title: Endogenous cortisol suppression with metyrapone enhances acoustic startle in healthy subjects.
abstract: Previous human studies have shown that excess cortisol sufficient to fully occupy central nervous system (CNS) corticosteroid receptors may reduce startle eye blink. The present study tested whether cortisol depletion and the resulting reduction in activity of CNS corticosteroid receptors has the opposite effect. In a single-blind, placebo-controlled, randomized study, eye blink EMG responses to 105 dB acoustic startle stimuli were assessed in 25 healthy subjects who received oral metyrapone (1500 mg) to suppress endogenous cortisol production, while 24 controls received oral placebo. As expected, metyrapone significantly reduced salivary cortisol, indicating effective endogenous cortisol suppression. Startle eye blink responses were significantly increased in the metyrapone group. Short-term habituation of the startle reflex was not different between groups. Our results suggest that startle is enhanced during depletion of cortisol. This effect may be mediated by CNS mechanisms controlling cortisol feedback.
authors.affiliation: Institute of Psychobiology, University of Trier, Trier, Germany. roem1303@uni-trier.de
authors.forename: Sonja
authors.initials: S
authors.lastname: Roemer
authors.forename: Frauke
authors.initials: F
authors.lastname: Nees
authors.forename: Steffen
authors.initials: S
authors.lastname: Richter
authors.forename: Terry D
authors.initials: TD
authors.lastname: Blumenthal
authors.forename: Hartmut
authors.initials: H
authors.lastname: Schächinger
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000704:Analysis of Variance; D000963:Antimetabolites / Q000008:administration & dosage / Q000494:pharmacology; D001007:Anxiety; D001307:Auditory Perception / Q000187:drug effects / Q000502:physiology*; D001767:Blinking; D002940:Circadian Rhythm; D004576:Electromyography; D005260:Female; D006185:Habituation, Psychophysiologic; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis* / Q000037:antagonists & inhibitors; D008297:Male; D008797:Metyrapone / Q000494:pharmacology*; D013216:Reflex, Startle / Q000187:drug effects / Q000502:physiology*; D012463:Saliva / Q000737:chemistry; D016037:Single-Blind Method; D055815:Young Adult
chemical_list: D000963:Antimetabolites; D006854:Hydrocortisone; D008797:Metyrapone