title: Changes in Muscarinic M2 Receptor Levels in the Cortex of Subjects with Bipolar Disorder and Major Depressive Disorder and in Rats after Treatment with Mood Stabilisers and Antidepressants.
abstract: BACKGROUND
  Increasingly, data are implicating muscarinic receptors in the aetiology and treatment of mood disorders. This led us to measure levels of different muscarinic receptor-related parameters in the cortex from people with mood disorders and the CNS of rats treated with mood stabilisers and antidepressant drugs.
  
  
  METHODS
  We measured [(3)H]AF-DX 384 binding in BA 46 and BA 24 from subjects with bipolar disorders (n = 14), major depressive disorders (n = 19), as well as age- and sex-matched controls (n = 19) and the CNS of rats treated with fluoxetine or imipramine. In addition, we used Western blots to measure levels of CHRM2 protein and oxotremorine-M stimulated [(35)S]GTPγS binding as a measure of CHRM 2 / 4 signaling.
  
  
  RESULTS
  Compared with controls, [(3)H]AF-DX 384 binding was lower in BA 24 and BA 46 in bipolar disorders and major depressive disorders, while CHRM2 protein and oxotremorine-M stimulated [(35)S]GTPγS binding was only lower in BA 24. Compared with vehicle, treatment with mood stabilisers, antidepressant drugs for 10 days, or imipramine for 28 days resulted in higher levels of in [(3)H]AF-DX 384 binding select regions of rat CNS.
  
  
  CONCLUSIONS
  Our data suggest that levels of CHRM2 are lower in BA 24 from subjects with mood disorders, and it is possible that signalling by that receptor is also less in this cortical region. Our data also suggest increasing levels of CHRM2 may be involved in the mechanisms of action of mood stabilisers and tricyclic antidepressants.
authors.affiliation: Molecular Psychiatry Laboratories, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean); Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean).
authors.forename: Andrew Stuart
authors.initials: AS
authors.lastname: Gibbons
authors.affiliation: Molecular Psychiatry Laboratories, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean); Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean).
authors.forename: Won Je
authors.initials: WJ
authors.lastname: Jeon
authors.affiliation: Molecular Psychiatry Laboratories, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean); Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean).
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Scarr
authors.affiliation: Molecular Psychiatry Laboratories, Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean); Department of Psychiatry, The University of Melbourne, Parkville, Victoria, Australia (Drs Gibbons, Jeon, Scarr, and Dean).
authors.forename: Brian
authors.initials: B
authors.lastname: Dean
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000494:pharmacology* / Q000627:therapeutic use; D018692:Antimanic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001714:Bipolar Disorder / Q000188:drug therapy / Q000378:metabolism*; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D003865:Major Depressive Disorder / Q000188:drug therapy / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D005473:Fluoxetine / Q000494:pharmacology; D006801:Humans; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D018721:Muscarinic Agonists / Q000494:pharmacology; D010095:Oxotremorine / Q000031:analogs & derivatives / Q000494:pharmacology; D010890:Pirenzepine / Q000031:analogs & derivatives; D019275:Radiopharmaceuticals; D017207:Rats, Sprague-Dawley; D043585:Receptor, Muscarinic M2 / Q000378:metabolism*; D014316:Tritium
chemical_list: D000928:Antidepressive Agents; D018692:Antimanic Agents; D018721:Muscarinic Agonists; D019275:Radiopharmaceuticals; D043585:Receptor, Muscarinic M2; D005473:Fluoxetine; D014316:Tritium; C065959:AFDX 384; D010890:Pirenzepine; D010095:Oxotremorine; C042743:oxotremorine M; D007099:Imipramine
keywords: Cortex; bipolar disorders; lithium; major depressive disorders; muscarinic receptors