Neurotransmission

Plasticity occurs during trauma and aging, trauma or surgery, and after prolonged exposure to drugs and diseases. Several prominent early studies on factors affecting the expression of cotransporters in sympathetic nerves have been made and the physiological role of neurogenic cytokines in the control of developing VIP expression in cholinergic sympathetic neurons is proposed It was done. Recent studies have shown that cholinergic differentiation in sympathetic neurons is a neurotrophic factor derived from three different protein families (neurotrophic cell derived neurotrophic factor, neurotrophic factor 3 and ciliary neurotrophic factor) Indicated. But nerve growth factor promotes noradrenergic differentiation. In another study, BDNF was claimed to convert sympathetic transmission to the heart from adrenergic stimulation to cholinergic inhibition; it also showed that BDNF is mediated by the P75 neurotrophic receptor. Histamine, galanin and GABA act as cotransporters in neurons of the nodular papillary nucleus (hypothalamus) with independent regulatory mechanisms. Changes in the chemical coding of mesenteric neurons in ulcerative colitis have been reported to be from cholinergic to more SP-positive simultaneous metastases. Evidence for the expression of the CGRP regulatory SP (NK1) receptor was proposed in a study using primary cultures of neonatal rat spinal cord neurons.

Although the density of SPRP - like immunoreactive fibers did not change, CGRP - like immunoreactivity was found to increase early in the older age than SP - like immunoreactivity in cerebrovascular nerves. NA and NPY also show different expression of cerebral vascular nerves during development. Direct evidence for a change in disease spreading rate comes from a study of hypertension in which the sputum component of sympathetic transmission is claimed to be enhanced to some extent as a major component of the sympathetic response . In many isolated vessels, contractions caused by cross-linked nerve stimulation, or contractions caused by vasoconstrictors including catecholamines and 5-HT are greater during endothelial removal or antagonism of endothelium-derived relaxing factors. Although some of this effect may include a post-engagement mechanism, evidence is provided that substances released from the endothelium can function functionally and affect neurotransmitter release from nerves. It may or may not contain endothelium-derived NO. ATP is also released from endothelial cells in response to physiological stimuli (such as hypoxia or shear stress), thus degrading the adiponectin to adenosine and diffusing through the vascular wall and then activating the P1 receptor by pre-binding the activity of peripheral blood vessels It can be adjusted. In contrast, in the microvasculature with smaller neuroendothelial cell separation, common mediators released from nerves act directly on endothelial cells, thereby affecting the release of endothelium-derived factors.

As mentioned above (Figure 3), information is transmitted in the brain through a process called neurotransmission. Neurotransmitters contain various chemical substances called "neurotransmitters". One such neurotransmitter is known as "dopamine". During normal communication, dopamine is released into the synapse by neurons (small gaps between neurons). Later dopamine binds to specific proteins on adjacent neurons called "dopamine receptors" (see figure) and signals the neurons.

Chemical neurotransmission occurs at a chemical synapse. In chemical neurotransmission, presynaptic neurons and postsynaptic neurons are separated by small gap-synaptic gaps. The synaptic cleft is filled with extracellular fluid (all cells immersed in the brain). Although very small, usually on the order of a few nanometers (one billionth of a meter), the synaptic gap creates physical barriers to transfer the electrical signal carried by one neuron to another neuron. Electrically, the synapse clearance is considered a "short circuit" in the circuit. The function of the neurotransmitter is to overcome this electrical short circuit. It acts like a chemical messenger that ties the action potential of one neuron to the synaptic potential of another neuron. How this happens is explained in the animation below.