Tyrosine hydroxylase activity and its mRNA level in dopaminergic neurons of tenascin gene knockout mouse.
We have recently demonstrated that some tenascin (TN) gene-knockout mice display abnormal behaviors, and that these abnormal behaviors stem from a low level of dopamine transmission in the brain. In the present study, we elucidated that tyrosine hydroxylase (TH) activity in the frontal cortex, striatum, and hippocampus of TN-knockout mice which showed abnormal behavior was significantly decreased. Also, the TH mRNA level of the midbrain was decreased by 43% in these animals compared with values for wild-type mice. These results suggest that the low dopamine turnover rate in some areas of the brain of TN-knockout mice accompanied by motor defects is due, at least in part, to the reduction in TH activity caused by diminished TH mRNA expression, and that TN-knockout mice exhibit abnormal behaviors in the presence of low levels of TH-gene expression.
Fukamauchi
F
F
Department of Molecular Medical Science, Tokyo Medical and Dental University, Japan.
Mataga
N
N
Wang
Y J
YJ
Sato
S
S
Yoshiki
A
A
Kusakabe
M
M
D000818:Animals; D015152:Blotting, Northern; D004298:Dopamine / Q000378:metabolism*; D008636:Mesencephalon / Q000201:enzymology; D051379:Mice; D018345:Mice, Knockout; D009043:Motor Activity / Q000235:genetics; D009474:Neurons / Q000201:enzymology*; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D019063:Tenascin / Q000235:genetics*; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics / Q000378:metabolism*
D012333:RNA, Messenger; D019063:Tenascin; D014446:Tyrosine 3-Monooxygenase; D004298:Dopamine