Controlled cortical impact injury influences methylphenidate-induced changes in striatal dopamine neurotransmission.
Traumatic brain injury features deficits are often ameliorated by dopamine (DA) agonists. We have previously shown deficits in striatal DA neurotransmission using fast scan cyclic voltammetry after controlled cortical impact (CCI) injury that are reversed after daily treatment with the DA uptake inhibitor methylphenidate (MPH). The goal of this study was to determine how a single dose of MPH (5 mg/kg) induces changes in basal DA and metabolite levels and with electrically evoked overflow (EO) DA in the striatum of CCI rats. MPH-induced changes in EO DA after a 2-week daily pre-treatment regime with MPH was also assessed. There were no baseline differences in basal DA or metabolite levels. MPH injection significantly increased basal [DA] output in dialysates for control but not injured rats. Also, MPH injection increased striatal peak EO [DA] to a lesser degree in CCI (176% of baseline) versus control rats (233% of baseline). However, daily pre-treatment with MPH resulted in CCI rats having a comparable increase in EO [DA] after MPH injection when compared with controls. The findings further support the concept that daily MPH therapy restores striatal DA neurotransmission after CCI.
Wagner
Amy K
AK
Department Physical Medicine and Rehabilitation, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA. wagnerak@upmc.edu
Sokoloski
Joshua E
JE
Chen
Xiangbai
X
Harun
Rashed
R
Clossin
Damian P
DP
Khan
Amina S
AS
Andes-Koback
Meghan
M
Michael
Adrian C
AC
Dixon
C Edward
CE
D000818:Animals; D001930:Brain Injuries / Q000188:drug therapy* / Q000503:physiopathology*; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology* / Q000503:physiopathology; D004298:Dopamine / Q000502:physiology*; D004563:Electrochemistry; D008297:Male; D008774:Methylphenidate / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
D008774:Methylphenidate; D004298:Dopamine