exam 1 vocab Flashcards
spike timing dependent plasticity
-the order and precise temporal interval between presynaptic and post synaptic spikes determine the sign and magnitude of LTP and LTD
EPSP- pre and 3 AP post
- presynaptic inputs led / were synchronous with postsynaptic spikes= LTP
- LTD= presynaptic input followed postsynaptic spike
time between EPSP and 1st AP is 10ms = strong LTP
time is 50ms= no LTP
LTD- 50 ms post before pre= strong LTD
90ms post before pre= no LTDsyonsos
tetanus
a high frequency train of electrical stimuli used to induce LTP using 100hz for 1s or low frequency train of 1hz for 100s to induce LTD
EPSP
“excitatory postsynaptic potential”
- postsynaptic potential that makes the neuron more likely to fire an action potential.
- temporary DP of postsynaptic membrane potential that is caused by the flow of (+) charged ions into the postsynaptic cell that is a result of opening ligand-gated ion channels
- EPSPs is a graded response that reflects the nature and magnitude of neurotransmitters released at the synapse at any given point in time. EPSPs differ from action potentials in that they are sub-threshold responses that decay very rapidly in time and space.” -McGill University
mEPSP
“miniature excitatory postsyanptic potential”
- measure of the spontaneous vesicle release from the presynaptic terminal without any stimulation present.
- the release is probabilistic.
EPSC
In the “voltage clamp” mode, the voltage is kept constant, so it is possible to record the current passing through the open ion channels, called “postsynaptic current”
structural LTP
Spine enlargement due to presynaptic and postsynaptic excitability.
co-immunoprecipitation using antibodies
- used to ID protein-protein interactions by using target protein specific AB to indirectly capture proteins that are bound to a specific target protein
- protein complexes can be analyzed to ID new binding partners, binding affinities, the kinetics of binding and function of the target protein.
- different than immunoprecipitation because the experiment targets to ID the interacting proteins and not the antigen
Field Potential
The average of multiple EPSPs by multiple electrodes.
APV (AP5)
NMDAR antagonist (competitively binds to NMDAR binding sites.)
CNQX
Competitive AMPAR antagonist
TTX
Inhibits firing of action potentials by binding to voltage-gated Na Channels
Hebb Rule
Cells that Fire together Wire Together
NMDA
Specific agonist at the NMDAR receptor that mimics the action of glutamate.
AMPAR
ionotropic transmembrane receptor for glutamate that mediates fast synaptic transmission.
NMDAR
ionotropic glutamate receptor, predominant molecular device for controlling synaptic plasticity and memory function.
phosphatases
-involved in LTD and synaptic weakening because when there are lower levels of ca2+ present because have a higher affinity which then causes dephosphorylation of substrates
FRET
- distance-dependent interaction between the electronic excited states of two dye molecules in which excitation is transferred from a donor molecule to an acceptor molecule without emission of a photon.
- also, used to investigate molecular interactions.
- The transfer of energy leads to a reduction in the donor’s fluorescence intensity and excited state lifetime, and an increase in the acceptor’s emission intensity.
EXAMPLE:
http://www.biotek.com/assets/tech_resources/159/fig-3.gif
“Protein-protein interactions between proteins labeled A and B bring Blue fluorescent protein and GFPs in close enough proximity to allow for FRET to occur. In this example, excitation of blue fluorescent protein results in the emission of fluorescence by GFP.
PSD-95
A protein almost exclusively located in the post synaptic density of neurons, and is involved in anchoring synaptic proteins. It plays an important role in synaptic plasticity and the stabilization of synaptic changes during long-term potentiation.
PSD-95
A protein almost exclusively located in the post synaptic density of neurons, and is involved in anchoring synaptic proteins. It plays an important role in synaptic plasticity and the stabilization of synaptic changes during long-term potentiation.
involved in clustering with AMPAR immobilizing them in the neurite
phospho- specific anitbody
antibodies that bind to protein and detect any phosphorylation-induced conformational changes
primary and secondary antibodies
primary AB binds to target protein and a secondary AB (against primary) binds to primary AB and emits fluorescence
changes in intensity indicate changes in activity
protein kinase (camk2, pka, pkc)
kinase enzyme that modifies other proteins by chemically adding phosphate groups to them (phosphorylation). Phosphorylation usually results in a functional change of the target protein (substrate) by changing enzyme activity, cellular location, or association with other proteins.
By adding phosphate groups to substrate proteins, they direct the activity, localization and overall function of many proteins, and serve to orchestrate the activity of almost all cellular processes.
tyrosine kinase (BDNF)
enzyme that can transfer a phosphate group from ATP to a protein in a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases are a subclass of protein kinase. all tyrosine kinases regulate target protein function through transfer of phosphate from ATP to the hydroxyl group of a target protein tyrosine.
Most receptor tyrosine kinases are single-pass, transmembrane proteins that bind extracellular polypeptide ligands (i.e. growth factors) and cytoplasmic effector and adaptor proteins to regulate biological processes. Ligand binding promotes receptor dimerization and autophosphorylation of receptor tyrosine residues. The resultant conformational change stabilizes the active kinase, and subsequent phosphorylation events form binding sites for downstream adaptor, scaffold, and effector proteins.
Glutamate Uncaging
absorption of two photons for conversion to active glutamate, resulting in a substantial improvement in spatial resolution over conventional caged glutamate. Used to map the distribution of glutamate receptors
Synaptic Cleft
a gap between the pre- and postsynaptic cells that is about 20 nm wide. The small volume of the cleft allows neurotransmitter concentration to be raised and lowered rapidly
G Protein
proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to the inside.
Their activity is regulated by factors that control their ability to bind to and hydrolyze guanosine triphosphate (GTP) to guanosine diphosphate (GDP). When they bind GTP, they are ‘on’, and, when they bind GDP, they are ‘off’. G proteins belong to the larger group of enzymes called GTPases. These enzymes can now make a new messenger molecule, called cyclic AMP.
Postsynaptic Density
protein dense specialization attached to the postsynaptic membrane. The PSD has been proposed to concentrate and organize neurotransmitter receptors in the synaptic cleft. The PSD also serves as a signaling apparatus. During synaptic plasticity, the total size of the PSD increases along with an increase in synaptic size and strength after inducing long-term potentiation at single synapses
phosphodeficient mutation (T286A)
unable to be phosphorylated
Point mutation- alanine
phosphomimetic mutation (T286D)
point mutation- aspartate
mimics phosphorylation
Autophosphorylation
It is generally defined as the phosphorylation of the kinase by itself. Occurs by the addition of a phosphate group to serine, threonine or tyrosine residues within protein kinases, normally to regulate the catalytic activity.
CA1
region of the hippocampus
comprised of pyramidal cells
little recurrent connections
involved in LTP
BDNF
A protein that acts on certain neurons, that helps to support the survival of existing neurons, and encourage the growth and differentiation of new neurons and synapses
Subunit Exchange
The exchange of a phosphorylated subunit for an unphosphorylated subunit within a haloenzyme which then becomes phosphorylated by autophosphorylation.
Dominant Negative
A mutation that is introduced into the genome through transfection. For example if it is a kinase, it is pronounced “kinase dead” if it is physically present but inactive.
Adhesion Molecule
Cell adhesion molecules (CAMs) are proteins located on the cell surface[1] involved in binding with other cells or with the extracellular matrix (ECM) in the process called cell adhesion. In essence, cell adhesion molecules help cells stick to each other and to their surroundings.
