title: Sex- and SERT-mediated differences in stimulated serotonin revealed by fast microdialysis.
abstract: In vivo microdialysis is widely used to investigate how neurotransmitter levels in the brain respond to biologically relevant challenges. Here, we combined recent improvements in the temporal resolution of online sampling and analysis for serotonin with a brief high-K(+) stimulus paradigm to study the dynamics of evoked release. We observed stimulated serotonin overflow with high-K(+) pulses as short as 1 min when determined with 2-min dialysate sampling in ventral striatum. Stimulated serotonin levels in female mice during the high estrogen period of the estrous cycle were similar to serotonin levels in male mice. By contrast, stimulated serotonin overflow during the low estrogen period in female mice was increased to levels similar to those in male mice with local serotonin transporter (SERT) inhibition. Stimulated serotonin levels in mice with constitutive loss of SERT were considerably higher yet, pointing to neuroadaptive potentiation of serotonin release. When combined with brief K(+) stimulation, fast microdialysis reveals dynamic changes in extracellular serotonin levels associated with normal hormonal cycles and pharmacologic vs genetic loss of SERT function.
authors.forename: Hongyan
authors.initials: H
authors.lastname: Yang
authors.forename: Maureen M
authors.initials: MM
authors.lastname: Sampson
authors.forename: Damla
authors.initials: D
authors.lastname: Senturk
authors.forename: Anne M
authors.initials: AM
authors.lastname: Andrews
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002408:Catheters, Indwelling; D002412:Cations / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004967:Estrogens / Q000378:metabolism; D030762:Estrous Cycle / Q000378:metabolism; D005260:Female; D008297:Male; D057507:Mice, 129 Strain; D018345:Mice, Knockout; D017551:Microdialysis; D011188:Potassium / Q000378:metabolism; D011897:Random Allocation; D012701:Serotonin / Q000378:metabolism*; D050486:Serotonin Plasma Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D012727:Sex Characteristics
chemical_list: D002412:Cations; D004967:Estrogens; D050486:Serotonin Plasma Membrane Transport Proteins; C493231:Slc6a4 protein, mouse; D012701:Serotonin; D011188:Potassium
keywords: K+-stimulated overflow; Mice; escitalopram; serotonin transporter; sex difference