Activation of dopamine D1-like receptors excites LTS interneurons of the striatum.
Dopamine (DA) has a crucial role in the modulation of striatal neuron activity. Along with projection cells, striatal interneurons receive dense dopaminergic innervation from midbrain neurons, thus, also suggesting that these intrinsic cells represent a synaptic target for DA action in the striatum. In the present study, we investigated the effects of DA on low-threshold spike (LTS) interneurons of the rat striatum, by means of in vitro whole-cell patch-clamp electrophysiological recordings. Dopamine depolarized LTS cells, a pharmacological effect prevented by D1- but not D2-like DA receptor antagonists. The membrane depolarization produced by DA was sufficient to trigger action potential discharge in the recorded cells and was insensitive to tetrodotoxin and glutamate receptor antagonists. In addition, this pharmacological effect was mimicked by D1- but not D2-like DA receptor agonists, implying the selective involvement of D1-like receptors in this action.
Centonze
Diego
D
Clinica Neurologica, Dipartimento di Neuroscienze, Università Tor Vergata, Via di Tor Vergata, 135, 00133 Rome, Italy.
Bracci
Enrico
E
Pisani
Antonio
A
Gubellini
Paolo
P
Bernardi
Giorgio
G
Calabresi
Paolo
P
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D001552:Benzazepines / Q000494:pharmacology; D048429:Cell Size / Q000187:drug effects / Q000502:physiology; D004298:Dopamine / Q000378:metabolism* / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D004558:Electric Stimulation; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D007395:Interneurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D017072:Neostriatum / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009924:Organ Culture Techniques; D051381:Rats; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000378:metabolism*; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013469:Sulpiride / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology
D001552:Benzazepines; D018492:Dopamine Antagonists; D018691:Excitatory Amino Acid Antagonists; D017447:Receptors, Dopamine D1; D026941:Sodium Channel Blockers; D013779:Tetrodotoxin; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D013469:Sulpiride; D004298:Dopamine