Buspirone decreases physiological reactivity to unconditioned and conditioned aversive stimuli.
BACKGROUND
Serotonergic pathways are thought to be important in mediating the effects of aversive events.


OBJECTIVE
To investigate the effects of buspirone, a 5-HT(1A) partial agonist, on habituation and extinction in an aversive classical conditioning model.


METHODS
Forty healthy male volunteers were randomly assigned to a single dose of buspirone (10 mg) or placebo. They filled in questionnaires of anxiety and depression at baseline and visual analogue scales of tension and anxiety before and at 60, 120 and 150 min after drug administration. Their skin conductance responses to auditory stimuli were measured on the conditioning model 2 h after drug intake.


RESULTS
There were no differences between groups on depression or anxiety. Buspirone decreased the amplitude of the skin conductance response and the number of spontaneous fluctuations in both the habituation and extinction phases but had no effect on skin conductance level. Buspirone also attenuated the unconditioned response to the white noise and the response to the first tone. Visual analogue ratings of tension and anxiety decreased after buspirone.


CONCLUSIONS
Buspirone decreased physiological reactivity in an aversive classical conditioning model. It had anxiolytic effects on both conditioned and unconditioned anxiety. This might be due to its multiple actions on 5-HT receptors.
Bond
Alyson J
AJ
Division of Psychological Medicine, Institute of Psychiatry, Kings College, London SE5 8AF, UK. a.bond@iop.kcl.ac.uk
Wingrove
Janet
J
Baylis
Maxine
M
Dalton
Jeff
J
D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D001007:Anxiety / Q000523:psychology; D002065:Buspirone / Q000494:pharmacology*; D003214:Conditioning, Classical / Q000187:drug effects*; D003863:Depression / Q000523:psychology; D004311:Double-Blind Method; D005712:Galvanic Skin Response / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011985:Receptors, Serotonin / Q000187:drug effects*; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists; D002065:Buspirone