title: Pharmacological and behavioral characterization of the 5-HT2A receptor in C57BL/6N mice.
abstract: BACKGROUND
  The serotonin (5-HT) 2A receptor is implicated in numerous psychiatric disorders, making it an important, clinically relevant target. Despite the availability of transgenic mouse lines, the native mouse 5-HT(2A) receptor is not well-characterized.
  
  
  OBJECTIVE
  The goals of the current study were to determine 5-HT(2A) and 5-HT(2C) receptor densities in mouse cortex, establish a pharmacological profile of the mouse 5-HT(2A) receptor, and determine the effects of chronic drug treatment on 5-HT(2A) receptor density and 5-HT(2A) receptor-mediated behavior.
  
  
  METHODS
  Receptor densities were determined in cortex and frontal cortex via saturation binding assays using [(3)H]ketanserin or [(3)H]mesulergine. A pharmacological profile was established by displacing [(3)H]ketanserin binding with several ligands. Chronic treatment with 5-HT(2A/2C) receptor agonist, 2,5-dimethoxy-4-iodoamphetamine (DOI), 5-HT(2A) receptor antagonist, MDL 11939, or vehicle was followed by 5-HT(2A) receptor density determination. Head twitch responses (HTRs) were counted on select days.
  
  
  RESULTS
  Mice had high 5-HT(2A), but low 5-HT(2C) receptor densities. Ligand binding affinities for mouse 5-HT(2A) receptors correlated with rat, but not rabbit or human, affinities. Chronically DOI-treated mice displayed reduced HTRs and 5-HT(2A) receptor density compared to saline-treated mice. Receptor density was unchanged following chronic treatment with MDL 11939.
  
  
  CONCLUSIONS
  The current study provides some basic information about mouse 5-HT(2A) and 5-HT(2C) receptors and provides comparisons to rats, rabbits, and humans. The current chronic agonist treatment study demonstrated an important similarity between the 5-HT(2A) receptor in mice, rats, and rabbits, while antagonist treatment revealed an interesting difference from previous studies in rabbits.
authors.affiliation: Drexel University College of Medicine, Philadelphia, PA 19102, USA. jpd58@drexel.edu
authors.forename: John P
authors.initials: JP
authors.lastname: Dougherty
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Aloyo
mesh_terms: D000662:Amphetamines / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D002540:Cerebral Cortex / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010880:Piperidines / Q000008:administration & dosage / Q000494:pharmacology; D011485:Protein Binding; D011817:Rabbits; D051381:Rats; D017207:Rats, Sprague-Dawley; D044402:Receptor, Serotonin, 5-HT2A / Q000187:drug effects / Q000378:metabolism*; D044405:Receptor, Serotonin, 5-HT2C / Q000187:drug effects / Q000378:metabolism*; D012702:Serotonin Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D013045:Species Specificity
chemical_list: D000662:Amphetamines; D008024:Ligands; D010880:Piperidines; D044402:Receptor, Serotonin, 5-HT2A; D044405:Receptor, Serotonin, 5-HT2C; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; C066169:alpha-phenyl-1-(2-phenylethyl)-4-piperidinemethanol; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine