CSB332H1 Lecture Notes - Lecture 12: Inhibitory Postsynaptic Potential, G Protein–Coupled Receptor, Sk Channel
14 Mar 2014
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Document Summary
These three conditions reflect hyperactivation of different regions of the brain. Hyperactivation results in dramatic increase in the release of neurotransmitters. There could be uncontrollable release of neurotransmitters in the synaptic cleft. But neurons and brains have built-in mechanisms under normal physiological conditions to control uncontrollable release of neurotransmitters in the synaptic cleft. Neurotransmitter is released into the synaptic cleft. Autoreceptors meaning receptors for the self (e. g. , self-receptors). Autoreceptors can be located on the presynaptic axon or somatic dendritic sites of the neuron (e. g. , cell bodies, dendrites). After activation and depolarization, neurons have built-in mechanisms to regulate further neurotransmitter release. One mechanism is located on the postsynaptic cell. When neurotransmitters activate postsynaptic receptors, further postsynaptic activity is prevented by the activation of calcium- activated potassium channels: the cholinergic receptor that is activated by acetylcholine. The increased levels of ca2+ concentration in the cell activate the calcium-activated potassium channel: the calcium-activated potassium channel is permeable to k+.
