PT  - JOURNAL ARTICLE
AU  - Kota Ishida
AU  - Mikio Murata
AU  - Nobuyuki Katagiri
AU  - Masago Ishikawa
AU  - Kenji Abe
AU  - Masatoshi Kato
AU  - Iku Utsunomiya
AU  - Kyoji Taguchi
TI  - Effects of β-Phenylethylamine on Dopaminergic Neurons of the Ventral Tegmental Area in the Rat: A Combined Electrophysiological and Microdialysis Study
AID  - 10.1124/jpet.105.084764
DP  - 2005 Aug 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 916--922
VI  - 314
IP  - 2
4099  - http://jpet.aspetjournals.org/content/314/2/916.short
4100  - http://jpet.aspetjournals.org/content/314/2/916.full
SO  - J Pharmacol Exp Ther2005 Aug 01; 314
AB  - The effects of systemic administration of β-phenylethylamine (β-PEA) and microiontophoretically applied β-PEA on the spontaneous discharge of dopamine (DA) neurons in the ventral tegmental area (VTA) of the anesthetized rat were examined. Intravenous administration of β-PEA (1.0, 2.5, and 5.0 mg/kg) and microiontophoretic applications of β-PEA caused inhibitory responses in DA neurons. Systemic administration and microiontophoretic applications of β-PEA induced dose- or current-dependent responses. The systemic β-PEA-induced inhibitory responses were reversed by pretreatment with the DA D2 receptor antagonists haloperidol (0.5 mg/kg i.p.) and sulpiride (10 mg/kg i.p). Pretreatment with reserpine (5 mg/kg i.p. 24 h earlier) did not completely block the systemic administration of β-PEA (2.5 mg/kg) inhibition. A microdialysis study of freely moving rats demonstrated that the extracellular DA level increased significantly in response to local application of β-PEA (100 μM) in the VTA via a microdialysis probe, and local application of β-PEA-stimulated somatodendritic DA release in the VTA. The β-PEA-induced release of DA was calcium ion-independent and was enhanced by pretreatment with pertussis toxin. These findings indicate that β-phenylethylamine inhibits DA neuron activity via DA D2 autoreceptors in the rat VTA and that this inhibitory effect is mediated by the somatodendritic DA release. The American Society for Pharmacology and Experimental Therapeutics