Chapter 8 - Synaptic Transmission & Neural Integration Flashcards
electrical signals transmitted through gap junctions
electrical synapses
release of neurotransmitters that activate signal transduction mechanisms
chemical synapses
Electrical signal is transferred to adjacent cell by ions flowing through _____.
gap junctions
narrow space between presynaptic and postsynaptic neurons
synaptic cleft
How wide is a synaptic cleft?
30-50 nm
Where are neurotransmitters synthesized?
in the cytosol of the axon terminal
EPSP
excitatory postsynaptic potential
IPSP
inhibitory postsynaptic potential
the summation of input to a neuron that determines whether the neuron will fire an action potential
neural integration
two or more postsynaptic potentials fired in rapid succession at the same synapse
temporal summation
two or more postsynaptic potentials from different synapses fired at approximately the same time
spatial summation
most abundant neurotransmitter in the PNS
acetylcholine
ACh
acetylcholine
AChE
acetylcholinesterase
enzyme that degrades acetylcholine (ACh)
acetylcholinesterase (AChE)
Acetylcholine is catalyzed by _____ and breaks down into _____ and _____.
acetylcholinesterase (AChE); acetate; choline
What happens to the choline after acetylcholine is degraded?
it is taken back into the presynaptic cell and used to synthesize more acetylcholine
What are the two ACh receptors?
nicotinic cholinergic and muscarinic cholinergic receptors
How many binding sites for ACh are on nicotinic cholinergic receptors?
2
Which catecholamines are primarily released by neurons in the CNS?
dopamine and norepinephrine
Which catecholamine is better knows as being released by the adrenal medulla as a hormone?
epinephrine
receptors that bind epinephrine and norepinephrine
adrenergic receptors
receptors that bind dopamine
dopaminergic receptors
Which enzymes degrade catecholamines?
MAO and COMT
most abundant neurotransmitter in the CNS
amino acid neurotransmitters
_____ is the most commonly released neurotransmitter at excitatory synapses in the CNS.
Glutamate
_____ is the most commonly released neurotransmitter at inhibitory synapses in the CNS.
GABA
GABA
gamma-aminobuyric acid
Action potentials cause _____ channels to open during depolarization.
calcium
After an action potential, calcium flows down the electrochemical gradient and increases the cytosolic calcium in the _____.
axon terminal
CAT
choline acetyl transferase
_____ cholinergic receptors have two binding sites for acetylcholine.
Nicotinic
_____ cholinergic receptors operate through the action of a G protein.
Muscarinic
