Biomaterial Database

D2-like dopamine receptor activation excites rat dorsal raphe 5-HT neurons in vitro. 2001

S Haj-Dahmane

Research Institute on Addictions, University at Buffalo, SUNY at Buffalo, 1021 Main Street, Buffalo, New York 14203, USA. dahmane@ria.buffalo.edu

The aim of the present study was to investigate the effect of dopamine (DA) on the excitability of dorsal raphe nucleus (DRN) 5-hydroxytryptamine (5-HT) neurons using the patch-clamp technique in brain slices. Bath application of DA (1-300 microM) produced a concentration-dependent membrane depolarization in all 5-HT neurons examined. This effect persisted in the presence of tetrodotoxin (TTX; 1 microM) and low extracellular calcium. Moreover, blockade of ionotropic glutamate receptors with 6,7-dinitroquinoxaline-2,3-dione (DNQX) and 2-amino-5-phosphonopentanoic acid (AP5) did not prevent DA-induced depolarization, indicating that it was mediated by a direct effect of DA on 5-HT neurons. The DA-induced depolarization was not antagonized by selective alpha1-adrenergic receptor antagonists, prazosin and WB 4101, but by a nonselective DA receptor antagonist, haloperidol. In addition, the selective D2-like receptor agonist quinpirole and antagonist sulpiride mimicked and blocked DA-induced depolarization, respectively. These results indicate that DA-induced membrane depolarization in DRN 5-HT neurons is mediated by the activation of D2-like DA receptors. The DA-induced membrane depolarization and inward current were associated with an increase in membrane conductance. Examination of the current-voltage (I-V) relationship for the DA-induced inward current revealed that the amplitude of the current increased with membrane hyperpolarization and reversed polarity at a potential near -15 mV. These data suggest that DA-induced depolarization in DRN 5-HT neurons is not mediated by a decrease in potassium conductance, but most likely by the activation of a nonselective cation current.

UI	MeSH Term	Description	Entries
D007473	Ion Channels	Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.	Membrane Channels,Ion Channel,Ionic Channel,Ionic Channels,Membrane Channel,Channel, Ion,Channel, Ionic,Channel, Membrane,Channels, Ion,Channels, Ionic,Channels, Membrane
D008297	Male		Males
D009474	Neurons	The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.	Nerve Cells,Cell, Nerve,Cells, Nerve,Nerve Cell,Neuron
D009924	Organ Culture Techniques	A technique for maintenance or growth of animal organs in vitro. It refers to three-dimensional cultures of undisaggregated tissue retaining some or all of the histological features of the tissue in vivo. (Freshney, Culture of Animal Cells, 3d ed, p1)	Organ Culture,Culture Technique, Organ,Culture Techniques, Organ,Organ Culture Technique,Organ Cultures
D011903	Raphe Nuclei	Collections of small neurons centrally scattered among many fibers from the level of the TROCHLEAR NUCLEUS in the midbrain to the hypoglossal area in the MEDULLA OBLONGATA.	Caudal Linear Nucleus of the Raphe,Interfascicular Nucleus,Nucleus Incertus,Rostral Linear Nucleus of Raphe,Rostral Linear Nucleus of the Raphe,Superior Central Nucleus,Central Nucleus, Superior,Incertus, Nucleus,Nuclei, Raphe,Nucleus, Interfascicular,Nucleus, Raphe,Nucleus, Superior Central,Raphe Nucleus
D004298	Dopamine	One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.	Hydroxytyramine,3,4-Dihydroxyphenethylamine,4-(2-Aminoethyl)-1,2-benzenediol,Dopamine Hydrochloride,Intropin,3,4 Dihydroxyphenethylamine,Hydrochloride, Dopamine
D004558	Electric Stimulation	Use of electric potential or currents to elicit biological responses.	Stimulation, Electric,Electrical Stimulation,Electric Stimulations,Electrical Stimulations,Stimulation, Electrical,Stimulations, Electric,Stimulations, Electrical
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000316	Adrenergic alpha-Agonists	Drugs that selectively bind to and activate alpha adrenergic receptors.	Adrenergic alpha-Receptor Agonists,alpha-Adrenergic Receptor Agonists,Adrenergic alpha-Agonist,Adrenergic alpha-Receptor Agonist,Receptor Agonists, Adrenergic alpha,Receptor Agonists, alpha-Adrenergic,alpha-Adrenergic Agonist,alpha-Adrenergic Agonists,alpha-Adrenergic Receptor Agonist,Adrenergic alpha Agonist,Adrenergic alpha Agonists,Adrenergic alpha Receptor Agonist,Adrenergic alpha Receptor Agonists,Agonist, Adrenergic alpha-Receptor,Agonist, alpha-Adrenergic,Agonist, alpha-Adrenergic Receptor,Agonists, Adrenergic alpha-Receptor,Agonists, alpha-Adrenergic,Agonists, alpha-Adrenergic Receptor,Receptor Agonist, alpha-Adrenergic,Receptor Agonists, alpha Adrenergic,alpha Adrenergic Agonist,alpha Adrenergic Agonists,alpha Adrenergic Receptor Agonist,alpha Adrenergic Receptor Agonists,alpha-Agonist, Adrenergic,alpha-Agonists, Adrenergic,alpha-Receptor Agonist, Adrenergic,alpha-Receptor Agonists, Adrenergic
D000317	Adrenergic alpha-Antagonists	Drugs that bind to but do not activate alpha-adrenergic receptors thereby blocking the actions of endogenous or exogenous adrenergic agonists. Adrenergic alpha-antagonists are used in the treatment of hypertension, vasospasm, peripheral vascular disease, shock, and pheochromocytoma.	Adrenergic alpha-Receptor Blockaders,alpha-Adrenergic Blocking Agents,alpha-Adrenergic Receptor Blockaders,alpha-Blockers, Adrenergic,Adrenergic alpha-Blockers,alpha-Adrenergic Antagonists,alpha-Adrenergic Blockers,Adrenergic alpha Antagonists,Adrenergic alpha Blockers,Adrenergic alpha Receptor Blockaders,Agents, alpha-Adrenergic Blocking,Antagonists, alpha-Adrenergic,Blockaders, Adrenergic alpha-Receptor,Blockaders, alpha-Adrenergic Receptor,Blockers, alpha-Adrenergic,Blocking Agents, alpha-Adrenergic,Receptor Blockaders, alpha-Adrenergic,alpha Adrenergic Antagonists,alpha Adrenergic Blockers,alpha Adrenergic Blocking Agents,alpha Adrenergic Receptor Blockaders,alpha Blockers, Adrenergic,alpha-Antagonists, Adrenergic,alpha-Receptor Blockaders, Adrenergic