What triggers neurotransmitters?
1 Answer
In response to a threshold action potential or graded electrical potential a neurotransmitter is released at the presynaptic terminal.
Explanation:
The axon is a single long tube that extends from the soma with multiple branching at end of it. The main function of the axon is to carry a message from the soma to the terminal buttons that release neurotransmitters into the synaptic cleft.
Calcium is a vital element in the process of neurotransmitter release. When calcium ion channels are blocked neurotransmitter release is inhibited. When the action potential reaches the nerve terminal, voltage dependent calcium ion channels open and calcium ions rush into neuron terminal due to a greater extra cellular concentration. Calcium ions bind with the membrane of the synaptic vesicles, which causes the vesicles to break and release the neurotransmitters into the synaptic cleft.
The neurotransmitters are stored in tiny membrane packets called synaptic vesicles which can be triggered to secrete by fusing with the presynaptic membrane at the transmitter release site.
