Related Experiment Video
Updated: Jun 12, 2026

Examining Monosynaptic Connections in Drosophila Using Tetrodotoxin Resistant Sodium Channels
Published on: February 14, 2018
6,7-Dihydroxy-2-dimethylaminotetralin (TL-99) stimulates postjunctional D-1 and D-2 dopamine receptors
J W Kebabian1, K Miyazaki, C W Grewe
1Biochemical Neuropharmacology Section, Experimental Therapeutics Branch, NINCDS, NIH, Bethesda, MD 20205, U.S.A.
Abstract:
6,7-Dihydroxy-2-dimethylaminotetralin (TL-99) mimicks the ability of dopamine either to enhance adenylate cyclase activity in homogenates of goldfish retina or to inhibit adenylate cyclase activity in homogenates of the intermediate lobe (IL) of the rat pituitary gland previously treated with cholera toxin. Both the dopamine stimulated adenylate cyclase activity in the fish retina and the dopamine inhibited adenylate cyclase activity in the rat IL are associated with cells postjunctional to the dopaminergic neurons innervating these tissues. Therefore, the present data do not support the contention that TL-99 is a selective presynaptic dopamine receptor agonist.
Related Concept Videos
Drugs Affecting Neurotransmitter Synthesis
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
Drugs Affecting GI Tract Motility: Dopamine Receptor Antagonists
Opioid Receptors: Overview
Direct-Acting Cholinergic Agonists: Pharmacological Actions
Adrenergic Neurons: Neurotransmission
Synthesis: Catecholamine synthesis requires tyrosine, which is taken...

