Modulation of the reaction of hippocampal neurons to sensory stimuli by cholinergic substances.

摘要: The influences of increasing endogenous acetylcholine (eserine) and its blockade (scopolamine) on the effects sensory stimuli were analyzed through extracellular recording activity individual hippocampal neurons awake rabbits. An increase in level acetylcholine, accompanied by appearance stable theta rhythm, leads to a substantial decrease reactivity neurons, suppression, attenuation, inversion majority inhibitory reactions proportion activational including on-responses specific type. At same time, limited group is intensified extended against background eserine. Scopolamine, which blocks does not change or intensifies some reactions, on-responses. Tonic are shortened; however, their gradual extinction disappears. described preserved hippocampus presence basal undercutting septum eliminates ascending brainstem pathways. These data make it possible draw conclusion that, under normal conditions, new (significant) stimulus elicits an initial stoppage (reset) with coordinated triggering rhythm passage this signals along cortical input phase relationship it. period modulation switched signal fosters limitation subsequent, interfering signals. septohippocampal may thus support mechanism selective attention, as necessary precondition for memory.