K. Yoshimoto et al., EFFECTS OF ION-CHANNEL BLOCKERS ON RAPID POSTMORTEM CHANGES IN EXTRACELLULAR DOPAMINE AND SEROTONIN LEVELS IN THE RAT NUCLEUS-ACCUMBENS, Forensic science international, 85(1), 1997, pp. 29-39
In the present study, we used in vivo brain microdialysis to examine t
he effects of ion channel blockers tetrodotoxin (TTX), EGTA-free Ca2and verapamil on rapid post mortem changes in extracellular levels of
doapmine (DA), serotonin (5-HT) and their metabolites dihydroxyphenyla
cetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) in the ACC
of freely moving rats. Extracellular ACC DA levels decreased following
the perfusion of the three ion channel blockers in freely moving rats
, and then, at death by cervical dislocation, maximum respective 220-,
60- and 90-fold increases were observed in the extracellular output o
f DA in animals treated with EGTA, verapamil and TTX, respectively. Al
so, ACC 5-HT decreased following perfusion with the three blockers in
the freely moving rats, and then maximum increases of 80-, 30- and 45-
fold in the extracellular output of 5-HT were observed at death in ani
mals treated with EGTA, verapamil and TTX, respectively, compared to t
he baseline. Cervical dislocation-induced rapid postmortem changes wer
e inhibited markedly by perfusion with CSF containing the Ca2+ entry b
locker verapamil. These observations suggested that rapid postmortem c
hanges in ACC DA and 5-HT release were associated with the action of c
alcium ion channels and/or voltage gated channels in the CNS. (C) 1997
Elsevier Science Ireland Ltd.