Posted by JohnX2 on March 25, 2002, at 7:01:30
In reply to resens d1 receptors by a1 agonists? (SLS,et,al), posted by JohnX2 on March 25, 2002, at 3:54:36
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8097162&dopt=AbstractEur J Pharmacol 1993 Mar 16;233(1):79-84 Related Articles, Books, LinkOut
Prazosin modulates the firing pattern of dopamine neurons in rat ventral tegmental area.Grenhoff J, Svensson TH.
Department of Pharmacology, Karolinska Institutet, Stockholm, Sweden.
Previous studies have indicated a noradrenergic modulation of midbrain dopamine cell activity. The effects of systemic administration of the alpha 1-adrenoceptor antagonist prazosin and the alpha 2-antagonist idazoxan on midbrain dopamine cell firing were now studied with extracellular recording from single dopamine neurons in the ventral tegmental area of chloral hydrate-anaesthetized male rats. Prazosin (0.15-0.6 mg/kg i.v.) dose dependently decreased burst firing and regularized the firing pattern of dopamine neurons, while the firing rate was unaffected. The prazosin-induced effects were abolished by pretreatment with reserpine. Idazoxan (0.5-2.0 mg/kg i.v.) increased firing rate and burst firing and made the firing pattern less regular, probably by increasing adrenergic transmission via blockade of presynaptic alpha 2-adrenoceptors. The effects of idazoxan were blocked by prazosin. The present results indicate that noradrenergic neurons modulate the dopamine cell firing pattern via excitatory postsynaptic alpha 1-adrenoceptors. This mechanism might be involved in the pathogenesis and pharmacological treatment of schizophrenia.
PMID: 8097162 [PubMed - indexed for MEDLINE]
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