Role Of Î±7-Nicotinic Acetylcholine Receptors In Tetanic Stimulation-Induced Î³ Oscillations In Rat Hippocampal Slices
Hippocampal Î³ oscillations, as a form of neuronal network synchronization, are speculated to be associated with learning, memory and attention. Nicotinic acetylcholine receptor Î±7 subtypes (Î±7-nAChRs) are highly expressed in hippocampal neurons and play important roles in modulating neuronal function, synaptic plasticity, learning and memory. However, little is known about the role of Î±7-nAChRs in hippocampal Î³ oscillations. Here, we examined the effects of selective Î±7- and non-Î±7-nAChR antagonists on tetanic Î³ oscillations in rat hippocampal slices. We found that brief tetanic stimulation-induced Î³ oscillations (30-80 Hz) and pharmacological blockade of Î±7-nAChRs using the relatively selective Î±7-nAChR antagonists, methyllycaconitine (10 or 100 nM) or Î±-bungarotoxin (10 nM), significantly reduced the frequency spectrum power, the number of spikes, and burst duration of evoked Î³ oscillations. Neither mecamylamine nor dihydro-Î²-erythroidine, which are selective antagonists of non-Î±7-nAChRs, demonstrated significant effects on tetanic Î³ oscillations. Nicotine exposure promotes hippocampal Î³ oscillations in a methyllycaconitine-sensitive manner. It is concluded that Î±7-nAChRs in hippocampal slices play important roles in regulation of Î³ oscillations, thus potentially helping to explain roles of nAChRs in cognitive functions such as learning, memory and attention. Â© 2005 Elsevier Ltd. All rights reserved.
Digital Object Identifier (DOI)
Song, Chuanzhe; Murray, Teresa A.; Kimura, Ryoichi; Wakui, Makoto; Ellsworth, Kevin; Javedan, Sam P.; Marxer-Miller, Syndia; Lukas, Ronald J.; and Wu, Jie, "Role Of Î±7-Nicotinic Acetylcholine Receptors In Tetanic Stimulation-Induced Î³ Oscillations In Rat Hippocampal Slices" (2005). Neurobiology. 463.