Dopamine release in the rat cerebellum and hippocampus: a tissue 3-methoxytyramine study.
Multiple lines of evidence indicate dopamine is a neurotransmitter or neuromodulator in the cerebellum and hippocampus. In this study, we explored the utility of 3-methoxytyramine as an index of dopamine release in these regions. We found that: (1) cerebellar and hippocampal 3-methoxytyramine levels can be measured by combined gas chromatography-mass fragmentography with negative chemical ionization; (2) basal 3-methoxytyramine accumulation rates following monoamine oxidase inhibition, but not the steady-state tissue levels, are several times lower in these regions than in the frontal cortex; (3) accumulation of 3-methoxytyramine in the hippocampus and cerebellum can be enhanced following electroconvulsive shock, but not acute haloperidol (0.4 mg/kg) treatment. We conclude that 3-methoxytyramine accumulation may be a useful index of dopamine release in the cerebellum and hippocampus, but dopamine release is regulated differently in these regions than in the frontal cortex and striatum.
Chrapusta
S J
SJ
Neuropsychiatry Branch, NIMH Neuroscience Center at St. Elizabeths, Washington, DC 20032.
Egan
M F
MF
Masserano
J M
JM
Wyatt
R J
RJ
D000818:Animals; D015415:Biomarkers; D002531:Cerebellum / Q000378:metabolism*; D004298:Dopamine / Q000031:analogs & derivatives* / Q000378:metabolism; D004597:Electroshock; D008401:Gas Chromatography-Mass Spectrometry; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D010293:Pargyline / Q000494:pharmacology; D017397:Prefrontal Cortex / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D015415:Biomarkers; D010293:Pargyline; C001746:3-methoxytyramine; D004298:Dopamine