Ligand gated means controlled by the or signal molecule. If the door is closed, certain are blocked from entering the cell. When the or signal molecule is attached, the door is open for certain to enter the cell. These types of receptors are important in the .

ligand; ions; ligand; ions; nervous system

Explanation:

Ligand-gated ion channels are transmembrane protein complexes that open when they bind to their corresponding ligands (e.g., neurotransmitters). This type of receptor is known to modulate the synaptic transmission between neuron cells or neuron and muscle cells. In the nervous system, ligand-gated ion channels located at sites of synaptic contact determine the ion flow in response to neurotransmitter binding. Some examples of ligand-gated ion channels include gamma-aminobutyric acid A (GABA-A) and nicotinic cholinergic receptors.

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