presynaptic neuron

presynaptic neuron

a neuron from the axon terminal of which an electrical impulse is transmitted across a synaptic cleft to the cell body or one or more dendrites of a postsynaptic neuron by the release of a chemical neurotransmitter.
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The [alpha]-function delivers the neurotransmitter from the presynaptic neuron to the postsynaptic neuron gradually.
As the connection increases when a presynaptic neuron fires, [W.sub.j--k,x] denotes this increase in the weight from neuron j to neuron k either excitatory or inhibitory.
If you don't have a reservoir of neurotransmitters, the drugs soon may become ineffective or tachyphylactic and cause a greater excretion of neurotransmitters via monoamine oxidase and catechol-O-methyltransferase, creating a deficiency of neurotransmitters in the presynaptic neuron. Of interest, he notes that the width of the synapse is 1 millionth of a centimeter and that the average neurotransmitter binding time to a postsynaptic receptor last 1 thousanth of a second.
For the sake of simplicity, the design has omitted both the axon and axon-terminals as subelements, as the design allows the cell body of the presynaptic neuron directly assigns a stimulus to the dendrites of postsynaptic neurons.
The model we have proposed is fundamentally probabilistic because not all of the neurotransmitters leaving presynaptic neuron arrive the adjacent postsynaptic membrane.
(1, 3) NO travels backward across a chemical synapse to bind to the axon terminal (NO receptor/sGC) of a presynaptic neuron for regulation of ANT this process is called as the retrograde neurotransmission (RNT).
When a voltage change, the so-called action potential, reaches the synaptic terminal in the presynaptic neuron, calcium flows through voltage-gated calcium channels into the presynaptic neuron.
(1993), "cellular research has shown that the introduction of dopamine into synapses immediately after a postsynaptic neuron has been activated by a presynaptic neuron produces long-lasting changes in synaptic efficacies.
Increased calcium within the presynaptic neuron can lead to increased glutamate release into the synapse and increased postsynaptic neuronal calcium can increase the NMDA signal transduction.
The neuron-muscle chemical connection, as well as the chemical connection from neuron B110 onto neuron B19, was studied by injection of depolarizing current into presynaptic neuron B110.
(3) Excitotoxicity: Routinely, certain amino acids, like glutamate, are released from a presynaptic neuron and flow to a nearby postsynaptic neuron, promulgating the nerve impulse.
Group II and Group III mG1uRs also are present on the axon terminal of the presynaptic neuron. When they are activated by some of the glutamate released by the presynaptic neuron, they alter the presynaptic neuron's activity so that further glutamate release is prevented (Schoepp 2001); this is called a negative feedback mechanism.