Electroencephalographic and convulsive effects of binge doses of (+)-methamphetamine, 5-methoxydiisopropyltryptamine, and (±)-3,4-methylenedioxymethamphetamine in rats.
Devon L Graham, Nicole R Herring, Tori L Schaefer, Katherine D Holland, Charles V Vorhees, Michael T Williams
The open neuropsychopharmacology journal January 1, 2012 Peer reviewed DOI: 10.2174/1876523801205010001 via PubMed
Summary
In a study of male Sprague-Dawley rats, MDMA did not cause significant EEG abnormalities or myoclonus, while methamphetamine (MA) led to myoclonic activity and brief EEG epileptiform activity in about 50% of the rats. All rats treated with Foxy experienced seizures by the second dose, indicating severe EEG abnormalities. These findings suggest that binge doses of MA increase EEG abnormalities, unlike MDMA, and that Foxy is associated with severe neurological effects.
Study at a glance
| Design | experimental study |
|---|---|
| Population | male Sprague-Dawley rats |
| Key finding | Binge doses of methamphetamine increased EEG abnormalities, while MDMA did not cause significant effects, and all rats treated with Foxy exhibited seizures. |
Abstract
The abuse of drugs such as methamphetamine (MA), 3,4-methylenedioxymethamphetamine (Ecstasy, MDMA), and 5-methoxydiisopropyltryptamine (5-MeO-DIPT; Foxy) is global. Symptoms from taking these drugs include tachycardia, agitation, hyperpyrexia, and sometimes seizures. We compared the EEG effects of these drugs in male Sprague-Dawley rats (~300 g) implanted with cortical electroencephalographic (EEG) electrodes prior to testing. Animals received four subcutaneous injections of MA, MDMA, or Foxy (10 mg/kg each as freebase, administered every 2 h), or saline as these doses produce lasting effects on learning, memory, and monoamines. EEG tracings were recorded before, during, and after treatment. Animals receiving MDMA showed no significant EEG abnormalities or myoclonus. MA treatment resulted in myoclonic activity and in brief (<10 s) EEG epileptiform activity in ~50% of the rats. Longer seizure activity (10 s to 5 min) was recorded in some MA-treated rats following the third and fourth doses. The onset of myoclonic activity following Foxy treatment occurred shortly after the first dose. All rats receiving Foxy showed seizures by the second dose and this continued throughout the treatment regimen. The results show that binge doses of MA and MDMA, which mimic the neurochemical changes seen in chronic users, increase EEG abnormalities after MA but not after MDMA. While the neurochemical effects of Foxy are not known in humans, this drug causes severe EEG abnormalities and overt seizures in 100% of tested animals.