What is the neurotransmitter that is released into the synaptic cleft?

Answer 1

Vesicles containing the neurotransmitters are caused to fuse with the neuron's cell membrane, which thereby presents the neurotransmitters to the outside of the neuron, into the synapse.

As I'm sure you know a neurotransmitter is how two neurons communicate at a synapse. It can be one of many molecules, often nor-epinephrine/nor-adrenaline. Neurotransmitters are stored in structures called vesicles in a bulb at the end of the axon the presynaptic neuron. These vesicles are like balloons containing the neurotransmitters, what would be the rubber of the balloon is actually made of the same plasma membrane that surrounds the rest of the cell. When the Action Potential (AP) coming down the axon gets to the bulb it causes Ca ion channels to open. These channels are membrane bound proteins ant act as voltage gated channels in the same way the Sodium ion channels in the axon do. The opening of these channels allows calcium entry into the cells. There are another class of membrane bound proteins that are important here, the Docking proteins. Ca ions activate the docking proteins by binding to them. What these proteins do is effectively grab the vesicles, containing the neurotransmitter, and make the membrane merge with the cells membrane. This is exactly like the opposite of phagocytosis, the cell then secretes the neurotransmitter into the synaptic cleft.

The neurotransmitter must then & isreleased from the receptor site, in order to prevent continuing and constant over-stimulation of the post-synaptic neuron. It can be carried back to the presynaptic neuron for either repackaging into vesicles or broken down there by enzymes, or some neuropeptide neurotransmitters simply diffuse away into the surrounding medium, and one (acetylcholine) is broken down right in the synaptic cleft.

Answer 2

Electrical stimulation of the nerve cell, down the dendrite and to the synapse, once released it has to find a sympathetic receptor cite across the synapse for it to transmit, and so on and so on to elaborate the single cell activation into the multiple activation which then allows function.

Brain, thinking, muscle activation-whatever, or wherever the cells are

Answer 3

Norepinephine- which is released at synaptic nerve endings, responds to hypotension and physical stress.

Acetylcholine is released at SOME synapses in the spinal cord and at neuromuscular junctions; it influences muscle action.

Answer 4

When a threshold stimulus is presented to the neuron, it is depolarized, making it possible for the neurotransmitter to be released into the synaptic cleft.

Answer 5

acecylocholine

Answer 6

Calcium channel gate open