title: Alpha1-Adrenoceptor Antagonists Improve Memory by Activating N-methyl-D-Aspartate-Induced Ion Currents in the Rat Hippocampus.
abstract: OBJECTIVE
  Alpha1 (α1)-adrenoceptor antagonists are widely used to treat lower urinary tract symptoms. These drugs not only act on peripheral tissues, but also cross the blood-brain barrier and affect the central nervous system. Therefore, α1-adrenoceptor antagonists may enhance brain functions. In the present study, we investigated the effects of tamsulosin, an α1-adrenoceptor antagonist, on short-term memory, as well as spatial learning and memory, in rats.
  
  
  METHODS
  The step-down avoidance test was used to evaluate short-term memory, and an eight-arm radial maze test was used to evaluate spatial learning and memory. TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling) staining was performed in order to evaluate the effect of tamsulosin on apoptosis in the hippocampal dentate gyrus. Patch clamp recordings were used to evaluate the effect of tamsulosin on ionotropic glutamate receptors, such as N-methyl-D-aspartate (NMDA), amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA), and kainate receptors, in hippocampal CA1 neurons.
  
  
  RESULTS
  Tamsulosin treatment improved short-term memory, as well as spatial learning and memory, without altering apoptosis. The amplitudes of NMDA-induced ion currents were dose-dependently increased by tamsulosin. However, the amplitudes of AMPA- and kainate-induced ion currents were not affected by tamsulosin.
  
  
  CONCLUSIONS
  Tamsulosin enhanced memory function by activating NMDA receptor-mediated ion currents in the hippocampus without initiating apoptosis. The present study suggests the possibility of using tamsulosin to enhance memory under normal conditions, in addition to its use in treating overactive bladder.
authors.affiliation: Department of Urology, Gachon University Gil Medical Center, Gachon University School of Medicine, Incheon, Korea.
authors.forename: Chang Hee
authors.identifier: 0000-0002-3901-0295
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Il Gyu
authors.initials: IG
authors.lastname: Ko
authors.affiliation: Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Sung Eun
authors.initials: SE
authors.lastname: Kim
authors.affiliation: Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Mal Soon
authors.initials: MS
authors.lastname: Shin
authors.affiliation: Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Yeon Ho
authors.initials: YH
authors.lastname: Kang
authors.affiliation: Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Jung Wan
authors.initials: JW
authors.lastname: Cho
authors.affiliation: Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Key Moon
authors.initials: KM
authors.lastname: Shin
authors.affiliation: Department of Physiology, College of Medicine, Kyung Hee University, Seoul, Korea.
authors.forename: Chang Ju
authors.initials: CJ
authors.lastname: Kim
authors.affiliation: Division of Leisure & Sports Science, Department of Exercise Prescription, Dongseo University, Busan, Korea.
authors.forename: Baek Vin
authors.initials: BV
authors.lastname: Lim
authors.affiliation: Department of Urology, Gachon University Gil Medical Center, Gachon University School of Medicine, Incheon, Korea.
authors.forename: Khae Hawn
authors.identifier: 0000-0002-7045-8004
authors.initials: KH
authors.lastname: Kim
keywords: Apoptosis; Memory; Patch-Clamp Techniques; Receptors, N-methyl-D-aspartate; Tamsulosin