Role of alpha7-nicotinic acetylcholine receptors in tetanic stimulation-induced gamma oscillations in rat hippocampal slices
| Autor: | Ryoichi Kimura, Syndia Marxer-Miller, Makoto Wakui, Jie Wu, Chuanzhe Song, Sam P. Javedan, Kevin Ellsworth, Teresa A. Murray, Ronald J. Lukas |
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| Rok vydání: | 2004 |
| Předmět: |
Nicotine
Time Factors alpha7 Nicotinic Acetylcholine Receptor Aconitine Nicotinic Antagonists Hippocampal formation In Vitro Techniques Receptors Nicotinic Bicuculline Hippocampus GABA Antagonists Cellular and Molecular Neuroscience chemistry.chemical_compound Biological Clocks Mecamylamine medicine Biological neural network Animals Nicotinic Agonists Rats Wistar Pharmacology Methyllycaconitine Dose-Response Relationship Drug Chemistry Spectrum Analysis Dose-Response Relationship Radiation Bungarotoxins Electric Stimulation Rats Electrophysiology Nicotinic acetylcholine receptor nervous system Animals Newborn Synaptic plasticity Tetanic stimulation Neuroscience medicine.drug |
| Zdroj: | Neuropharmacology. 48(6) |
| ISSN: | 0028-3908 |
| Popis: | Hippocampal gamma oscillations, as a form of neuronal network synchronization, are speculated to be associated with learning, memory and attention. Nicotinic acetylcholine receptor alpha7 subtypes (alpha7-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 alpha7-nAChRs in hippocampal gamma oscillations. Here, we examined the effects of selective alpha7- and non-alpha7-nAChR antagonists on tetanic gamma oscillations in rat hippocampal slices. We found that brief tetanic stimulation-induced gamma oscillations (30-80 Hz) and pharmacological blockade of alpha7-nAChRs using the relatively selective alpha7-nAChR antagonists, methyllycaconitine (10 or 100 nM) or alpha-bungarotoxin (10 nM), significantly reduced the frequency spectrum power, the number of spikes, and burst duration of evoked gamma oscillations. Neither mecamylamine nor dihydro-beta-erythroidine, which are selective antagonists of non-alpha7-nAChRs, demonstrated significant effects on tetanic gamma oscillations. Nicotine exposure promotes hippocampal gamma oscillations in a methyllycaconitine-sensitive manner. It is concluded that alpha7-nAChRs in hippocampal slices play important roles in regulation of gamma oscillations, thus potentially helping to explain roles of nAChRs in cognitive functions such as learning, memory and attention. |
| Databáze: | OpenAIRE |
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