Lateral geniculate spikes, muscle atonia and startle response elicited by auditory stimuli as a function of stimulus parameters and arousal state.

TitleLateral geniculate spikes, muscle atonia and startle response elicited by auditory stimuli as a function of stimulus parameters and arousal state.
Publication TypeJournal Article
Year of Publication1989
AuthorsWu MF, Mallick BN, Siegel JM
JournalBrain Res
Volume499
Issue1
Pagination7-17
Date Published1989 Oct 09
ISSN0006-8993
KeywordsAcoustic Stimulation, Action Potentials, Animals, Arousal, Auditory Pathways, Cats, Geniculate Bodies, Muscle Tonus, Reflex, Startle
Abstract

We have investigated the motor and ponto-geniculo-occipital (PGO) wave response to startle eliciting stimuli in the unanesthetized cat. We found that the amplitude of the PGO spike recorded in the lateral geniculate nucleus (LGN) increases monotonically with increasing intensities of auditory stimuli. In contrast, the motor response to low intensity (less than 75 dB) stimuli is characterized by electromyographic (EMG) suppression, while at higher intensities an EMG excitation is superimposed on this suppression. Thus PGO elicitation is accompanied by EMG suppression at low intensities and by a net EMG excitation at high intensities. While the amplitude of the auditory elicited PGO response is a graded function of stimulus intensity, somatic stimuli tend to elicit the PGO response in all-or-none fashion. Both the motor and PGO responses to sensory stimulation change with behavioral state. The EMG suppression by auditory stimulation increases in duration during the transition to rapid eye movement (REM) sleep. Elicited PGO amplitude is highest in transitional sleep, lower in quiet waking and REM sleep and lowest in active waking. Prepulse inhibition of PGO spikes is greatly attenuated during transitional and REM sleep. We hypothesize the existence of 3 phasic response systems, a motor suppression system, a motor excitation (startle) system and a PGO elicitation system. While these systems are triggered concurrently by intense phasic stimuli in waking, they are modulated independently by stimulus intensity and behavioral state, and have different rates of habituation. These systems act in concert to produce behavioral responses to sudden onset stimuli.

DOI10.1016/0006-8993(89)91130-x
Alternate JournalBrain Res
PubMed ID2804671
Grant ListMH43811 / MH / NIMH NIH HHS / United States
NS14610 / NS / NINDS NIH HHS / United States