title: Sodium depletion and aldosterone decrease dopamine transporter activity in nucleus accumbens but not striatum.
abstract: Motivated behaviors, including sodium (Na) appetite, are correlated with increased dopamine (DA) transmission in the nucleus accumbens (NAc). DA transporter (DAT) modulation affects DA transmission and may play a role in motivated behaviors. In vivo Na depletion, which reliably induces Na appetite, was correlated with robust decreases in DA uptake via the DAT in the rat NAc with rotating disk electrode voltammetry [1,277 +/- 162 vs. 575 +/- 89 pmol. s-1. g-1; Vmax of transport for control vs. Na-depleted tissue]. Plasma aldosterone (Aldo) levels increase after in vivo Na depletion and contribute to Na appetite. Decreased DAT activity in the NAc was observed after in vitro Aldo treatment (428 +/- 28 vs. 300 +/- 25 pmol. s-1. g-1). Neither treatment affected DAT activity in the striatum. These results suggest that a direct action of Aldo is one possible mechanism by which Na depletion induces a reduction in DAT activity in the NAc. Reduced DAT activity may play a role in generating increased NAc DA transmission during Na appetite, which may underlie the motivating properties of Na for the Na-depleted rat.
authors.affiliation: Program in Neurobiology and Behavior, University of Washington, Seattle, Washington 98195, USA. roitman@u.washington.edu
authors.forename: M F
authors.initials: MF
authors.lastname: Roitman
authors.forename: T A
authors.initials: TA
authors.lastname: Patterson
authors.forename: R R
authors.initials: RR
authors.lastname: Sakai
authors.forename: I L
authors.initials: IL
authors.lastname: Bernstein
authors.forename: D P
authors.initials: DP
authors.lastname: Figlewicz
mesh_terms: D000450:Aldosterone / Q000378:metabolism*; D000818:Animals; D001066:Appetite / Q000502:physiology; D002352:Carrier Proteins / Q000378:metabolism*; D003342:Corpus Striatum / Q000378:metabolism*; D004232:Diuretics / Q000494:pharmacology; D004298:Dopamine / Q000493:pharmacokinetics; D050483:Dopamine Plasma Membrane Transport Proteins; D005665:Furosemide / Q000494:pharmacology; D006982:Hypertonic Solutions / Q000494:pharmacology; D007457:Iodine Radioisotopes; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009042:Motivation; D009419:Nerve Tissue Proteins; D009714:Nucleus Accumbens / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012964:Sodium / Q000172:deficiency*; D012982:Sodium, Dietary / Q000494:pharmacology
chemical_list: D002352:Carrier Proteins; D004232:Diuretics; D050483:Dopamine Plasma Membrane Transport Proteins; D006982:Hypertonic Solutions; D007457:Iodine Radioisotopes; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493216:Slc6a3 protein, rat; D012982:Sodium, Dietary; D000450:Aldosterone; D005665:Furosemide; D012964:Sodium; D004298:Dopamine