Effect of prefrontal cooling on levels of glutamate, DOPAC and 5-HIAA in nucleus accumben and striatum in vivo.
The effect of pre-frontal cooling of the cortex (PFC) on monoaminergic metabolites (DOPAC and 5-HIAA) and excitatory amino acids (glutamate (Glu) and aspartate (Asp)) was investigated using microdialysis in rat striatum (Str) and nucleus accumben (NuAc). The cooling profoundly decreased Glu and elevated DOPAC and 5-HIAA in both Str and NuAc for a long period of time. However, the time course of the detection of each compound appeared different between Str and NuAc. In NuAc, Glu decreased rapidly to reach the plateau in about 30 min; however, in Str, Glu decreased steadily and reached the plateau in about 60 min. The time courses of elevation of 5-HIAA and DOPAC were also quite different between Str and NuAc; there was more profound change observed in Str than in NuAc. The level of DOPAC exhibited a similar period of increase (7.14 min) in NuAc and Str but in NuAc it decreased toward the baseline much earlier (about 2h) than Str (over 3 h). The level of 5-HIAA in Str showed a period of rapid increase to a plateau (less than 42 min) but a trend of decrease started before the termination of sampling. In NuAc, in contrast, 5-HIAA increased slowly (more than 48 min) and maintained a plateau until termination of sampling. We conclude that PFC cooling may have caused an increase in Glu secretion and resulted in the release of the tonic restraint on DA terminals in both Str and NuAc, thus increases the synaptic turnover of monoamines.(ABSTRACT TRUNCATED AT 250 WORDS)
Wu
W H
WH
Department of Physiology and Biophysics, National Defense Medical Center, Taipei, Taiwan, Republic of China.
Hwang
N G
NG
Tseng
C J
CJ
Yin
T H
TH
Tung
C S
CS
D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis*; D000818:Animals; D003080:Cold Temperature; D003342:Corpus Striatum / Q000737:chemistry*; D005971:Glutamates / Q000032:analysis*; D018698:Glutamic Acid; D006897:Hydroxyindoleacetic Acid / Q000032:analysis*; D008297:Male; D009714:Nucleus Accumbens / Q000737:chemistry*; D017397:Prefrontal Cortex / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000502:physiology
D005971:Glutamates; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D018698:Glutamic Acid; D006897:Hydroxyindoleacetic Acid