Effect of cocaine sensitization on alpha(1)-adrenoceptors in brain regions of the rat: an autoradiographic analysis.
Journal Title: Pharmacological Reports - Year 2006, Vol 58, Issue 6
Abstract
We investigated the effects of repeated intermittent cocaine treatment, resulting in behavioral sensitization, on the density of alpha(1)-adrenoceptors in the rat brain measured by quantitative in vitro autoradiography of [(3)H]prazosin. Animals were decapitated following a short (2 h) and long (48 h) withdrawal period after an injection of cocaine (10 mg/kg) on day 10 given to either cocaine-naive (saline daily, days 1-5) or cocaine-sensitized (cocaine 10 mg/kg daily, days 1-5) rats. In cocaine-naive rats, significant decreases in alpha(1)-adrenoceptors 2 h after a single dose of cocaine were observed in the amygdaloid nuclei and hippocampus; the decreases in the centromedial nucleus of the amygdala persisted until 48th hour of withdrawal. On the contrary, increases in alpha(1)-adrenoceptors after 2-h withdrawal were seen in the nucleus accumbens core and retrosplenial cortex. In cocaine-sensitized rats, the density of alpha(1)-adrenoceptors 2 h after the challenge with cocaine increased in the centrolateral amygdala, while in the granular retrosplenial cortex and in the most of thalamic nuclei, the densities of alpha(1)-adrenoceptors decreased. After 48-h withdrawal, the density of alpha(1)-adrenoceptors increased in the nucleus accumbens core and shell (by 21% and 58%, respectively), and in the amygdaloid centromedial and basolateral nuclei (by ca. 24%), while the decline was still observed in some thalamic nuclei. Our study shows for the first time that cocaine sensitization produces significant (dependent on the withdrawal time) alterations in the alpha(1)-adrenoceptor density, and the changes in some parts of the thalamus seem to be related to processes of cocaine relapses.
Authors and Affiliations
Irena Nalepa, Tadeusz Witarski, Marta Kowalska, Małgorzata Filip, Jerzy Vetulani
Keywords
Related Articles
- EP ID EP154646
- DOI -
- Views 96
- Downloads 0
Epicutaneous immunization with hapten-conjugated protein antigen alleviates contact sensitivity mediated by three different types of effector cells.
Background: Allergic contact dermatitis (ACD) is a common clinical condition in industrialized countries and often causes occupational diseases. Animal model of contact sensitivity (CS) is commonly used to study ACD in m...
Effect of licofelone against mechanical hyperalgesia and cold allodynia inthe rat model of incisional pain.
Hyperalgesia from an incisional pain is evoked by noxious stimuli (mechanicaland cold). The present study was aimed to examine the effect of licofelone, a dual inhibitor of cyclooxygenases(COX-1/COX-2) and 5-lipoxygenase...
Comparative effects of short-term and long-term insulin-induced hypoglycemia on glucose production in the perfused livers of weaned rats.
The liver glucose production (LGP) levels of 15-h overnight fasted weaned rats submitted to short-term insulin-induced hypoglycemia (ST-IIH) and long-term IIH (LT-IIH) were compared. Experiments to characterize ST-IIH or...
2-Methyl-6-phenylethynyl-pyridine (MPEP), a non-competitive mGluR5 antagonist, differentially affects the anticonvulsant activity of four conventional antiepileptic drugs against amygdala-kindled seizures in rats.
2-Methyl-6-phenylethynyl-pyridine (MPEP), a selective noncompetitive mGluR5 antagonist, influences the action of conventional antiepileptic drugs in amygdala-kindled seizures in rats. MPEP alone (up to 40 mg/kg) did not...
Amifostine improves hemodynamic parameters in doxorubicin-pretreated rabbits.
Amifostine reduces nephrotoxicity and myelotoxicity of alkylating agents. Little is known about its role in preventing cardiotoxicity. We studied if amifostine could affect the hemodynamic parameters in doxorubicin-pretr...