XXXX affects responses of bat inferior collicular neurons to temporally patterned sound pulses.

@entity1 @entity4943 @entity1027
Using the big brown bat, Eptesicus fuscus, as a model @entity1 auditory system, we studied the effect of @entity4943 by @entity1027 on the responses of inferior collicular (IC) neurons to temporally patterned trains of sound pulses delivered at different pulse repetition rates (PRRs) under free-field stimulation conditions. All 66 neurons isolated from eight bats either discharged one to two impulses (phasic on responders, n = 41, 62%), three to eight impulses (phasic bursters, n = 19, 29%), or many impulses throughout the entire duration of the stimulus (tonic responders, n = 6, 9%). Whereas 50 neurons responded vigorously to frequency-modulated (FM) pulses, 16 responded poorly or not at all to FM pulses. @entity1027 application increased the number of impulses of all 66 neurons in response to 4 ms pulses by 15-1,425%. The application also changed most phasic on responders into phasic bursters or tonic responders, resulting in 12 (18%) phasic on responders, 34 (52%) phasic bursters, and 20 (30%) tonic responders. Response latencies of these neurons were either shortened (n = 25, 38%) by 0.5-6.0 ms, lengthened (n = 9, 14%) by 0. 5-2.5 ms or not changed (n = 32, 48%) on @entity1027 application. Each neuron had a highest response repetition rate beyond which the neuron failed to respond. @entity1027 application increased the highest response repetition rates of 62 (94%) neurons studied. The application also increased the highest 100% pulse-locking repetition rates of 21 (32%) neurons and facilitated 27 (41%) neurons in response to more pulses at the same PRR than predrug conditions. According to average rate-based modulation transfer functions (average rate MTFs), all 66 neurons had low-pass filtering characteristics both before and after @entity1027 application. According to total discharge rate-based modulation transfer functions (total rate MTFs), filtering characteristics of these neurons can be described as band-pass (n = 52, 79%), low-pass (n = 12, 18%), or high-pass (n = 2, 3%) before @entity1027 application. @entity1027 application changed the filtering characteristics of 14 (21%) neurons. According to synchronization coefficient-based modulation transfer functions, filtering characteristics of these neurons can be described as low-pass (n = 41, 62%), all-pass (n = 11, 17%), band-suppression (n = 7, 10.5%), and band-suppression-band-pass filters (n = 7, 10.5%). @entity1027 application changed filtering characteristics of 19 (29%) neurons.
