a chemically gated channel
A neurotransmitter is a chemical or peptide in synapses, usually between neurons, a neuron and muscle or a neuron and other organ. The neurotransmitter transmits information to and from and within the brain. When a neurotransmitter is released from the presynaptic cell in response to depolarization of the cell by an action potential, it diffuses across the synaptic cleft and binds a receptor or ligand-gated ion channel on the postsynaptic cell. Binding on the postsynaptic cell alters the resting potential of the postsynaptic cell in either an inhibitory or excitatory manner, making the cell less susceptible or more susceptible (respectively) to an action potential. Examples include, but are not limited to, acetylcholine, GABA, noradrenaline, serotonin and dopamine.
neurotransmitter neurotransmitter neurotransmitter
Your question isn't very clear.... Presynaptic knob is the neurone before the synapse. Postsynaptic knob is the neurone after the synapse. Calcium ions diffuse into the presynaptic knob down their concentration gradient when an impulse arrives at the presynaptic knob. This causes the vesicles to move towards the presynaptic membrane and fuse with it. This releases the neurotransmitter (e.g. Ach). The Ach diffuses down their concentration gradient in the synaptic cleft then binds with receptors on the post synaptic membrane. This binding causes the Na+ ion channels to open, and the influx of Na+ ions causes depolarisation, and a new action potential in the postsynaptic knob. Then the acetate and choline diffuses back into the presynaptic membrane and is recombined using ATP.
Intracellular
... a receptor protein.
binds to specific receptors on postsynaptic cell membrane
A neurotransmitter is a chemical or peptide in synapses, usually between neurons, a neuron and muscle or a neuron and other organ. The neurotransmitter transmits information to and from and within the brain. When a neurotransmitter is released from the presynaptic cell in response to depolarization of the cell by an action potential, it diffuses across the synaptic cleft and binds a receptor or ligand-gated ion channel on the postsynaptic cell. Binding on the postsynaptic cell alters the resting potential of the postsynaptic cell in either an inhibitory or excitatory manner, making the cell less susceptible or more susceptible (respectively) to an action potential. Examples include, but are not limited to, acetylcholine, GABA, noradrenaline, serotonin and dopamine.
The action potential reaches the pre synaptic area, which opens a voltage sensitive Calcium ion gate, allowing calcium ions to move in via diffusion along an electrochemical gradient. The period of refraction (repolarisation) closes this gate. The increased conc. of Calcium ions pushes vesicles with neurotransmitter to the presynaptic membrane, where they fuse and exocytosis causes the neurotransmitter to be released across the synaptic cleft. The NT binds to a receptor which opens Na+ channels on the postsynaptic membrane, allowing depolarisation due to Na+ diffusion which continues the action potential across the other neurone. The neurotransmitters are broken down by enzymes or are reabsorbed by endocytosis into the presynaptic cleft, using energy from ATP.
neurotransmitter neurotransmitter neurotransmitter
Your question isn't very clear.... Presynaptic knob is the neurone before the synapse. Postsynaptic knob is the neurone after the synapse. Calcium ions diffuse into the presynaptic knob down their concentration gradient when an impulse arrives at the presynaptic knob. This causes the vesicles to move towards the presynaptic membrane and fuse with it. This releases the neurotransmitter (e.g. Ach). The Ach diffuses down their concentration gradient in the synaptic cleft then binds with receptors on the post synaptic membrane. This binding causes the Na+ ion channels to open, and the influx of Na+ ions causes depolarisation, and a new action potential in the postsynaptic knob. Then the acetate and choline diffuses back into the presynaptic membrane and is recombined using ATP.
The impulse itself does not actually cross the gap, which is called a synapse by the way, instead it stimulates the realease of a neurotransmitter from vesicles. When the neurotransmitter reaches the other side of the synapse it binds proteins on the opposing membrane and in doing so stimulates the membrane to continue the action potential on the mect cell.
what are the characteristics of action potentials
1. 1. Synthesized (made)2. 2. Stored/ packaged in synaptic vesicles3. 3. Transported down to the presynaptic end of the neuron4. Released into the synapse5. 5. Binds to receptors of postsynaptic neuron6. 6. Comes loose from receptor7. 7. Inactivateda. Destructionb. Reuptake- the major way to inactivate a neurotransmitter;SSRI -Selective serotonin reuptake inhibitors
Most neurons have a chemical synapse, which is to say that a substance called a neurotransmitter is released from the first neuron (called pre-synaptic) to the next neuron called (post-synaptic). How is the release triggered? When an action potential reaches the terminus (end of the axon) there are specialized calcium channels that are opened (voltage-gated). The calcium bind so the inner membrane and triggers the release of small membrane bound vesicles which spill out their contents of neurotransmitter into the synaptic cleft. The neurotransmitter binds to specific receptors on the post-synaptic membrane and that causes the action potential to propagate on (or for the neurotransmitter to cause an action like a muscle contraction).
a key fitting in the lock of a door
protein binds to a particle and uses energy to move through the cell membrane
Intracellular