Effects of single and repeated administration of methamphetamine or morphine on neuroglycan C gene expression in the rat brain.
The rearrangement of neural networks associated with the behavioural sensitization and tolerance induced by psychostimulants is poorly understood. We have investigated the effects of repeated administration of methamphetamine (chronic MAP), which induces behavioural sensitization, or morphine (chronic morphine), which induces tolerance to its antinociceptive effect, on the mRNA levels of neural network-related genes in the rat brain. A gene of special interest was that for neuroglycan C (NGC), a neural tissue-specific transmembrane chondroitin sulphate proteoglycan. Single MAP (acute MAP) administration significantly decreased NGC mRNA levels in the frontal cortex, ventral tegmental area (VTA), and amygdala compared to vehicle-treated groups. Repeated MAP (chronic MAP) administration significantly increased NGC mRNA levels in the frontal cortex, nucleus accumbens (NAc), striatum, hippocampus, VTA, and amygdala compared to acute MAP treatment. Single morphine (acute morphine) administration significantly increased NGC mRNA levels in the NAc, striatum, hippocampus, VTA, and amygdala compared to vehicle-treated groups. Chronic morphine administration significantly decreased NGC mRNA levels in the NAc, striatum, VTA, and amygdala compared to acute treatment. In addition, the NGC protein level in the NAc was increased after chronic MAP and acute morphine treatment. Dopamine and opioid receptor antagonists attenuated the effect of MAP and morphine respectively on NGC mRNA levels. These results suggest that the sensitization to MAP is associated with up-regulation of NGC gene expression, while the tolerance to the morphine-induced analgesic effect is associated with the down-regulation of NGC gene expression.
Ishikawa
Kazuhiro
K
Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8560, Japan.
Nitta
Atsumi
A
Mizoguchi
Hiroyuki
H
Mohri
Akihiro
A
Murai
Rina
R
Miyamoto
Yoshiaki
Y
Noda
Yukihiro
Y
Kitaichi
Kiyoyuki
K
Yamada
Kiyofumi
K
Nabeshima
Toshitaka
T
D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000235:genetics; D008694:Methamphetamine / Q000008:administration & dosage*; D009020:Morphine / Q000008:administration & dosage*; D011509:Proteoglycans / Q000096:biosynthesis* / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar
C485738:Cspg5 protein, rat; D008565:Membrane Proteins; D011509:Proteoglycans; D008694:Methamphetamine; D009020:Morphine