Abstract

Neurotransmitters play important roles in neurogenesis; in particular, acetylcholine and serotonin may regulate neurite elongation. Acetylcholine may also activate transcription factors such as early growth response protein 1 (EGR-1), which plays a role in neurite extension. N18TG2 neuroblastoma cells (which do not produce neurotransmitters and constitutively express muscarinic acetylcholine receptors) were transfected with constructs containing the cDNA for choline acetyltransferase, 5-hydroxytryptamine 1A (5-HT<sub>1A</sub>) and 5-HT<sub>2B</sub> serotonin receptors to study acetylcholine and serotonin interplay in neurite outgrowth. 5-HT<sub>1A</sub> receptor stimulation causes a decrease in EGR-1 levels and inhibition of neurite outgrowth; 5-HT<sub>2B</sub> stimulation, however, has no effect. Muscarinic cholinergic stimulation, on the other end, increases EGR-1 levels and fiber outgrowth. Inhibition of EGR-1 binding reduces fiber outgrowth activity. When both cholinergic and 5-HT<sub>1A</sub> receptors are stimulated, fiber outgrowth is restored; therefore, acetylcholine counterbalances the inhibitory effect of serotonin on neurite outgrowth. These results suggest that EGR-1 plays a role in the interplay of acetylcholine and serotonin in the regulation of neurite extension during development.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call