TY - JOUR
T1 - Shift from inhibition to excitation in the neostriatum but not in the nucleus accumbens following long-term amphethamine
AU - Alloway, Kevin D.
AU - Rebec, George V.
N1 - Funding Information:
This researchw as supportedb y USPHS Grant DA-02451a wardedto G.V.R. The authorsw ish to thankD rs. Andrew G. Ewing, StevenD . Curtis and R. Mark Wightmanfo r helpfula dvicew ith the cate-cholaminaen alysisW. e also acknowledgMes . Doris Harrisf or preparintgh eh istologicasle ctionas ndMs. SuzanneH ull for preparingth e illustrationsS. mith, Kline, and Frenchs uppliedt heD -amphetaminseul - fate.
PY - 1983/8/22
Y1 - 1983/8/22
N2 - Neuronal responses to 1.0 or 5.0 mg/kg d-amphetamine were recorded simultaneously in the neostriatum and nucleus accumbens of rats pretreated twice daily with these doses or with saline for 6 consecutive days. In all groups, the number of neurons responding to a challenge injection of either dose of amphetamine with an overall excitation or inhibition was not significantly different. During the first 30-60 min of the drug response, however, neurons in the neostriatum of amphetamine-pretreated rats responded with a significant increase in firing rate compared to saline controls. In the nucleus accumbens, on the other hand, tolerance developed to the inhibition produced by 1.0 mg/kg d-amphetamine, whereas the responses produced by 5.0 mg/kg were not significantly altered by long-term treatment. Liquid chromatography with electrochemical detection revealed that pretreatment with 5.0 mg/kg d-amphetamine produced a slight, but significant, reduction of dopamine and norepinephrine levels in the neostriatum. Catecholamine levels were not significantly altered in the nucleus accumbens by either dose. These electrophysiological and neurochemical changes are discussed in relation to the known involvement of these sites in the dose-dependent behavioral alterations that accompany repeated amphetamine injections.
AB - Neuronal responses to 1.0 or 5.0 mg/kg d-amphetamine were recorded simultaneously in the neostriatum and nucleus accumbens of rats pretreated twice daily with these doses or with saline for 6 consecutive days. In all groups, the number of neurons responding to a challenge injection of either dose of amphetamine with an overall excitation or inhibition was not significantly different. During the first 30-60 min of the drug response, however, neurons in the neostriatum of amphetamine-pretreated rats responded with a significant increase in firing rate compared to saline controls. In the nucleus accumbens, on the other hand, tolerance developed to the inhibition produced by 1.0 mg/kg d-amphetamine, whereas the responses produced by 5.0 mg/kg were not significantly altered by long-term treatment. Liquid chromatography with electrochemical detection revealed that pretreatment with 5.0 mg/kg d-amphetamine produced a slight, but significant, reduction of dopamine and norepinephrine levels in the neostriatum. Catecholamine levels were not significantly altered in the nucleus accumbens by either dose. These electrophysiological and neurochemical changes are discussed in relation to the known involvement of these sites in the dose-dependent behavioral alterations that accompany repeated amphetamine injections.
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U2 - 10.1016/0006-8993(83)91096-X
DO - 10.1016/0006-8993(83)91096-X
M3 - Article
C2 - 6616234
AN - SCOPUS:0020564199
SN - 0006-8993
VL - 273
SP - 71
EP - 79
JO - Brain research
JF - Brain research
IS - 1
ER -