Ligand-gated channel

Besides sodium channels, other ion channels such calcium- and potassium channels as well as certain ligand-gated channels are affected by local anaesthetics. However, this plays only a minor role for nerve block but may have more impact on adverse effects induced by systemical concentrations of these drags. 

The open channel has in most cases a selective permeability, allowing a restricted class of ions to flow,for example Na+, K+, Ca++ or Cl- and, accordingly, these channels are called Na+-channels, K+-channels, Ca -channels and Cr-channels. In contrast, cation-permeable channels with little selectivity reject all anions but discriminate little among small cations. Little is known about the structures and functions of these non-selective cation channels [1], and so far only one of them, the nicotinic acetylcholine receptor (nAChR, see Nicotinic Receptors), has been characterized in depth [2, 3]. The nAChR is a ligand-gated channel (see below) that does not select well among cations the channel is even permeable to choline, glycine ethylester and tris buffer cations. A number of other plasma... 

In addition to the pre-synaptic effects, CX3CL1 modulates the functional properties of ligand-gated channels at post-synaptic sites. In SK-N-SH cells, a human neuroblastoma cell line, CX3CL1 reduces the amplitude of NMDA-induced calcium transients (Deiva et al. 2004). In these cells, CX3CL1 application causes a PTX insensitive transient increase in the intracellular Ca " concentration dependent on... 

Nicotinic receptor subunits are part of a large superfamily of ligand-gated channels 202... 

Cyclic AMP can be viewed as subserving two major functions in the nervous system. First, cAMP mediates some short-term aspects of synaptic transmission some rapid actions of certain neurotransmitters on ion channels that do not involve ligand-gated channels are mediated through cAMP. 

Unwin, N. (1993) Neurotransmitter action opening of a ligand-gated channel. Neuron 10 Suppl., 31-41. 

Ca2+ enters cells via a number of plasma membrane channels which belong to three families (Figure 11.2) (i) voltage-gated channels (ii) ligand-gated channels and (iii) capacitative, or store-operated channels (SOCs). 

The other ligand-gated channel is commonly referred to as the ryanodine receptor, after the alkaloid ryanodine, which can induce opening or closing as a function of concentration. 

Many receptors for neurotransmitters function as ligand-gated channels for Na and/or Ca " ions (see p. 354). The ones that have been studied in the greatest detail are the nicotinic receptors for acetylcholine (see p. 352). These consist of five separate but structurally closely related subunits. Each forms four transmembrane helices, the second of which is involved in the central pore in each case. The type of monomer and its arrangement in the complex is not identical in all receptors of this type. In the neuromuscular junction (see p. 334), the arrangement aPya8 is found (1). 

Na K ATPase Vollaec Dependent Channel Ligand Gated Channel... 

The open state of the Ca channels of the cell membrane is controlled by different signals. We know of voltage-gated Ca channels that are opened by a depolarization or change in membrane potential. There are also Ca chaimels that are controlled by G-protein-mediated signal transmission pathways, and ligand-gated channels (see Chapter 16). It is also reported that InsPs can activate Ca " channels in the cell membrane. 

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