Inhibitory Neurotransmitter Flashcards
What is the purpose of an inhibitory neurotransmitter?
It tries to stop an action potential from occurring in a muscle or nerve. (It can cancel out
action potentials.)
What does an inhibitory neurotransmitter do when it is released at a
synapse?
It causes a hyperpolarization to occur (in the muscle or nerve it is released onto).
A hyperpolarization is when the resting potential becomes MORE NEGATIVE. A
hyperpolarization is a small negative charge.
A hyperpolarization can cancel out a depolarization that might be present—because it is
negative charge, the opposite of a depolarization, which is a positive charge. This is how
a hyperpolarization can keep an action potential from occurring.
What specific ion channel is opened by an inhibitory neurotransmitter?
An inhibitory NT opens gated potassium channels. This lets potassium exit the cell,
creating a hyperpolarization.
This means an inhibitory NT’s receptor is actually a gated potassium channel.
What is an inhibitory neurotransmitter that is used in skeletal muscle?
Dopamine
How does Parkinson’s disease show the importance of inhibitory
neurotransmitters in our bodies?
With Parkinson’s disease, the brain produces less and less dopamine over time.
This means that dopamine no longer cancels out action potentials in skeletal muscle.
The result is that the body has uncontrolled muscle contractions (tremors).
What is an inhibitory neurotransmitter used solely within the CNS?
How is it useful medicinally?
GABA. It stops action potentials from being made in the brain. Anticonvulsants (seizure
medicines) for epilepsy stop seizures because they increase GABA release.
Seizures are caused by random action potentials that fire off in the brain.
Many neurotransmitters have BOTH _____ or ______ effects,
depending upon the receptor type they bind to in an organ.
excitatory, inhibitory
