Intrastriatal injection of 5,7-dihydroxytryptamine decreased 5-HT levels in the striatum and suppressed locomotor activity in C57BL/6 mice.
Effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and 5,7-dihydroxytryptamine (5,7-DHT) on striatal levels of dopamine (DA), 5-hydroxytryptamine (5-HT), and their metabolites, as well as on locomotor activity were investigated in C57BL/6 mice. The results showed that MPTP significantly increased locomotor activity and decreased striatal DA levels. However, injection of the serotonergic neurotoxin 5,7-DHT in the striatum, either alone or following high doses of MPTP, significantly decreased locomotor activity, and concomitantly decreased striatal levels of 5-HT and 5-HIAA. This study suggests that the increased locomotor activity may be due to increased striatal serotonergic activity which overcompensates for the DA deficiency. The locomotor hypoactivity, induced by 5,7-DHT, might be due to the decreased striatal levels of 5-HT and 5-HIAA.
Chia
L G
LG
Section of Neurology, Veterans General Hospital, Taichung, Taiwan.
Ni
D R
DR
Cheng
F C
FC
Ho
Y P
YP
Kuo
J S
JS
D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine / Q000494:pharmacology; D015116:5,7-Dihydroxytryptamine / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004298:Dopamine / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects*; D012701:Serotonin / Q000378:metabolism*
D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D015632:1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; D004298:Dopamine