LSD has high efficacy relative to serotonin in enhancing the cationic current Ih: Intracellular studies in rat facial motoneurons
Synapse February 1, 1993 Jennifer C. Garratt, Meenakshi Alreja, George K. Aghajanian 46 citations
LSD and serotonin (5-HT) both increase the electrical excitability of rat facial motoneurons, but through different mechanisms. While serotonin produces a reversible depolarization of about 5 mV by decreasing resting potassium conductance, LSD causes only a slight depolarization of 1-2 mV. Despite this, LSD strongly enhances the hyperpolarization-activated cation current I_h, more so than serotonin. LSD also attenuates the depolarizing effect of serotonin. The effects of LSD are blocked by the antagonists spiperone and ritanserin, indicating involvement of 5-HT2/5-HT1c receptors. These findings suggest LSD has high efficacy for enhancing I_h current but low efficacy for decreasing potassium conductance.