Signal Generation & Propagation Flashcards
What is the excitability property of a neuron?
-the likelihood that a neuron will fire an action potential depending upon the strength of the input signal
What is Rheobase?
-the minimum current injected needed to reach threshold
High extracellular calcium will ______ excitability of neurons.
Decrease
Low extracellular calcium will _______ excitability of neurons.
Increase
What is neuromodulation?
- refers to mechanisms that dynamically change how information is being processed through the nervous system
- typically only used to refer to short term modulations
How is neuromodulation typically produced?
- by activating cellular enzyme systems that produce covalent modifications of channels and receptors
- viva Ca2+ & G-Proteins
What are the two main classes of plasticity?
- Excitability =changes in likelihood of firing APs in response to same stimuli
- synaptic =strength of connections between neurons
What are the mechanisms of short term excitability plasticity?
- Inactivation
- Ca2+ sensitive channel gating
What are the mechanisms of intermediate term excitability plasticity?
- Channel phosphorylation shifting gating parameters
- Redox sensitivity of channel gating
What are the mechanisms of long term excitability plasticity?
- Changes in auxiliary subunit composition
- changes in expression levels
- alternative splicing
Which receptor is normally blocked by Mg2+?
NMDA
Which ions passing through NMDA receptors at the synapse play an important role in regulating synaptic plasticity?
-Ca2+ ions
