Hallucinogenic and stimulatory amphetamine derivatives: fingerprinting DOM, DOI, DOB, MDMA, and MBDB by spectral analysis of brain field potentials in the freely moving rat (Tele-Stereo-EEG)

Abstract

Telemetric recordings of field potentials from frontal cortex, hippocampus, striatum and reticular formation of freely moving rats were analysed before and after injection of the enantiomeric hallucinogenic amphetamine derivatives R-DOB [(−)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminopropane], R-DOM [(−)-1-(2,5-dimethoxy-4-methylphenyl)-2-amino-propane] and R-DOI [(−)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropanel] as well as the nonhallucinogenic amphetamine derivatives S-MBDB [(+)-N-methyl-1-(1,3-benzodioxol-5-yl)butanamine] and S-MDMA [(+)-3,4-methylenedioxymethamphetamine] and S-(+)-amphetamine. The frequency analysis of the field potentials revealed a clearcut difference between them. The spectral patterns emerging after injection of the non-hallucinogens were characterized by a general decrease of power, the changes in the alpha₂ and delta band being the most prominent, whereas only after the application of the hallucinogenic compounds was a contrasting increase of power observed in the alpha₁ frequency band, especially in the striatum. As increases in alpha₁ power have been correlated in the same pharmacological model to serotonergic control mechanisms, the results are in line with the hypothesis that 5-HT₂ receptors, predominantly occurring in the striatum, might be involved in the hallucinogenic action of drugs.