Dinamics of the Brain Self-stimulation after Forced Administration of Psychoactive Drugs

Shabanov PD, Lebedev AA, Lyubimov AV, Kornilov VA. [Dinamics of the Brain Self-stimulation after Forced Administration of Psychoactive Drugs]. Psychopharmacol Biol Narcol. 2009; 9(1-2). Epub 2009 May 04. Russian.
Wistar rats with implanted into the lateral hypothalamus electrodes received within 4 days i.p. the following drugs in elevated doses: 1) physiological saline (control; 0.1-0.2-0.4-0.8 ml/rat), 2) psychostimulant amphetamine (0.5-1.0-2.0-4.0 mg/kg); 3) opioid fentanyl (0.00625-0.0125-0.025-0.05 mg/kg), 4) ethanol 40% solution (0.5-1.0-2.0-4.0 g/kg), 5) barbiturate sodium ethaminal (2.5-5-10-20 mg/kg) or 6) synthetic glucocorticoid dexamethasone (0.5-1.0-2.0-4.0 mg/kg). The forced regimen of drug administration led to gradual load of the organism and prevented drug tolerance. The self-stimulation reaction of the lateral hypothalamus was registered every day within drug administration. The forced (in elevated doses) administration of psychoactive drugs revealed the following regularity: firstly, the dose-dependent effect of psychostimulant amphetamine and opioid fentanyl; secondly, dexamethasone modulated self-stimulation, increasing (2 day, 1 mg/kg) or decreasing it (3 day, 2 mg/kg); thirdly, ethanol (1-2 g/kg) activated self-stimulation slightly. At last, sodium ethaminal slightly inhibited self-stimulation and increased the thresholds of self-stimulation. Therefore, self-stimulation reaction is suitable method to evaluate the reinforcing properties of drugs after their forced administration. [in Russian with English Summary].
Citation: Psychopharmacol Biol Narcol. 2009; 9 (1-2): 2524-2529

forced narcotization, narcogenic, self-stimulation, amphetamine, fentanyl, sodium ethaminal, ethanol, dexamethasone