Yuji Wada (1), Toru Egashira (1,*), Fusako Takayama (1), Yasumitsu Yamanaka
(1), Kaori Takada (2), Hiroshi Takeda (2) and Teruhiko Matsumiya (2)
(1) Department of Pharmacology, Oita Medical University, Oita 879-5593, Japan
(2) Department of Pharmacology, Tokyo Medical College, Tokyo 160-8402, Japan
(*) To whom correspondence should be addressed.
Abstract: To study the circadian rhythm of the monoamine and metabolite contents, cerebrospinal fluid was taken from the cisterna magna through a polyethylene catheter tube every 4 hr in the conscious rat. Norepinephrine and 3-methoxy-4-hydroxy-phenylglycol were found to describe a rhythm with the maximal content occurring during the dark phase and the minimal content occurring during the light phase. Dopamine levels increased significantly during the light phase compared with the dark phase. These results, given that cerebrospinal fluid can be taken chronically from conscious rats, indicate that our present method may be suitable for estimating changes in brain monoamine and metabolite contents.
Keywords: Cerebrospinal fluid, Monoamine, Rhythm