Synaptic Communication Part 2 Flashcards
Where is Acetylcholine found?
At the neuromuscular junction
What are the three main neurotranmitters and their locations?
1) Glutamate is the main excitatory transmitter in the central nervous system.
2) GABA is the main inhibitory neurotransmitter in the adult vertebrate brain.
3)Glycine is the main inhibitory neurotransmitter in the spinal cord and brainstem
Excitatory vs. Inhibitory
E: Making a target neuron more likely to fire an action potential
I: making a target neuron less likely to fire an action potential.
Example of how acetylcholine is excitatory and inhibitory
- Excitatory at the neuromuscular junction in skeletal muscle, causing the muscle to contract.
- Inhibitory in the heart, where it slows heart rate.
List three ionotropic glutamate receptors that are glutamate-gated cation channels and always produce excitatory postsynaptic responses.
1) AMPA
2) NMDA
3) Kainate
Glial cells
Produces glutamine from glutamate by the action of glutamine synthetase
VLGUT Transporters
Package glutamate synthesized in the presynaptic cytoplasm into synaptic vesicles
What happens at hyperpolarization and depolarization at inotropic glutamate receptors?
- At hyperpolarized potentials, Mg2+ resides within the channel pore and blocks it (left).
-Depolarization of the membrane potential pushes Mg2+ out of the pore, so that current can flow through the NMDA receptor
What type of receptors do GABA/glycines have? And cause the flow of what?
IONOTROPIC; and cause the flow of chloride to inhibit postsynaptic cells.
What is GABA synthesized from?
Synthesized from glutamate by the enzyme glutamic acid decarboxylase, which requires pyridoxal phosphate.
What amino acid acts as a precursor to glycine?
Serine
What happens when high-affinity transporters terminate the actions of neurotransmitters (GABA and Glycine)?
Return GABA or glycine to the synaptic terminals for reuse, with both transmitters being loaded into synaptic vesicles via the vesicular inhibitory amino acid transporter (VIAAT).
What happens to the activity of a neuron when GABA binds to it?
It silences the activity of a neuron
What happens when the pre-synaptic neuron is stimulated?
Gaba is released and is sensed by the receptor and the membrane potential flat lies, generating an inhibitory response
Immature neurons have a (HIGHER / LOWER) concentration of intracellular chloride, giving it a (DEPOLARIZING / HYPERPOLARIZING) effect.
higher, depolarizing (Since intracellular [Cl-] is high, Cl- will flow down its concentration gradient to outside of the cell where it makes the intracellular potential more positive and thus excitatory)
