This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Bitsios, P. Articles by Szabadi, E. Search for Related Content PubMed PubMed Citation Articles by Bitsios, P. Articles by Szabadi, E. Social Bookmarking                         What's this?

Comparison of the effects of diazepam on the fear-potentiated startle reflex and the fear-inhibited light reflex in man

A. Philpott

R. W. Langley

Division of Psychiatry, University of Nottingham, Nottingham, UK

C. M. Bradshaw

Psychopharmacology Section Division of Psychiatry University of Nottingham Floor B, Medical School Queen's Medical Centre Nottingham NG7 2UH, UK C.M.Bradshaw{at}nottingham.ac.uk

E. Szabadi

Division of Psychiatry, University of Nottingham, Nottingham, UK

It has been shown previously that the amplitude of the acoustic startle reflex is enhanced, and the amplitude of the light reflex reduced, when subjects anticipate an aversive event, compared to periods when subjects are resting (`fear-potentiated startle reflex' and `fear-inhibited light reflex'). We examined whether the anxiolytic diazepam would reverse the effects of threat on the startle and pupillary reflexes. Twelve male volunteers participated in three weekly sessions in which they received oral treatment with placebo, diazepam 5 mg and diazepam 10 mg, according to a balanced crossover double-blind design. One hour after ingestion of the treatments, miotic responses to light pulses and electromyographic responses of the orbicularis oculi muscle to sound pulses were elicited during alternating periods in which the threat of an electric shock (electrodes attached to the subject's wrist) was present (THREAT) and absent (SAFE). The THREAT condition was associated with a signicant increase in the amplitude of the electromyographic (EMG) response, a signicant reduction of the miotic response amplitude, and an increase in self-rated anxiety. Diazepam attenuated all these effects of THREAT. Diazepam did not affect the amplitude of the miotic response under the SAFE condition, but did suppress the EMG response under this condition.These results confirm the validity of the fear-potentiated startle reflex and fear-inhibited light reflex as laboratory models of human anxiety, and reveal some differences between the effects of diazepam on the two reflexes.

Key Words: anxiety • diazepam • fear • light reflex • startle reflex

Journal of Psychopharmacology, Vol. 13, No. 3, 226-234 (1999)
DOI: 10.1177/026988119901300303


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				K.E. Demos, W.M. Kelley, S.L. Ryan, F.C. Davis, and P.J. Whalen Human Amygdala Sensitivity to the Pupil Size of Others Cereb Cortex, December 1, 2008; 18(12): 2729 - 2734. [Abstract] [Full Text] [PDF]

				K. Al-Abduljawad, F. Baqui, R. Langley, C. Bradshaw, and E. Szabadi Effects of threat of electric shock and diazepam on the N1/P2 auditory-evoked potential elicited by low-intensity auditory stimuli J Psychopharmacol, November 1, 2008; 22(8): 828 - 835. [Abstract] [PDF]

				S. J. Graham, J. C. Scaife, R. W. Langley, C. M. Bradshaw, E. Szabadi, L. Xi, T. Crumley, N. Calder, K. Gottesdiener, and J. A. Wagner Effects of lorazepam on fear-potentiated startle responses in man J Psychopharmacol, May 1, 2005; 19(3): 249 - 258. [Abstract] [PDF]

				S. G. Giakoumaki, E. Hourdaki, V. Grinakis, K. Theou, and P. Bitsios Effects of peripheral sympathetic blockade with dapiprazole on the fear-inhibited light reflex J Psychopharmacol, March 1, 2005; 19(2): 139 - 148. [Abstract] [PDF]

				S. J. Graham, J. C. Scaife, A. M. B. Verduzco, R. W. Langley, C. M. Bradshaw, and E. Szabadi Effects of Quetiapine and Haloperidol on Prepulse Inhibition of the Acoustic Startle (Eyeblink) Response and the N1/P2 Auditory Evoked Response in Man J Psychopharmacol, June 1, 2004; 18(2): 173 - 180. [Abstract] [PDF]

				S. J. Graham, R. W. Langley, A. M. B. Verduzco, C. M. Bradshaw, and E. Szabadi Effects of ketanserin and haloperidol on prepulse inhibition of the acoustic startle (eyeblink) response and the N1/P2 auditory evoked response in man J Psychopharmacol, January 1, 2002; 16(1): 15 - 22. [Abstract] [PDF]

				K. A. J. Abduljawad, R. W. Langley, C. M. Bradshaw, and E. Szabadi Effects of clonidine and diazepam on prepulse inhibition of the acoustic startle response and the N1/P2 auditory evoked potential in man J Psychopharmacol, July 1, 2001; 15(4): 237 - 242. [Abstract] [PDF]

				S. J. Graham, R. W. Langley, C. M. Bradshaw, and E. Szabadi Effects of haloperidol and clozapine on prepulse inhibition of the acoustic startle response and the N1/P2 auditory evoked potential in man J Psychopharmacol, July 1, 2001; 15(4): 243 - 250. [Abstract] [PDF]

				S. J. Tavernor, K. A. J. Abduljawad, R. W. Langley, C. M. Bradshaw, and E. Szabadi Effects of pentagastrin and the cold pressor test on the acoustic startle response and pupillary function in man J Psychopharmacol, July 1, 2000; 14(4): 387 - 394. [Abstract] [PDF]