Neurotransmitter systems of the brain

As mediators sinaptich e tion transmission is now known a large number of chemical substances, the list of which has not yet been completed. Neurotransmitters are divided into several groups: acetylcholine, serotonin, catecholamine (dopamine, n of p-epinephrine, adrenalin), amino acids, neuropeptides ergic purine derivatives. All neurotransmitters, except amino acids, are synthesized from precursors circulating in the blood. The distribution of neurons, and with various mediators, in the nervous system is uneven. H and Rushen produce certain mediators in certain brain structures associated with the pathogenesis of a number of neuropsychiatric diseases. So, from about holding dopamine in Parkinson reduced and increased at schizo-Fresnes reducing norepinephrine and serotonin is typical for d e compressively states and their increase – for mania.

One of the most common mediators is atsetilh of Lin, who is the main neurotransmitter that transmits information r mation in the brain and in peripheral nerve endings of the ox of the con. Brain neurons excited by acetylcholine p e CEPT on ry, play a large role in the manifestation of some mental functions. It was found that the death of these neurons leads to senile weak on umiyu (Alzheimer’s disease).

Dopaminergic neurons in mammals are the primarily e -governmental in the midbrain, as well as in the hypothalamic region. Dopamine of mammalian brain stems circuit well understood. Three main chains are known, they all consist of a single neuron chain. The bodies of the neurons are located in the brain stem and send axons to other areas of the brain. One chain is very simple. The body of the neuron is located in the hypothalamus and sends a short axon to the pituitary gland. This path is part of the hypothalamic-pituitary system and controls the system of the endocrine glands. W of Paradise dopamine system is also well understood. It is a black substance, many of whose cells contain dopamine. The axons of these neurons are the projection and banded in striatum. This system contains approximately 3/4 dopamine in the brain. It is crucial in regulating Tonichi e Sgiach movements. A dopamine deficiency in this system leads to Parkinson’s disease. It is known that this disease is not death occurs first tron substantia nigra. The introduction of L-DOPA (dopamine precursor) relieves some symptoms of the disease in patients. Third dofam and The nerve system is involved in the manifestation of schizophrenia and some other mental illnesses. The functions of this system have not been studied enough yet, although the paths themselves are well known. The bodies of neurons lie in the midbrain next to the substantia nigra. They project axons into the overlying structures of the brain, cortex and limbic system. According to the dopamine hypothesis of schizophrenia, the third dopaminergic system is overactive in this disease. These views arose after the discovery of substances that relieve some of the symptoms of the disease. For example and action, chlorpromazine and haloperidol have different chemical nature, but they equally inhibit the activity of the dopaminergic system of the brain and the manifestation of certain symptoms of schizophrenia. In patients with schizophrenia, for a year receiving these drugs, there are motor n and destructions called tardive dyskinesia (repetitive bizarre two and facial muscles, including the musculature of the mouth, which the patient cannot control).

Serotonergic neurons are widely distributed in the central nervous system, they innervate vast areas of the brain, including the cerebral cortex, hippocampus, pale ball, amygdala, region r and potalamus. Interest in serotonin was attracted due to the problem of sleep. With the destruction of the seam nuclei, animals suffered from insomnia. Substances that deplete serotonin storage in the brain have a similar effect. At most s sokaya detected concentration of serotonin in the epiphysis ( pineal gland ). Serot o nin in the epiphysis turns into melatonin, which is involved in skin pigmentation and also affects the activity of the female gonads in many animals. And from the last few years, they show the important role of melatonin in pr about cessa slowing the aging of the body. Melatonin’s ability to function as a neurotransmitter has also been found. The content of both serotonin and melatonin in the pineal gland is controlled by the light cycle – the dark about that through sympathetic nervous system. In addition, serotonin is called a mood neurotransmitter. It is believed that the decrease in the level of the connected e Nia plays a role in the development of depression.

Another group of CNS mediators consists of amino acids, such as glutamic acid, glutamine, aspartic acid, gamma-aminobutyric acid (GABA), and others. Glutamate in the nervous tissue is formed mainly from glucose. In mammals, glutamate is most abundant in the terminal brain and cerebellum, where its concentration is about 2 times higher than in the brain stem and spinal cord. In the spinal cord glutamate is distributed unevenly: it is located in the posterior horns more late Mr. tration than in front. Glutamate is one of the propagation n GOVERNMENTAL neurotransmitters in the central nervous system. Of GABA inhibitory neurotransmitters it is most prevalent in the central nervous system, other known inhibitory neurotransmitter yavl I is glycine. Glycinergic neurons are located mainly in the spinal cord and medulla. A large group of neurotransmitters amounted to lyayut neuropeptides. Opioid peptides (enkephalins, endorphins, etc.) are the most important representatives of this group, they take part in the regulation mechanisms of other neurotransmitters, and also mediate the development processes of various diseases caused by the onset of dependence (alcoholism, drug addiction, etc.).

In most cases, the role of neurotransmitters in the neural transmission of the signal lies in their ability to bind to receptors postsinaptich e tion membrane that leads to opening of the ion channel, or to Activate of vaniyu intracellular reactions. The emergence of immunochemical methods has allowed us to show that several groups of mediators can coexist in one synapse, and not one, as previously assumed. For example, in the statement of Dr. Mr. synaptic terminals at the same time may be sinaptich e skie vesicles containing acetylcholine and norepinephrine, which are fairly easy to identify on the electronic images. In addition to classical mediators, there may be one or none in the synaptic terminal . how many neuropeptides. The number of substances contained in the synapse, m of Jet be up to 5 – 6. Furthermore, mediator synapse m specificity of Jet vary ontogeny. For example, the sympathetic ganglia neurons that innervate the sweat glands in mammals originally noradrene p tech, but in adult animals become holinergichnymi.

local_offerevent_note April 12, 2019

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