title: Serotonergic hallucinogens differentially modify gamma and high frequency oscillations in the rat nucleus accumbens.
abstract: BACKGROUND
  The nucleus accumbens (NAc) is a site critical for the actions of many drugs of abuse. Psychoactive compounds, such as N-methyl-D-aspartate receptor (NMDAR) antagonists, modify gamma (40-90) and high frequency oscillations (HFO, 130-180 Hz) in local field potentials (LFPs) recorded in the NAc. Lysergic acid diethylamide (LSD) and 2,5-dimethoxy-4-iodoamphetamine (DOI) are serotonergic hallucinogens and activation of 5HT2A receptors likely underlies their hallucinogenic effects. Whether these compounds can also modulate LFP oscillations in the NAc is unclear.
  
  
  OBJECTIVE
  This study aims to examine the effect of serotonergic hallucinogens on gamma and HFO recorded in the NAc and to test whether 5HT2A receptors mediate the effects observed.
  
  
  METHODS
  LFPs were recorded from the NAc of freely moving rats. Drugs were administered intraperitoneally.
  
  
  RESULTS
  LSD (0.03-0.3 mg/kg) and DOI (0.5-2.0 mg/kg) increased the power and reduced the frequency of HFO. In contrast, the hallucinogens produced a robust reduction in the power of low (40-60 Hz), but not high gamma oscillations (70-90 Hz). MDL 11939 (1.0 mg/kg), a 5HT2A receptor antagonist, fully reversed the changes induced by DOI on HFO but only partially for the low gamma band. Equivalent increases in HFO power were observed after TCB-2 (5HT2A receptor agonist, 0.1-1.5 mg/kg), but not CP 809101 (5H2C receptor agonist, 0.1-3 mg/kg). Notably, hallucinogen-induced increases in HFO power were smaller than those produced by ketamine (25 mg/kg).
  
  
  CONCLUSIONS
  Serotonergic hallucinogen-induced changes in HFO and gamma are mediated, at least in part, by stimulation of 5HT2A receptors. Comparison of the oscillatory changes produced by serotonergic hallucinogens and NMDAR antagonists are also discussed.
authors.affiliation: Laboratory of the Limbic System, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland. s.goda@nencki.gov.pl
authors.forename: Sailaja A
authors.initials: SA
authors.lastname: Goda
authors.forename: Joanna
authors.initials: J
authors.lastname: Piasecka
authors.forename: Maciej
authors.initials: M
authors.lastname: Olszewski
authors.forename: Stefan
authors.initials: S
authors.lastname: Kasicki
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Hunt
mesh_terms: D000662:Amphetamines / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001643:Bridged Bicyclo Compounds / Q000008:administration & dosage / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006213:Hallucinogens / Q000008:administration & dosage / Q000494:pharmacology*; D007274:Injections, Intraperitoneal; D007649:Ketamine / Q000494:pharmacology; D008238:Lysergic Acid Diethylamide / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008744:Methylamines / Q000008:administration & dosage / Q000494:pharmacology; D009714:Nucleus Accumbens / Q000187:drug effects / Q000378:metabolism; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology; D011719:Pyrazines / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044402:Receptor, Serotonin, 5-HT2A / Q000187:drug effects* / Q000378:metabolism; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: C514172:(4-bromo-3,6-dimethoxybenzocyclobuten-1-yl)methylamine; D000662:Amphetamines; D001643:Bridged Bicyclo Compounds; C518685:CP-809,101; D006213:Hallucinogens; D008744:Methylamines; D010879:Piperazines; D011719:Pyrazines; D044402:Receptor, Serotonin, 5-HT2A; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D007649:Ketamine; D008238:Lysergic Acid Diethylamide; C015952:4-iodo-2,5-dimethoxyphenylisopropylamine