Lightning-Nl
Bluelighter
- Joined
- Nov 11, 2012
- Messages
- 1,247
I'm having a problem clarifying this with resources on the internet. My understanding of neurons, nerves and neurotransmitters is; there are hundreds of different neurotransmitters. Each one is released by a corresponding neuron. However, these neurons can only release one neurotransmitter, but all neurotransmitters can bind to a neuron. Based on the exact function of that neuron, the binding of this neurotransmitter will open that corresponding ion channel, allowing the cell to either gain or inhibit an action-potential and if an action-potential can be obtained - the neuron will fire and that will send that message of excitation or inhibition down one of it's axons and release it's corresponding neurotransmitter on the other side of the synaptic cleft.
Again, based on the function of that neuron - neurotransmitters can "tell" two different neurons to do other things. For instance, ACh tells neurons in the Autonomic Nervous System (when they bind to Nicotinic receptors) to become excited. This is what causes heart rate to increase so dramatically when smoking a cigarette - because Nicotine is mimicking ACh at Nicotinic receptors which sends the message of excitation thus increasing your heart rate. However, ACh sends the message of inhibition in certain regions of the Cerebellum and in certain muscular tissues (however, this action is more Muscarinic mediated in the case of ACh, but that's beside the point) it will tell muscular tissue to become inhibited which will cause the tissue to relax and inhibit movement.
However, with recent research I've done, I feel that this view may be a little over simplistic. But what about the original principle that all axonal branches of a neuron release the same transmitter? It now appears to me that there are at least a few exceptions to this principle. Going back to motor neurons, which are important for voluntary muscle movements, have long been known to release acetylcholine onto both muscle cells in the body and neurons in the spinal cord. However, based on some recent studies that I read; it was proven that motor neurons also release a second transmitter - glutamate. But, they appear to release glutamate onto neurons in the spinal cord and not onto muscle cells - in other words, certain branches of a single neuron release glutamate, and others do not.
So my question is - does one neuron release one neurotransmitter? Or is this only true for specific axons of a neuron? or is this true only for certain neurons and sub-nervous systems? or was my original concept correct?
Again, based on the function of that neuron - neurotransmitters can "tell" two different neurons to do other things. For instance, ACh tells neurons in the Autonomic Nervous System (when they bind to Nicotinic receptors) to become excited. This is what causes heart rate to increase so dramatically when smoking a cigarette - because Nicotine is mimicking ACh at Nicotinic receptors which sends the message of excitation thus increasing your heart rate. However, ACh sends the message of inhibition in certain regions of the Cerebellum and in certain muscular tissues (however, this action is more Muscarinic mediated in the case of ACh, but that's beside the point) it will tell muscular tissue to become inhibited which will cause the tissue to relax and inhibit movement.
However, with recent research I've done, I feel that this view may be a little over simplistic. But what about the original principle that all axonal branches of a neuron release the same transmitter? It now appears to me that there are at least a few exceptions to this principle. Going back to motor neurons, which are important for voluntary muscle movements, have long been known to release acetylcholine onto both muscle cells in the body and neurons in the spinal cord. However, based on some recent studies that I read; it was proven that motor neurons also release a second transmitter - glutamate. But, they appear to release glutamate onto neurons in the spinal cord and not onto muscle cells - in other words, certain branches of a single neuron release glutamate, and others do not.
So my question is - does one neuron release one neurotransmitter? Or is this only true for specific axons of a neuron? or is this true only for certain neurons and sub-nervous systems? or was my original concept correct?
