Effects of isoflurane on auditory middle latency (MLRs) and steady-state (SSRs) responses recorded from the temporal cortex of the rat.

Auditory steady-state responses (SSRs) are believed to result from superimposition of middle latency responses (MLRs) evoked by individual stimuli during repetitive stimulation. Our previous studies showed that besides linear addition of MLRs, other phenomena, mainly related to the adaptive properties of neural sources, interact in a complex way to generate the SSRs recorded from the temporal cortex of awake rats. The aim of this study was to evaluate the effects of the inhalational general anesthetic, isoflurane, on MLRs and SSRs at several repetition rates (30-60 Hz) recorded from the temporal cortex of rats.

Effects of isoflurane on the auditory brainstem responses and middle latency responses of rats.

Objective: To evaluate the effects of a volatile anesthetic, isoflurane, on auditory brainstem responses (ABRs) and middle latency responses (MLRs) recorded in rats.

Material And Methods: ABRs and MLRs evoked by click stimuli were simultaneously recorded in eight rats in the awake condition and during anesthesia with isoflurane at clinically relevant concentrations.

Results: Vertex-recorded ABRs showed a significant increase in the latency of waves I-IV during anesthesia and the latency changes appeared to be significantly related to the isoflurane concentration.

WINSTODEC: a stochastic deconvolution interactive program for physiological and pharmacokinetic systems.

Deconvolution allows the reconstruction of non-accessible inputs (e.g. hormone secretion rate) from their causally-related measurable effects (e.