Table 2.

Findings related to sensory modulation by serotonin.

Sensory area	Species and anesthesia, if applicable	Significance	Reference
Cochlear nucleus	Urethane anesthetized rat	Mostly suppressive effect of iontophoretically applied 5HT on extracellular responses	Ebert and Ostwald, 1992
Inferior colliculus	Lightly anesthetized (ketamine/xylazine) Bat	Multiplicative decrease of response with iontophoretic 5HT application; weak increase in latency	Hurley and Pollak, 1999, 2005
Putative auditory contribution	Behaving rat	Startle response to auditory white noise is reduced by intraventricular 5HT application	Davis et al., 1980
V1	Anesthetized (isoflurane/droperidol/fentanyl) macaque	Variable bidirectional modulation of extracellular responses with application of 5HT1B and 5HT2A receptor selective agents	Watakabe et al., 2009
V1	Anesthetized (fentanyl/thiopental/succinylcholine chloride) macaque	Intracortical injection of 5HT1A agonist decreases extracellularly recorded responses	Rauch et al., 2008
V1	Behaving macaque	Gain decrease of extracellular responses with iontophoretic 5HT application. Modest increase in response latency. No systematic effect on response variability, co-variability, or selectivity	Seillier et al., 2017
V1	Halothane anesthetized rat	Variable findings for iontophoretic 5HT application but mainly a decreased response across the population	Waterhouse et al., 1990
dLGN	Halothane/nitrous oxide anesthetized cat	Decrease of the extracellular responses for iontophoretic 5HT application	Phillis et al., 1967
S1	Halothane anesthetized rat	Suppression of response to tactile stimuli (forepaw touch), consistent with response gain decrease with iontophoretic 5HT application	Waterhouse et al., 1986
	Behaving mouse	Decreased mechanosensory response of mice during optogenetic activation of serotonergic raphe neurons	Dugué et al., 2014
	Behaving macaque	Blocking serotonin re-uptake slowed reaction times and worsened perceptual performance in a visual (color) discrimination task	Costa et al., 2016
Olfactory bulb	Ketamine/xylazine anesthetized mouse	Gain decrease for application of 5HT agonists, reversed for application of 5HT antagonist.	Petzold et al., 2009
Olfactory bulb	Urethane anesthetized mouse	Optogenetic activation of serotonergic neurons in the dorsal raphe lead to a gain decrease of spontaneous but not stimulus-driven extracellular response in the OB resulting in an increase in SNR	Lottem et al., 2016