Neurotransmitters
Posted: Wednesday, August 4th, 2021 | Updated: Wednesday, August 4th, 2021
Posted: Wednesday, August 4th, 2021 | Updated: Wednesday, August 4th, 2021
Neurotransmitters Overview
Neurotransmitters are chemicals released by the presynaptic neuron and received by the postsynaptic neuron. The perpetuation of the nerve impulse is known as synaptic transmission. The synapse is the junction between two neurons or a neuron and a cell. The gap between the two neurons or a neuron and a cell is called the synaptic cleft. Neurotransmitters can be excitatory, inhibitory, or both
Excitatory Neurotransmitters
These neurotransmitters have a stimulating effect on postsynaptic membranes. They typically cause an influx of sodium into the cell so that the postsynaptic membrane moves closer to the threshold in order to depolarize. When the cell becomes more positively charged, it gets closer to the threshold
Inhibitory Neurotransmitters
These neurotransmitters typically hyperpolarize the postsynaptic membrane making the inside of the cell more negatively charged. They tend to open the chloride or potassium channels to complete this process. As a result, the cell gets further away from the threshold
Acetylcholine
Depending on the location, acetylcholine can be an excitatory or inhibitory neurotransmitter. It acts as an excitatory neuron at the junction between somatic motor neurons and muscles stimulating the muscles to contract. It acts as an inhibitory neuron where the nerves synapse with the heart causing it to beat slower
Norepinephrine, Epinephrine, and Dopamine (Catecholamines)
Norepinephrine and epinephrine play a role in the fight or flight mechanisms of the sympathetic nervous system. Dopamine tends to be involved with autonomic functions and muscle control
Gamma-aminobutyric Acid (GABA) and Glycine
These are inhibitory neurotransmitters. GABA is primarily found in the brain while glycine is found in the spinal cord
Neurotransmitters are chemicals released by the presynaptic neuron and received by the postsynaptic neuron. The perpetuation of the nerve impulse is known as synaptic transmission. The synapse is the junction between two neurons or a neuron and a cell. The gap between the two neurons or a neuron and a cell is called the synaptic cleft. Neurotransmitters can be excitatory, inhibitory, or both
Excitatory Neurotransmitters
These neurotransmitters have a stimulating effect on postsynaptic membranes. They typically cause an influx of sodium into the cell so that the postsynaptic membrane moves closer to the threshold in order to depolarize. When the cell becomes more positively charged, it gets closer to the threshold
Inhibitory Neurotransmitters
These neurotransmitters typically hyperpolarize the postsynaptic membrane making the inside of the cell more negatively charged. They tend to open the chloride or potassium channels to complete this process. As a result, the cell gets further away from the threshold
Acetylcholine
Depending on the location, acetylcholine can be an excitatory or inhibitory neurotransmitter. It acts as an excitatory neuron at the junction between somatic motor neurons and muscles stimulating the muscles to contract. It acts as an inhibitory neuron where the nerves synapse with the heart causing it to beat slower
Norepinephrine, Epinephrine, and Dopamine (Catecholamines)
Norepinephrine and epinephrine play a role in the fight or flight mechanisms of the sympathetic nervous system. Dopamine tends to be involved with autonomic functions and muscle control
Gamma-aminobutyric Acid (GABA) and Glycine
These are inhibitory neurotransmitters. GABA is primarily found in the brain while glycine is found in the spinal cord
Sources:
Colville, Thomas, and Joanna M. Bassert. Clinical Anatomy and Physiology for Veterinary Technicians. 2nd ed. Mosby Elsevier, 2008.
Colville, Thomas, and Joanna M. Bassert. Clinical Anatomy and Physiology for Veterinary Technicians. 2nd ed. Mosby Elsevier, 2008.