The type 3 serotonin (5-HT(3)) receptor is a ligand-gated ion channel. In concentration-clamp experiments, we investigated the effects of the uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonists memantine, amantadine and MRZ 2/579 on 5-HT receptors stabley expressed in HEK-293 cells and on native 5-HT(3) receptors in the N1E-115 cell line. All agents antagonized serotonin (10 microM)-...

Serotonin is an ancient monoamine neurotransmitter, biochemically derived from tryptophan. It is most abundant in the gastrointestinal tract, but is also present throughout the rest of the body of animals and can even be found in plants and fungi. Serotonin is especially famous for its contributions to feelings of well-being and happiness. More specifically it is involved in learning and memory...

Serotonin (5-HT) modulates both neural and immune responses in vertebrates, but its role in insect immunity remains uncertain. We report that hemocytes in the caterpillar, Pieris rapae are able to synthesize 5-HT following activation by lipopolysaccharide. The inhibition of a serotonin-generating enzyme with either pharmacological blockade or RNAi knock-down impaired hemocyte phagocytosis. Bioc...

The superficial cells of the entorhinal cortex (EC), main input to the hippocampus, receive a serotonergic input from the raphe nuclei and express 5-hydroxytryptamine creatine sulfate complex (5-HT) receptors at high density. With the use of intracellular recordings, we investigated the effects of serotonin on synaptic inhibition of layer II and III neurons of the EC. Serotonin reduced both pol...