Amphetamine sensitization: Nonassociative and associative components.

Abstract

Rats, pretreated with amphetamine (AMPH, 1 mg/kg) or saline for 2 weeks, were challenged with AMPH (0.5 mg/kg) or saline following 1 week of abstinence, and locomotion was measured. In Experiments 1 and 2, the pretreatment occurred in various contexts (home cage, novel box, test box). Sensitization was observed only when pretreatment context and test context were the same; a context switch abolished sensitization. When rats anesthetized with chloral hydrate were pretreated with AMPH, sensitization was completely dependent on the pretreatment, but independent of context. This "zero context" condition isolated the basal level of excitation attributable to unconditioned neural change to determine the role of contextual input to be a modulator that enhances or inhibits sensitization.

Role of nitric oxide in amphetamine-induced sensitization of schedule-induced polydipsic rats

“…However, certain issues remain undetermined. First, AMPH sensitization can be behaviorally categorized as either contextdependent (i.e., associative) or context-independent (i.e., non-associative; Wang and Hsiao 2003), referring to context-dependent conditioning or unconditioned neuroadaptation, respectively. It is important to determine which of these mechanisms underlies the AMPH sensitization in SIP.…”

Drug Wanting: Behavioral Sensitization and Relapse to Drug-Seeking Behavior

“…The environment can influence both the initiation and expression of behavioral sensitization. Thus, animals repeatedly exposed to drugs such as cocaine, amphetamine, or morphine during the initiation phase expressed more robust sensitization when re-exposed to drug in the same environment (paired) as previous drug exposure during the expression phase, compared with animals tested in an environment that differed (unpaired) from that used during the initiation phase Anagnostaras and Robinson, 1996;Wang and Hsiao, 2003;Mattson et al, 2008;Vezina and Leyton, 2009). Behavioral sensitization in the paired environment is commonly referred to as context-dependent sensitization as opposed to con-1 Abbreviations: AMPA, ␣-amino-3-hydroxyl-5-methyl-4-isoxazolepropionate; CNQX, 6-cyano-7-nitroquinoxaline-2,3-dione; CPP, conditioned place preference; CRF, corticotropin-releasing factor; GluR, glutamate receptor; JNJ16259685, (3,4-dihydro-2H-pyrano[2,3-b] quinolin-7-yl)-(cis-4-methoxycyclohexyl)-methanone; LDT, laterodorsal tegmentum; LTP, long-term potentiation; LY341495, 2-[(1S,2S)-2-carboxycyclopropyl]-3-(9H-xanthen-9-yl)-D-alanine; LY379268, (1R,4R,5S,6R)-4-amino-2-oxabicyclo[3.1.0]hexane-4,6-dicarboxylic acid; mGluR, metabotropic glutamate receptor; mPFC, medial prefrontal cortex; NMDA, N-methyl-D-aspartate; PPT, pedunculopontine tegmentum; PVN, paraventricular nucleus; SCH23390, (R)-(ϩ)-7-chloro-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine; SKF 81297, (Ϯ)-6-chloro-7,8-dihydroxy-1-phenyl-2,3,4,5-tetrahydro-1H-3-benzazepine hydrobromide; SKF38393, 2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; SKF82958, (Ϯ)-6-chloro-7,8-dihydroxy-3-allyl-1-phenyl-2,3,4,5-tetra-hydro-1H-benzazepine; VTA, ventral tegmental area.…”

Neural Substrates of Amphetamine-Induced Behavioral Sensitization: Unconditioned (Zero Context) and Conditioned (Switch versus Same Context) Components in c-<b><i>fos</i></b> Overexpression

“…NaCl was dissolved in distilled water at a 0.15 m isotonic concentration, and AMPH was prepared in normal saline. AMPH doses of 0.5 and 1 mg/kg were used according to previous methods [27]. All intraperitoneal injections were at volumes of 1 ml/kg for AMPH and saline.…”

“…The infrared sensor of the Columbus box was used to measure the activity within the novel box. The home cage was a stainless steel hanging cage with a wire floor [27]. …”

“…This study demonstrated how to produce unconditioned, purely AMPH-induced behavioral sensitization [25]. Moreover, a microdialysis study tested the DA and norepinephrine-releasing concentrations in the medial prefrontal cortex (mPFC) under the influence of two different anesthetic drugs, chloral hydrate and pentobarbital sodium.…”