Acetylcholine receptors in dissociated nucleus basalis of Meynert neurons of the rat.

Electrical and pharmacological properties of acetylcholine (ACh)-induced currents in neurons dissociated from the nucleus basalis of Meynert (nBM) of immature (2-week-old) rats were investigated with the whole-cell mode of the patch-clamp technique. At a holding potential (VH) of -50 mV, ACh (10(-4)M) evoked a transient inward current mimicked by nicotine (InACh), followed by a sustained outward current mimicked by carbamylcholine (ImACh). The KD values were 1.2 x 10(-4) M for ImACh and 8.7 x 10(-7) M for ImACh. The reversal potential of ImACh was close to EK. The ImACh was determined to be elicited via the M2 muscarinic receptor, based on the differences in sensitivity to muscarinic antagonists such as pirenzepine and AF-DX-116.