title: Changes in aminoacidergic and monoaminergic neurotransmission in the hippocampus and amygdala of rats after ayahuasca ingestion.
abstract: OBJECTIVE
  To evaluate changes in neurotransmission induced by a psychoactive beverage ayahuasca in the hippocampus and amygdala of naive rats.
  
  
  METHODS
  The level of monoamines, their main metabolites and amino acid neurotransmitters concentrations were quantified using high performance liquid chromatography (HPLC). Four groups of rats were employed: saline-treated and rats receiving 250, 500 and 800 mg/kg of ayahuasca infusion (gavage). Animals were killed 40 min after drug ingestion and the structures stored at -80 °C until HPLC assay. The data from all groups were compared using Analysis of variance and Scheffé as post test and P < 0.05 was accepted as significant.
  
  
  RESULTS
  The results showed decreased concentrations of glycine (GLY) (0.13 ± 0.03 vs 0.29 ± 0.07, P < 0.001) and γ-aminobutyric acid (GABA) (1.07 ± 0.14 vs 1.73 ± 0.25, P < 0.001) in the amygdala of rats that received 500 of ayahuasca. Animals that ingested 800 mg/kg of ayahuasca also showed a reduction of GLY level (0.11 ± 0.01 vs 0.29 ± 0.07, P < 0.001) and GABA (0.98 ± 0.06 vs 1.73 ± 0.25, P < 0.001). In the hippocampus, increased GABA levels were found in rats that received all ayahuasca doses: 250 mg/kg (1.29 ± 0.19 vs 0.84 ± 0.21, P < 0.05); 500 mg/kg (2.23 ± 038 vs 084 ± 0.21, P < 0.05) and 800 mg/kg (1.98 ± 0.92 vs 0.84 ± 0.21, P < 0.05). In addition, an increased utilization rate of all monoamines was found in the amygdala after ayahuasca administration in doses: 250 mg/kg (noradrenaline: 0.16 ± 0.02 vs 0.36 ± 0.06, P < 0.01; dopamine: 0.39 ± 0.012 vs 2.39 ± 0.84, P < 0.001; serotonin: 1.02 ± 0.22 vs 4.04 ± 0.91, P < 0.001), 500 mg/kg (noradrenaline: 0.08 ± 0.02 vs 0.36 ± 0.06, P < 0.001; dopamine: 0.33 ± 0.19 vs 2.39 ± 0.84, P < 0.001; serotonin: 0.59 ± 0.08 vs 4.04 ± 0.91, P < 0.001) and 800 mg/kg (noradrenaline: 0.16 ± 0.04 vs 0.36 ± 0.06, P < 0.001; dopamine: 0.84 ± 0.65 vs 2.39 ± 0.84, P < 0.05; serotonin: 0.36 ± 0.02 vs 4.04 ± 0.91, P < 0.001).
  
  
  CONCLUSIONS
  Our data suggest increased release of inhibitory amino acids by the hippocampus and an increased utilization rate of monoamines by the amygdala after different doses of ayahuasca ingestion.
authors: Eduardo Ferreira de Castro-Neto, Rafael Henrique da Cunha, Telma Luciana Furtado Gouveia, Esper Abrão Cavalheiro, Débora Amado, Departamento Neurologia/Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP 04023900, Brazil.
authors: Eduardo Ferreira
authors: EF
authors: de Castro-Neto
authors: Rafael Henrique
authors: RH
authors: da Cunha
authors: Dartiu Xavier
authors: DX
authors: da Silveira
authors: Mauricio
authors: M
authors: Yonamine
authors: Telma Luciana Furtado
authors: TL
authors: Gouveia
authors: Esper Abrão
authors: EA
authors: Cavalheiro
authors: Débora
authors: D
authors: Amado
authors: Maria da Graça
authors: Mda G
authors: Naffah-Mazzacoratti
keywords: Amino Acids; Amygdala; Ayahuasca; Hippocampus; Monoamines