title: Prefrontal cortex Homer expression in an animal model of attention-deficit/hyperactivity disorder.
abstract: BACKGROUND
  Attention-deficit/hyperactivity disorder (ADHD) is a pervasive neurobehavioral disorder affecting approximately 5% of children and adolescents and 3% of adults, and the prefrontal cortex (PFC) may play the most critical role in the expression of ADHD. Converging previous studies indicate a potential role of Homer--a scaffolding protein family localized at the postsynaptic density (PSD) of glutamatergic excitatory synapses--in behavioral pathologies associated with neuropsychiatric disorders. Accordingly, we speculate that these Homer isoforms might contribute to the etiology and development of ADHD.
  
  
  METHODS
  We investigated the differential mRNA and protein expressions of several Homer isoforms in the PFC of the spontaneous hypertensive rat/Wistar-Kyoto rats (SHR/WKY), the most frequently used animal model of ADHD, using RT-PCR and western blotting. Furthermore, we examined the effects of methylphenidate (MPH) exposure on the behaviors and the expression of different Homer isoforms in the PFC of SHR, using Làt maze, RT-PCR and western blotting, respectively.
  
  
  RESULTS
  Homer 1a and Homer 2a/b, but not Homer 1b/c, were expressed at a significantly lower levels in the PFC of SHR compared with WKY. MPH exposure decreased the locomotor activity and non-selective attention of SHR, and it up regulated the expression of Homer 1a and Homer 2a/b, but not Homer 1b/c, in the PFC of SHR.
  
  
  CONCLUSIONS
  It is plausible that Homer 1a and Homer 2a/b may be involved in the etiology and pathogenesis of ADHD. Future work will focus on elucidating the specific mechanisms of Homer 1a and Homer 2a/b in ADHD.
authors.affiliation: Department of Pediatrics, Nanjing Maternity and Child Health Hospital of Nanjing Medical University, Nanjing 210004, China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Hong
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Xiao-qin
authors.initials: XQ
authors.lastname: Pan
authors.forename: Mei
authors.initials: M
authors.lastname: Guo
authors.forename: Fei
authors.initials: F
authors.lastname: Li
authors.forename: Mei-ling
authors.initials: ML
authors.lastname: Tong
authors.forename: Rong-hua
authors.initials: RH
authors.lastname: Chen
authors.forename: Xi-rong
authors.initials: XR
authors.lastname: Guo
authors.forename: Xia
authors.initials: X
authors.lastname: Chi
mesh_terms: D000818:Animals; D001289:Attention Deficit Disorder with Hyperactivity / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D000697:Central Nervous System Stimulants / Q000494:pharmacology / Q000627:therapeutic use; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D000072233:Homer Scaffolding Proteins; D008774:Methylphenidate / Q000494:pharmacology / Q000627:therapeutic use; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D020033:Protein Isoforms / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002352:Carrier Proteins; D000697:Central Nervous System Stimulants; D000072233:Homer Scaffolding Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; D008774:Methylphenidate