3.2 Chemical Events At The Synapse Flashcards
T.R. Elliott
A young British scientist, reported in 1905 that the hormone adrenaline closely mimics the effects of the sympathetic nervous system
Otto Loewi
A German physiologist, concluded that nerves send messages by releasing chemicals by using fluid from the heart of a frog and transferring it to another frog’s heart
Neurotransmitters
The chemicals that are released by one neuron at the synapse and that affect another
Amino acids
Acids containing an amine group (NH2)
Peptides
Chains of amino acids
Polypeptide
A long chain of amino acids
Protein
A still longer chain of amino acids
Monoamines
Nonacidic neurotransmitters containing an amine group, formed by a metabolic change of certain amino acids
An Amine group
(NH2)
Purines
A category of chemicals including adenosine and several of its derivatives
Nitric oxide
NO; A gas released by many small local neurons; it dilates the blood vessels to increase blood flow to the most active areas of the brain
Catecholamines
Epinephrine, norepinephrine and dopamine; contain a catechol group and an amine group
Vesicles
Tiny nearly spherical packets; where the presynaptic terminal stores high concentrations of neurotransmitter molecules
Exocytosis
The process of excreting the neurotransmitter through its membrane and into the synaptic cleft between the presynaptic and postsynaptic neurons
Dale’s principle
The incorrect generalization that each neuron released just one neurotransmitter
ionotropic effects
The neurotransmitter attaches to a receptor on the membrane of the postsynaptic neuron, almost immediately opening the gate for some type of ion; Rapid, but short-lived
Glutamate
The most abundant excitatory transmitter in the vertebrate brain
GABA
Inhibitory
Nicotinic synapses
They can be stimulated by the drug nicotine
Ionotropic synapses
Useful for conveying information about visual and auditory stimulation, muscle movements, and other rapidly changing events
Metabotropic effects
These effects take place by initiating a sequence of metabolic reactions that are slower and longer lasting than ionotropic effects
G-protein
A protein coupled to guanosine triphosphate, an energy-storing molecule
Second messenger
Carries a message to areas within the cell
Neuromodulator
An intermediate between a neurotransmitter a hormone; they affect all those nearby cells that have receptors for them
Acetylcholineterase
The enzyme that breaks down acetylcholine into two segments acetate and choline, after it has already activated a receptor
Reuptake
The process of the presynaptic neuron taking up most of these neurotransmitter molecules intact and reusing them; occurs through special membrane proteins called transporters
Transporters
Special membrane proteins that allow neurotransmitter molecules to be reuptaken
The enzymes that convert catecholamine transmitters into inactive chemicals
Catechol-o-methyl-transferase (COMT) and monoamine oxidase (MAO)
Sympathetic nervous system
A set of nerves that control the internal organs
