11-4. Types of Synapses Flashcards
What are the types of neurotransmitters?
excitatory (go signals) and inhibitory (stop signals)
What happens when an excitatory neurotransmitter is released?
causes sodium channels to open > Na+ rushes in, making the inside less negative
What is an example of an excitatory neurotransmitter?
acetylcholine
The release of ACh from one synaptic knob is ___ to generate a nerve impulse
not enough, but neuron is now easier to excite
EPSP
excitatory postsynaptic potential - neuron is partially depolarized (less negative inside), bringing it closer to threshhold
threshold
the critical level of membrane potential at which a neuron generates an action potential
spatial summation
many synaptic knobs release neurotransmitters at the same time
temporal summation
one synaptic knob releases neurotrasmitter repeatedly
What is the result of spatial or temporal summation?
enough sodium gates may open to generate an action potential
What happens to ACh when the presynaptic neuron stops firing?
ACh in the cleft must be removed to prevent continuous stimulation of the postsynaptic neuron - destroyed by acetylcholinesterase
inhibitory synapse
stop signals - harder for neuron to generate a nerve impulse
What is an example of an inhibitory neurotransmitter?
GABA, glycine
What happens when an inhibitory neurotransmitter binds to the postsynaptic membrane?
Cl- channels open > Cl- flows in
K+ channels open > more K+ flows out
An inhibitory neurotransmitters makes the charge on the inside of the neuron ___, or ____.
even more negative than normal resting potential; hyperpolarized
IPSP
Inhibitory Postsynaptic Potential - when the postsynaptic neuron becomes even more negative inside, it is less likely to “fire” when stimulated
