NEURO TRANSMITTERS Neuro transmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. They packed into synaptic vesicles clustered beneath the membrane in the axon terminal on the pre synaptic side of synapse. They are released into and diffused across the synaptic Clift.
Neuro Transmitter
Life Cycle of a Neurotransmitter
1) Synthesis of the transmitter
2) Packaging and storage in Synaptic vesicles
3) If necessary, transport from the site of synthesis to the site of release from the nerve terminal
4) Release in response to an action potential
5) Binding to postsynaptic receptor proteins
6) Termination of action by diffusion, destruction, or reuptake into cells.
Neurotransmitters can be divided into two groups. They are “Classical ‘small molecule neurotransmitters and the larger neuropeptide neurotransmitters. The biogenic amines (dopamine, noradrenaline, serotonin and histamine) are also part of small molecule neurotransmitters. HOW NEUROTRANSMITTERS WORK
Synapse is a microscopic gap that receives the Neurotransmissions. It splits the transmitting neuron from the cell getting the chemical signal. The cell that generates the signal is called the presynaptic cell. He cell that receiving the signal is called postsynaptic cell. The neurotransmitters merge chemically with highly precise protein molecules. When this process is set in surface of membrane of the postsynaptic cell results the voltage, or electrical force of the cell which is either increased or decreased. Normally the neuron voltage is about-70 mill volts. The electrically charged molecules move back and forth across the neuron membrane. This flow of ions (electrically charged molecules) makes the neuron’s voltage toward zero. The electrically charged ions move back and forth across the cell membranes. This moment makes the neurons voltage rise toward zero. This generates nerve impulse that released the Neurotransmitter into the next synapse.
The neurotransmitters in the synapses releases chemical signals. The presynaptic neuron clears the synapse of neurotransmitter molecules. Acetylcholine is broken down by the enzyme acetylcholinesterase into choline and acetate. Neurotransmitters like dopamine, serotonin and GABA are removed by a physical process called reuptake. A protein in the presynaptic membrane mops the neurotransmitters to reenter the presynaptic neuron where repackaged for reuse.
Neurotransmitters are recognized to be caught up in a number of disorders.
Chemical Classification of Neurotransmitters:
A. Acetylcholine
B. Biogenic Amines
1. Catecholamines: Dopamine, norepinephrine (NE), and
2. epinephrine
3. Indolamines
4. Serotonin and histamine
5-Hydroxytryptamine or 5-HT)
C. Amino Acids
1. GABA—Gamma ()-amino butyric acid
2. Glycine
3. Aspartate
4. Glutamate
D. Neuropeptide
1. Substance P
2. Endorphins and Enkephalins
3.Somatostatin, gastrin, cholecystokinin, oxytocin, vasopressin,
4.Leutinizing hormone releasing hormone (LHRH) E. Purines 1.Adenosine 2. ATP F. Gases and Lipids
Nitric Oxide (NO)
Carbonmonooxide (CO)
Cannabinoids
Dr. Kesiraju Ramprasad
Educational Psychologist
