excitatory synapse

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excitatory synapse

A synapse which, on activation, increases the likelihood of an action potential on the post-synaptic neuron or increases the frequency of firing of the post-synaptic neuron.


the junction between the processes of two neurons or between a neuron and an effector organ, where neural impulses are transmitted by chemical means. The impulse causes the release of a neurotransmitter (e.g. acetylcholine or norepinephrine) from the presynaptic membrane of the axon terminal. The neurotransmitter molecules diffuse across the synaptic cleft, bind with specific receptors on the postsynaptic membrane, causing depolarization or hyperpolarization of the postsynaptic cell. See also neuron.

adrenergic synapse
the neurotransmitter is norepinephrine. See also adrenergic (1).
axoaxonic synapse
axodendritic synapse
axodendrosomatic synapse
one between the axon of one neuron and the dendrites and body of another.
axosomatic synapse
cholinergic synapse
the neurotransmitter is acetylcholine. See also cholinergic.
dendrodendritic synapse
one from a dendrite of one cell to a dendrite of another.
excitatory synapse
a synapse in which the transmission of impulses is electrical not chemical. Found only in fish and invertebrates.
inhibitory synapse
hyperpolarizing electrical current is used to raise the threshold for the stimulation of a discharge of an impulse from the particular kind of nerve cell, found only in fish.