The effects of a 5‐HT2 receptor antagonist (ICI 169,369) on changes in waking EEG, pupillary responses and state of arousal in human volunteers.

Comparison of ketanserin, buspirone and propranolol on arousal, pupil size and autonomic function in healthy volunteers

“…Ketanserin reduced RPD and increased the light reflex amplitude, suggesting a role of 5HT2 receptors in mediating pupil size and the light reflex. Two previous reports failed to show an effect of ketanserin on the pupil (Costagliola et al 1991;Tekat et al 2001), but the observed ketanserin-induced miosis in our study is in agreement with previously reported miotic effects of the selective 5HT2 antagonists ICI 169,369 and ICI 170,809 (Millson et al 1991;Millson et al 1992). …”

Comparison of the effects of venlafaxine, paroxetine and desipramine on the pupillary light reflex in man

“…Indeed, there is evidence that such mechanisms may be involved in pupillary control. Thus it has been reported that both 5-HT 2 receptor antagonists (Millson et al 1991(Millson et al , 1992 and 5HT 1A receptor agonists (Fanciullacci et al 1995;Phillips et al 1998) cause miosis. On the other hand, fenfluramine, a drug known to release 5HT from pre-synaptic terminals, increases pupil diameter (Kramer et al 1973).…”

Modulation of the Critical Flicker Fusion effects of serotonin reuptake inhibitors by concomitant pupillary changes

“…It has been reported that 5HT 2 receptor antagonists (Millson et al 1991(Millson et al , 1992 and 5HT 3 receptor antagonists (Rizzi et al 1993) cause miosis. In contrast, fenfluramine, m-chlorophenylpiperazine and 5-HT 1A receptor agonists were shown to increase pupil size (Benjamin et al 1997;Broocks et al 1998;Prow et al 1996).…”