Ion channels types

Several hundred species of Conus snails produce a wide array of small (12-30 AA) and mostly tightly disulfide bonded peptide ligands with high affinity for a diverse set of receptor and ion channel types. 

Two groups of acetylcholine receptors have been identified in humans the muscarinic (mAChR) and nicotinic (nAChR) receptors, named after their artificial activating ligands, muscarine and nicotine. These receptors function through entirely different mechanisms, either as a slow acting metabotropic G-protein-coupled receptor (mAChR) or fast acting ion-channel type receptor (nAChR). 

Postsynaptic nicotinic receptors in the peripheral nervous system are designated as (in autonomic ganglia) and N2 (at myoneural junctions). Nicotinic receptors are of the ion channel type. They are pentameric proteins that are composed of one, two, or more distinct subunits, each of which contains multiple membrane-spanning regions, and the individual subunits surround an internal channel (28). Nicotinic receptors are highly heterogeneous, and subcategorization has been difficult those in neuronal tissue are believed to... 

A family of presynaptic ion channel-type acetylcholine receptors in the brain modulates the release of acetylcholine, dopamine, and other neurotransmitters implicated in learning and memory processes (37). There is convincing evidence to implicate a deficit in nicotinic receptors in the symptomatology of Alzheimer s disease. Furthermore, the neurotoxin /3-amyloid attenuates nicotine-induced release of acetylcholine and dopamine (37). 

Avermectin Bia has been shown to stimulate chloride ion uptake into cockroach muscle ( 140 and block transmission at the arthropod neuromuscular junction by increasing GABA-mediated chloride ion permeability (15), (16). To extend our understanding of ion channel types present in the surface membrane of the synaptosome we examined the effects of ivermectin (22,23-dihydroavermectin B.) and some closely related milbemycins. Both ivermectin and the milbemycins examined, with the exception of milbemycin a9, were... 

Understanding the mechanisms underlying regulation of K" " channel activity by acute reduction in environmental O2 has been hampered by the fact that in 02-sensing tissues these channels often represent only one of a whole gamut of native, expressed K channel proteins, as well as other ion channel types. Furthermore, pharmacological and/or biophysical dissection of specific K" " channel types is not always possible. Clearly, to study in detail the precise mode of hypoxic K" " channel inhibition, it would be desirable to record activity from a pure... 

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