and Abbas, 1981;Abbas, 1984;Schreiner, 1990, 1992) or firing patterns from single auditory-nerve fibers (Kiang et al, 1965a;Smith and Zwislocki, 1975;Smith, 1977Smith, , 1979Harris and Dallos, 1979;Westerman and Smith, 1984;Yates et al, 1985;Rhode and Smith, 1985;Chimento and Schreiner, 1991;Javel, 1996;Taberner and Liberman, 2005), in response to either long pure tones or trains of repetitive tone bursts or clicks. The adaptation time course displayed by primary auditory neurons was described to consist essentially of three stages: a rapid decrease of compound-action-potential amplitude or firing rate during the first few milliseconds of stimulation (rapid adaptation), followed by a slower decrease (short-term adaptation) and, finally, a steady state.…”