Cholinergic currents in Xenopus oocytes transplanted with human brain membranes

Cholinergic human brain currents were recorded in Xenopus laevis oocytes transplanted with human cerebral membranes from two different zones, the frontal cortex and the hippocampus. The recorded currents were supported by the nicotinic or the muscarinic acetylcholine receptor. We tested the effects of a number of several nicotinic agonists acetylcholine, nicotine and 1,1-dimethyl-4-phenyl-piperazinium iodide (DMPP), and the nicotinic receptor antagonists a-bungarotoxin and d-tubocurarine on the transplanted oocytes. We detected four kinds of nicotinic current kinetics. The differences in the amplitude and in the total electric charge of the currents elicited by various agonists at a range of holding potentials were not significant, except in the case of DMPP at a holding potential of-90 mV. Our results indicate that α4β2, α3β4 and α7 are the main nicotinic receptors in human brain. Key words: Human cortex.—Neuronal nicotinic currents.—Xenopus oocytes.— Membrane transplant.—Alzheimer.—Brain bank. RESUMEN Corrientes colinérgicas en oocitos de Xenopus trasplantados con membranas de cerebro humano Corrientes colinérgicas de cerebro humano fueron registradas en oocitos de Xenopus laevis trasplantados con membranas de cerebro humano procedentes d