neurotransmitter

Examples of neurotransmitter in the following topics:

• Synaptic Transmission

  • The binding of a neurotransmitter to its receptor is reversible.
  • The effects of the neurotransmitter generally lasts few milliseconds before being terminated.
  • The neurotransmitter termination can occur in three ways.
  • Third, diffusion of the neurotransmitter as it moves away from the synapse.
  • Communication at chemical synapses requires release of neurotransmitters.

• Excitation–Contraction Coupling

  • Because neuron axons do not directly contact the motor-end plate, communication occurs between nerves and muscles through neurotransmitters.
  • The receptors are sodium channels that open to allow the passage of Na+ into the cell when they receive neurotransmitter signal.
  • Acetylcholine (ACh) is a neurotransmitter released by motor neurons that binds to receptors in the motor end plate.
  • As a neurotransmitter binds, these ion channels open, and Na+ ions cross the membrane into the muscle cell.
  • Explain the process of excitation-contraction coupling and the role of neurotransmitters

• Epinephrine and Norepinephrine

  • As a hormone and neurotransmitter, epinephrine acts on nearly all body tissues.
  • It is the hormone and neurotransmitter most responsible for vigilant concentration in contrast to its most-chemically-similar hormone, dopamine, which is most responsible for cognitive alertness.
  • One of the most important functions of norepinephrine is its role as the neurotransmitter released from the sympathetic neurons to affect the heart.
  • It is also a neurotransmitter in the central nervous system and sympathetic nervous system, where it is released from noradrenergic neurons in the locus coeruleus.

• Forms of Signaling

  • When these impulses reach the end of the axon, the signal continues on to a dendrite of the next cell by the release of chemical ligands called neurotransmitters by the presynaptic cell (the cell emitting the signal).
  • The neurotransmitters are transported across the very small distances between nerve cells, which are called chemical synapses .
  • The distance between the presynaptic cell and the postsynaptic cell—called the synaptic gap—is very small and allows for rapid diffusion of the neurotransmitter.
  • Enzymes in the synapatic cleft degrade some types of neurotransmitters to terminate the signal.

• Nerve Impulse Transmission within a Neuron: Action Potential

  • A neuron can receive input from other neurons via a chemical called a neurotransmitter.
  • When neurotransmitter molecules bind to receptors located on a neuron's dendrites, voltage-gated ion channels open.
  • For an action potential to communicate information to another neuron, it must travel along the axon and reach the axon terminals where it can initiate neurotransmitter release .

• Steroids

  • They can either activate or tone down receptors that communicate messages from neurotransmitters.

• Connecting Proteins to Glucose Metabolism

  • Most of the time, the amino acids are recycled into the synthesis of new proteins or are used as precursors in the synthesis of other important biological molecules, such as hormones, nucleotides, or neurotransmitters.

• Exocytosis

  • Some examples of cells releasing molecules via exocytosis include the secretion of proteins of the extracellular matrix and secretion of neurotransmitters into the synaptic cleft by synaptic vesicles.

• Neurodevelopmental Disorders: Mental Illnesses

  • For example, monoamine oxidase inhibitors (MAO inhibitors) block the enzyme that degrades many neurotransmitters (including dopamine, serotonin, norepinephrine), resulting in increased neurotransmitter in the synaptic cleft.

• Regulatory Proteins

  • During stimulation of the muscle cell, the motor neuron releases the neurotransmitter acetylcholine, which then binds to a post-synaptic nicotinic acetylcholine receptor.