title: The effects of increased central serotonergic activity on prepulse inhibition and habituation of the human startle response.
abstract: Sensorimotor gating is critical to normal brain functioning, and disruptions are associated with certain mental illnesses, such as schizophrenia. Prepulse inhibition of the acoustic startle reflex (ASR) (PPI) is an operational measure of sensorimotor gating, of which evidence for a serotonergic modulation is currently inconsistent. In a double-blind placebo-controlled crossover design, 18 healthy male volunteers received either placebo or a dose of 10 mg of escitalopram (SSRI), after which they were tested in both PPI and habituation of the startle reflex paradigms. No significant differences between the two treatments were observed on PPI, although escitalopram was found to significantly delay habituation of the ASR. In the current study, escitalopram was found to delay habituation, but it did not affect PPI in healthy male volunteers. As escitalopram is a highly specific SSRI, the results suggest that an increased serotonergic activity disrupts habituation, but not PPI in healthy volunteers.
authors.affiliation: Center for Neuropsychiatric Schizophrenia Research, Psychiatric Center Glostrup, University of Copenhagen, Glostrup, Denmark.
authors.forename: Kristian S
authors.initials: KS
authors.lastname: Jensen
authors.forename: Bob
authors.initials: B
authors.lastname: Oranje
authors.forename: Malene
authors.initials: M
authors.lastname: Wienberg
authors.forename: Birte Y
authors.initials: BY
authors.lastname: Glenthøj
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D015283:Citalopram / Q000494:pharmacology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006185:Habituation, Psychophysiologic / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008297:Male; D009433:Neural Inhibition / Q000187:drug effects* / Q000502:physiology; D009434:Neural Pathways / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D015990:Placebo Effect; D011930:Reaction Time / Q000187:drug effects / Q000502:physiology; D013216:Reflex, Startle / Q000187:drug effects* / Q000502:physiology; D012701:Serotonin / Q000378:metabolism*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology
chemical_list: D015283:Citalopram; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors