RT Journal Article
SR Electronic
T1 Effects of β-Phenylethylamine on Dopaminergic Neurons of the Ventral Tegmental Area in the Rat: A Combined Electrophysiological and Microdialysis Study
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 916
OP 922
DO 10.1124/jpet.105.084764
VO 314
IS 2
A1 Kota Ishida
A1 Mikio Murata
A1 Nobuyuki Katagiri
A1 Masago Ishikawa
A1 Kenji Abe
A1 Masatoshi Kato
A1 Iku Utsunomiya
A1 Kyoji Taguchi
YR 2005
UL http://jpet.aspetjournals.org/content/314/2/916.abstract
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