Module 3 Lecture 2 Flashcards
Describe the PDZ.
Ensures that NMDA and AMPA receptors are next to each other. PDZ are inside of PSD - 95. Scaffolds large ion channels. Synaptic strength decreased when PSD - 95 is KO, affects LTP.
How do chandelier cells work?
A subset of GABAergic neurons that synapse at the AIS. Axo - axonic. Can inhibit firing of postsynaptic cell (pyramidal neuron).
Describe temporal and spatial summation.
Temporal summation is when each signal is separated by time that will lead into an action potential.
Spatial summation requires two neurons creating synapses on one cell. The signal from each synaptic target arrive at the same time on the neuron. Separated by space.
What is the purpose of cell adhesion molecules?
CAM are on the cell surface. For example, Cadherin molecules are Ca2+ dependent. Plays a role of cell adhesion.
How does activity shape synapses?
Dendrites mature over time. Become wider and stubby. If you get more synapses overtime, the dendrite becomes stronger. Activity shapes synapse. The brain then becomes more refined through pruning.
How do receptors know where to go?
Nanoclusters. When the receptors are concentrated together, they are more stable. When they use this method, they found that the location of receptors is important.
The anchoring proteins (PSD 25, PDZ, scaffold proteins) find the location of where the NT will release and create a landing site for the glu- receptors. If you don’t have PSD 95, the receptors will spread and you won’t get Glu- binding.
What is the role of Neurexin and Neurligin?
Serves as a transynaptic bridge. hey are partners, one expressed by presynaptic, the other expressed post synaptic. They function as cell adhesion molecules, bridging the synaptic cleft.
How do we find the Ca2+ channels on presynaptic cell?
scaffold proteins connect Ca2+ channels to the synaptic vesicles. On the channels, there are proteins that can find neurexin ( a2 delta binds to neurexin).
Two major principles that determine receptor binding
Strength of the binding and concentration of the drug.
Name the kinds of ligands that bind to receptors.
Agonist - activates
Antagonist - inhibits
Allosteric - binds away from the active site to enhance or inhibit and agonist.
