Abstract
The present study investigated in healthy human volunteers whether clonidine reduced the amplitude of the acoustic startle reflex and whether this effect, if found, was due to an accelerated rate of habituation. Subjects were presented with startleeliciting noise-bursts after intravenous (iv) infusion of clonidine (1.5 µg/kg) and saline on separate days. Clonidine significantly reduced the amplitude of the acoustic startle reflex (as indexed by the eyeblink component) relative to the saline treated condition. This effect was neither due to an accelerated rate of habituation of the startle reflex nor to the sedative effect of clonidine. These findings complement an earlier report (Morgan et al. 1993) that yohimbine augments the amplitude of the startle reflex in man. Taken together, the two reports indicate a new model for the clinical investigation of central alpha2 adrenoceptor function in humans.
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References
Anthony BJ (1985) In the blink of an eye: implications of reflex modification for information processing. In: Ackles PK, Jennings JR, Coles MGH (eds) Advances in psychophysiology (vol. 1). Jai, Greenwich, Conn., pp 167–218
Bond AJ, Lader MH (1974) The use of analogue scales in rating subjective feelings. Br J Med Psychol 47:211–218
Boulis NM, Kehne JH, Miserendino MJD, Davis M (1990) Differential blockade of early and late components of acoustic startle following intrathecal infusion of 6-cyano-7-nitro-quinoxaline-2, 3-dione (CNQX) onD, L-2-amino-5-phosphovaleric acid (AP-5). Brain Res 520:240–246
Cook EW III, Davis TL, Hawk LW, Spence EL, Gautier CH (1992) Fearfulness and startle potentiation during aversive visual stimuli. Psychophysiology 29:633–645
Corr PJ, Wilson GD, Fotiadou M, Kumari V, Gray NS, Checkley SA, Gray JA (1995) Personality and affective modulation of the startle reflex. Person Individ Diff 19:543–553
Davis M (1970) Effects of interstimulus interval length and variability on startle response in the rat. J Comp Physiol Psychol 72:177–192
Davis M (1984) The mammalian startle response. In: Eaton R (ed) Neural mechanisms of startle behaviour. Plenum, New York, pp 187–351
Davis M, Astrachan DL (1981) Spinal modulation of acoustic startle: opposite effects of clonidine andd-amphetamine. Psychopharmacology 75:219–225
Davis M, Cederbaum JM, Aghajanian GK, Gendelman DS (1977) Effects of clonidine on habituation and sensitization of acoustic startle in normal, decerebrate and locus coeruleus lesioned rats. Psychopharmacology 51:243–253
Davis M, Redmond DE, Baraban JM (1979) Noraderenergic agonists and antagonists: effects on conditioned fear as measured by the potentiated startle paradigm. Psychopharmacology 65:111–118
Davis M, Hitchcock J, Rosen J (1987) Anxiety and the amygdala: pharmacological and anatomical analysis of the fear potentiated startle paradigm. In: Bower GH (ed) Psychology of learning and motivation vol. 21. Academic Press, New York, pp 263–305
Davis M, Commissaris RL, Young S, Wagner KR, Kehne JH, Cassella JV, Boulis NM (1989) Spinal vs supraspinal sites of action of the alpha2 adrenergic agonists clonidine and ST-91 on the acoustic startle reflex. Pharmacol Biochem Behav 33:233–240
Davis M, Falls WA, Campeau S, Kim M (1993) Fear-potentiated startle: a neural and pharmacological analysis. Behav Brain Res 58:175–198
Fechter LD (1974) The effect ofl-dopa, clonidine and apomorphine on the acoustic startle reaction in rats. Psychopharmacology 75:219–225
Grillon C, Ameli R, Woods SW, Merikangas K, Davis M (1991) Fear-potentiated startle in humans: effects of anticipatory anxiety on the acoustic blink reflex. Psychophysiology 28:588–595
Grillon C, Ameli R, Foot M, Davis M (1993a) Fear-potentiated startle: relationship to the level of state/trait anxiety. Biol Psychiatry 33:566–574
Grillon C, Ameli R, Merikangas K, Woods SW, Davis M (1993b) Measuring the time course of anticipatory anxiety using the fear-potentiated startle reflex. Psychophysiology 30:340–346
Leaton NL, Cassella JV (1984) The effects of clonidine, prazosin, and propranolol on short-term and long-term habituation of the acoustic startle response in rats. Pharmacol Biochem Behav 20:935–942
Matthews G, Jones DM, Chamberlain AG (1990) Refining the measurement of mood: the UWIST mood adjective checklist. Br J Psychol 81:17–42
Miserendino MJD, Davis M (1993) NMDA and non-NMDA antagonists infused into the nucleus reticularis pontis caudalis depress the acoustic startle reflex. Brain Res 623:215–222
Morgan CA, Southwick SM, Grillon C, Davis M, Crystal JH, Charney DS (1993) Yohimbine-facilitated acoustic startle reflex in humans. Psychopharmacology 110:342–346
Rosen JB, Hitchcock JM, Sananes CB, Miserendino MJD, Davis M (1991) A direct projection from the central nucleus of the amygdala to the acoustic startle pathway: antegrade and retrograde studies. Behav Neurosci 99:342–380
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Kumari, V., Cotter, P., Corr, P.J. et al. Effect of clonidine on the human acoustic startle reflex. Psychopharmacology 123, 353–360 (1996). https://doi.org/10.1007/BF02246646
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DOI: https://doi.org/10.1007/BF02246646