Презентация PowerPoint

Яка роль нейромедіаторів. Associate Professor of the Department of Medical and Biological Chemistry, Medical Biology, General Genetics Tashkent Pediatric Medical Institute KARIMOVA SHAIRA FATKHULLAEVNA.

What are Neurotransmitters? Neurotransmitters are chemical messengers that transmit signals across a synapse from one neuron (nerve cell) to another "target" neuron, muscle cell, or gland cell. They play a crucial role in the functioning of the nervous system, influencing everything from muscle contractions to mood regulation..

The classification of neurotransmitters is based on their chemical structure, function, site of action and mechanism of action.

2.By Function: Excitatory Neurotransmitters: Function: These neurotransmitters stimulate the brain, promoting the generation of action potentials in neurons. Examples: Glutamate, Aspartate Inhibitory Neurotransmitters: Function: These neurotransmitters inhibit the brain by reducing the likelihood of action potentials in neurons, promoting relaxation and reducing anxiety. Examples: GABA (Gamma-Aminobutyric Acid), Glycine Modulatory Neurotransmitters: Function: These neurotransmitters do not directly excite or inhibit neurons but modulate the effects of other neurotransmitters. They play a role in regulating various functions like mood, arousal, and motivation. Examples: Dopamine, Serotonin, Norepinephrine (Noradrenaline), Acetylcholine.

3.By Site of Action: Central Neurotransmitters: Location: Act primarily within the central nervous system (CNS), which includes the brain and spinal cord. Examples: Glutamate: The main excitatory neurotransmitter in the CNS. GABA (Gamma-Aminobutyric Acid): The main inhibitory neurotransmitter in the CNS. Dopamine: Involved in reward, motivation, and motor control. Serotonin: Regulates mood, appetite, and sleep. Peripheral Neurotransmitters: Location: Act primarily in the peripheral nervous system (PNS), which includes all nerves outside the brain and spinal cord. Examples: Acetylcholine: Functions at neuromuscular junctions, enabling muscle contraction. Also found in autonomic ganglia. Norepinephrine: Functions in the sympathetic nervous system, influencing heart rate and blood pressure..

4.By Mechanism of Action: Ionotropic Neurotransmitters: Mechanism: These neurotransmitters bind to ionotropic receptors, which are ion channels. When the neurotransmitter binds to the receptor, it causes the ion channel to open or close, resulting in a rapid change in the neuron's membrane potential. Examples: Glutamate: Binds to NMDA and AMPA receptors, causing an influx of calcium and sodium ions. GABA (Gamma-Aminobutyric Acid): Binds to GABA_A receptors, causing an influx of chloride ions, leading to hyperpolarization. Acetylcholine: Binds to nicotinic acetylcholine receptors, causing an influx of sodium and calcium ions..

4.By Mechanism of Action: 2.Metabotropic Neurotransmitters: Mechanism: These neurotransmitters bind to metabotropic receptors, which are G-protein coupled receptors (GPCRs). Binding to these receptors activates G-proteins, which then trigger a series of intracellular signaling cascades. This leads to slower, but more prolonged changes in the neuron's activity. Examples: 1. Dopamine: Receptors: D1, D2, D3, D4, D5 (all are G-protein coupled receptors) Functions: Involved in reward, motivation, motor control, and regulation of mood. 2. Serotonin: Receptors: 5-HT1 to 5-HT7 (most are G-protein coupled receptors) Functions: Regulates mood, appetite, sleep, memory, and learning. 3. Norepinephrine (Noradrenaline): Receptors: Alpha and beta adrenergic receptors (all are G-protein coupled receptors) Functions: Involved in attention, arousal, and the "fight-or-flight" response. 4. Acetylcholine: Receptors: Muscarinic acetylcholine receptors (mAChRs, which are G-protein coupled receptors) Functions: Involved in cognitive functions, memory, and muscle contractions..

5. Glutamate: Receptors: Metabotropic glutamate receptors (mGluRs, which are G-protein coupled receptors) Functions: Plays a role in synaptic plasticity, learning, and memory. 6. GABA (Gamma-Aminobutyric Acid): Receptors: GABA_B receptors (which are G-protein coupled receptors) Functions: Functions as an inhibitory neurotransmitter, reducing neuronal excitability throughout the nervous system. 7. Histamine: Receptors: H1, H2, H3, H4 (all are G-protein coupled receptors) Functions: Involved in immune responses, regulation of gastric acid secretion, and neurotransmission in the brain..

Neurotransmitters. Major characteristics of neurotransmitters They are chemicals synthesized within the neuron. They are released when the cell is activated by an action potential They have an effect on a target cell (neuron or muscle cell). When the release of the neurotransmitter is blocked, an action potential will not result in activity in the postsynaptic neuron. One neuron can release one, two or more neurotransmitters..

Let's consider individual neurotransmitters.

Neurotransmitters. Amino acids The two main amino acids Glutamate, which has an excitatory effect, GABA (gamma-aminobutyric acid), which has an inhibitory effect. Two other amino acids that also serve as neurotransmitters Aspartate, which is excitatory Glycine, which is inhibitory..

Neurotransmitters. Glutamate The main excitatory amino acid neurotransmitter in the CNS. This neurotransmitter is used at approximately 15 to 20% of synapses in the CNS. There are four major glutamatergic receptors. Three are ionotropic (NMDA, AMPA, kainate) The fourth is the metabotropic glutamate receptor..

Acetylcholine: Important for signaling in the central nervous system and peripheral nervous system. Dopamine: Related to the regulation of movement, motivation, and pleasure. Serotonin: Affects mood, sleep, and appetite. Norepinephrine (norepinephrine) Functions: Participates in the regulation of wakefulness, stress and anxiety. It also plays a role in the fight-or-flight response. Location: In the brain and peripheral nervous system, especially in the sympathetic nervous system..

Adrenaline (epinephrine) Functions: Important for responding to stressful situations. Increases heart rate, widens the airways and increases blood flow to the muscles. Location: Secreted from the adrenal glands and affects many parts of the body. Histamine Functions: Involved in the regulation of sleep, appetite and allergic reactions. It also plays a role in the body's immune response. Location: In the central nervous system and in other tissues associated with the immune system. Endorphins Functions: Acts as natural painkillers and induces feelings of euphoria. They are often released during exercise. Location: In the central nervous system..

Acetylcholine Functions: It is involved in the transmission of nerve impulses in the central and peripheral nervous system. It is especially important for the functions of memory, learning and muscle activity. Location: Located in the synapses of nerve cells, where it transmits signals from neurons to muscles, which causes them to contract. Conditions: Acetylcholine deficiency is associated with diseases such as Alzheimer's disease. Dopamine Functions: It is responsible for movement control, motivation, pleasure and reward. Dopamine also affects mood and cognitive function. Location: Located in various areas of the brain, including an area known as the "reward system." Conditions: Dopamine deficiency is associated with Parkinson's disease, and excess dopamine is associated with schizophrenia and other mental disorders..

Oxytocin Functions: Although it is better known as a hormone, it also acts as a neurotransmitter in the brain. Oxytocin transmits signals between nerve cells, playing an important role in regulating social interactions, emotional responses, and bonding. Its dual role as a hormone and neurotransmitter makes it a particularly interesting object to study in neuroscience and psychology. Oxytocin is known as the "love hormone" or "cuddle hormone" because of its role in social attachment and trust formation. It also plays an important role in childbirth and lactation. Location: Produced in the hypothalamus and released into the blood through the pituitary gland. Diseases: Studies show that oxytocin levels can affect social interactions and mental health. Low oxytocin levels may be linked to autism and other social behavior disorders..

Conclusion: All of these neurotransmitters work in harmony to create a complex network of interactions that keeps our bodies balanced and functioning. They modulate each other, ensuring that processes such as attention, memory, mood, social interactions, and stress responses flow smoothly..