Effects of chloral hydrate, @entity4485 , XXXX , and curare on the auditory middle latency response.

@entity4485 @entity4094 @entity840 @entity3652 @entity19695 @entity17166
Changes in threshold, latency, and amplitude of the auditory middle latency response (MLR) with anesthesia and @entity4094 were studied in @entity840 . Although each component of the surface-recorded MLR was altered by @entity17166 and nonbarbiturate agents, the early positive wave (wave A) was always present, and the later waves were generally identifiable at moderate levels of anesthesia. MLR threshold was not affected by anesthesia or curare. @entity4485 , chloral @entity19695 , and @entity3652 each caused an increase in the latency of all MLR components, with increases progressively marked for later waves. Amplitude changes were more complex. Wave A increased in amplitude with anesthesia, while wave C decreased or disappeared temporarily. Wave B showed mixed amplitude changes. Changes in MLR associated with anesthesia were generally more pronounced at a stimulation rate of 10/sec as compared to 4/sec. No changes in waveform morphology or latency were seen with @entity4094 . The results provide evidence in support of separate neurogenic substrates for the different components of the @entity840 temporal lobe MLR. The presence of the MLR with moderate levels of anesthesia indicates that this animal is an appropriate model for studying the MLR in experiments requiring anesthesia and immobilization.
