WAY-100135 dihydrochloride is a potent and selective antagonist of both presynaptic and postsynaptic 5-HT 1A receptors, exhibiting an IC 50 value of 34 nM specifically at the rat hippocampal 5-HT 1A receptor. This compound displays promising antipsychotic effects.

5-HT1A receptor:34 nM (IC50)

WAY100135, at concentrations ranging from 0.1 to 1 µM, counteracts the contractions induced by 5-carboxamidoiodotryptamine following electrical stimulation in the guinea-pig ileum, exhibiting a pA2 value of 7.2[1]. Furthermore, at a dose of 10 µM, WAY-100135 dihydrochloride inhibits the dampening effect of 8-OH-DPAT on both excitatory and inhibitory postsynaptic currents in MVM neurons[2].

WAY100135, administered at a dose of 2.5 mg/kg, results in a peak inhibitory effect of 30% on the firing activity of raphe neurons, while a 0.5 mg/kg intravenous (i.v.) dose counters the firing inhibition caused by 8-OH-DPAT in anesthetized rats. Additionally, WAY-100135 dihydrochloride at a concentration of 10 mM in a 1 μL volume for microinjection completely mitigates all behavioral deficits in rats induced by 5-HT.