Neural measurement of sound duration: control by excitatory-inhibitory interactions in the inferior colliculus. Export

@article{casseday:2000, abstract = {In the inferior colliculus (IC) of the big brown bat, a subpopulation of cells ( approximately 35\%) are tuned to a narrow range of sound durations. Band-pass tuning for sound duration has not been seen at lower levels of the auditory pathway. Previous work suggests that it arises at the IC through the interaction of sound-evoked, temporally offset, excitatory and inhibitory inputs. To test this hypothesis, we recorded from duration-tuned neurons in the IC and examined duration tuning before and after iontophoretic infusion of antagonists to gamma-aminobutyric acid-A (GABA(A)) (bicuculline) or glycine (strychnine). The criterion for duration tuning was that the neuron's spike count as a function of duration had a peak value at one duration or a range of durations that was >/=2 times the lowest nonzero value at longer durations. Out of 21 units tested with bicuculline, duration tuning was eliminated in 15, broadened in two, and unaltered in four. Out of 10 units tested with strychnine, duration tuning was eliminated in four, broadened in one, and unaltered in five. For units tested with both bicuculline and strychnine, bicuculline had a greater effect on reducing or abolishing duration tuning than did strychnine. Bicuculline and strychnine both produced changes in discharge pattern. There was nearly always a shift from an offset response to an onset response, indicating that in the predrug condition, inhibition arrived simultaneously with excitation or preceded it. There was often an increase in the length of the spike train, indicating that in the predrug condition, inhibition also coincided with later parts of excitation. These findings support two hypotheses. First, duration tuning is created in the IC. Second, although the construction of duration tuning varies in some details among IC neurons, it follows three rules: 1) an excitatory and an inhibitory event are temporally linked to the onset of sound but temporally offset from one another; 2) the duration of some inhibitory event must be linked to the duration of the sound; 3) an excitatory event must be linked to the offset of sound.}, author = {Casseday, J. H.}, citeulike-article-id = {1627804}, journal = {J Neurophysiol}, keywords = {acoustic, action, agentsadministration, and, animals, antagonistsadministration, auditory, bibtex-import, bicucullineadministration, chiroptera, colliculuscytology, dosage, effects, electrodes, female, gaba, glycine, implanted, inferior, inhibitiondrug, iontophoresis, linear, male, models, neural, neuronsdrug, pathwaysphysiology, perceptionphysiology, potentialsdrug, reaction, stimulation, strychnineadministration, timedrug}, month = {Sep}, number = {3}, pages = {1475--87}, posted-at = {2007-09-06 15:22:48}, priority = {2}, title = {Neural measurement of sound duration: control by excitatory-inhibitory interactions in the inferior colliculus.}, volume = {84}, year = {2000} }

TY - JOUR ID - casseday:2000 L3 - citeulike-article-id:1627804 N2 - In the inferior colliculus (IC) of the big brown bat, a subpopulation of cells ( approximately 35%) are tuned to a narrow range of sound durations. Band-pass tuning for sound duration has not been seen at lower levels of the auditory pathway. Previous work suggests that it arises at the IC through the interaction of sound-evoked, temporally offset, excitatory and inhibitory inputs. To test this hypothesis, we recorded from duration-tuned neurons in the IC and examined duration tuning before and after iontophoretic infusion of antagonists to gamma-aminobutyric acid-A (GABA(A)) (bicuculline) or glycine (strychnine). The criterion for duration tuning was that the neuron's spike count as a function of duration had a peak value at one duration or a range of durations that was >/=2 times the lowest nonzero value at longer durations. Out of 21 units tested with bicuculline, duration tuning was eliminated in 15, broadened in two, and unaltered in four. Out of 10 units tested with strychnine, duration tuning was eliminated in four, broadened in one, and unaltered in five. For units tested with both bicuculline and strychnine, bicuculline had a greater effect on reducing or abolishing duration tuning than did strychnine. Bicuculline and strychnine both produced changes in discharge pattern. There was nearly always a shift from an offset response to an onset response, indicating that in the predrug condition, inhibition arrived simultaneously with excitation or preceded it. There was often an increase in the length of the spike train, indicating that in the predrug condition, inhibition also coincided with later parts of excitation. These findings support two hypotheses. First, duration tuning is created in the IC. Second, although the construction of duration tuning varies in some details among IC neurons, it follows three rules: 1) an excitatory and an inhibitory event are temporally linked to the onset of sound but temporally offset from one another; 2) the duration of some inhibitory event must be linked to the duration of the sound; 3) an excitatory event must be linked to the offset of sound. IS - 3 JF - J Neurophysiol EP - 87 TI - Neural measurement of sound duration: control by excitatory-inhibitory interactions in the inferior colliculus. VL - 84 SP - 1475 KW - acoustic KW - action KW - agentsadministration KW - and KW - animals KW - antagonistsadministration KW - auditory KW - bibtex-import KW - bicucullineadministration KW - chiroptera KW - colliculuscytology KW - dosage KW - effects KW - electrodes KW - female KW - gaba KW - glycine KW - implanted KW - inferior KW - inhibitiondrug KW - iontophoresis KW - linear KW - male KW - models KW - neural KW - neuronsdrug KW - pathwaysphysiology KW - perceptionphysiology KW - potentialsdrug KW - reaction KW - stimulation KW - strychnineadministration KW - timedrug AU - Casseday, JH PY - 2000/Sep// ER -