Exam I Flashcards
Confirmation of hypotheses in science require what two related things?
What major feature of a neuron is critical for its function?
Confirmation of hypotheses in science require advancement of techniques and improving our resolution of analysis.
Neurons are highly polarized, a feature that is critical for their function.
Na channels accumulated where? Action potentials initiate where?
_____ has increased the pace of neuroscientific discovery and is probably the most common technique used in research today.
What is GFP?
Na channels accumulated at axon initial segment and action potentials initiate at AIS.
Fluorescence-based imagining has increased the pace of neuroscientific discovery and is probably the most common technique used in research today.
GFP is a non-toxic protein fluorophore.
There is evidence for a ‘filter’ at what part of the axon? What does this filter do and therefore play a role in?
There is evidence for a ‘filter’ at the axon initial segment of neurons that restricts diffusion of certain proteins potentially playing a role in neuronal polarization.
What things determine the membrane potential of a neuron?
The resting membrane potential of a neuron is determined primarily by ____, and therefore is close to what?
Ion distribution and permeability determine the membrane potential of a neuron.
The resting membrane potential of a neuron is determined primarily by potassium channels, and therefore is close to the Ve(K+) or EK, the potassium equilibrium potential.
Different _____ are involved in controlling subthreshold and supra threshold depolarization.
___ channels are expressed at the Calyx of Held terminals, which have an unusual ___ and determine the _____.
Different ion channels are involved in controlling subthreshold and supra threshold depolarization.
KCNQ5 channels are expressed at the Calyx of Held terminals which has an unusual hyperpolarized activation voltage and determine the resting membrane potential.
Different _____ are uniquely suited to studying aspects of neuronal excitability and function.
Ion channels are highly diverse and exhibit unique properties which have largely been elucidated using ____ and ____.
Imaging methods have big advantage in imaging what?
Different neuronal recording techniques are uniquely suited to studying aspects of neuronal excitability and function.
Ion channels are highly diverse and exhibit unique properties which have largely been elucidated using current recordings in neurons and expression systems.
Imaging methods has big advantage in imaing multiple compartments and small structure (axon terminals, spines).
What three methods have been used to stimulate neurons? Briefly describe them.
Electrical stimulation, uncaging, and optogenetics have been used to stimulate neurons.
Compare/contrast current recordings vs. imaging methods vs. electricalstmulaion. e.g. what kinds of techniques for each and what are they best for studying?
Current recordings (patch-clamp, voltage-clamp, whole-cell,...) - best for studying ion channels. Imaging methods (genetically-encoded indication, two-proton fluorescence..) - best for studying compartments and small structures e.g. axon terminals, Ca2+, spines).
Electrical stimulation, uncaging (photoactivation), optogenetics - best for neuron stimulation.
Chemical synapse & electrical synapse are two main what?
Briefly explain an electrical synapse.
Chemical synapses have what morphology, and found where? In regards to direction, how can chemical synapses propagate a signal?
Chemical synapse & electrical synapse are two main modalities of synaptic transmission.
Electrical synapse is a symmetrical electrically conductive link between two neighboring neurons that is formed at a narrow gap between the pre- and postsynaptic neurons known as a gap junction.
Chemical synapses are asymmetric morphology with distinct features found in the pre- and postsynaptic parts. Chemical synapses can only prop info from pre- to post-synaptic neuron.
Ribbon synapses occur where? (2)
Ribbon synapses occur where synaptic exocytosis is evoked by graded depolarization and where signaling requires a high rate of sustained release.
The process of synapse development can be roughly divided into what4 steps?
____ proteins are critical players throughout synapse development and mediate what 4 things?
The process of synapse development 4 steps: 1) Initial contact, 2) Induction/ Differentiation, 3) Maturation and 4) Maintenance/ Exchange.
Trans-synaptic proteins are critical players throughout synapse development mediating: initiation, specificity, adhesion but also mature function.
_____ composition changes during maturation.
Due to chloride cotransporters changing, what 2 things occur during development?
Postsynaptic receptor composition changes during maturing.
Due to chloride cotransporters changing, post-synaptic chloride concentration decreases during development, and GABA/Glycine activation switch from depolarizing/excitatory to hyperpolarizing/inhibitory.
Trans-synaptic proteins are critical players throughout _____.
Due to _____, post-synaptic chloride concentration decreases during development, and GABA/Glycine activation switch from ____ to _____.
Trans-synaptic proteins are critical players throughout synapse development mediating: initiation, specificity, adhesion but also mature function.
Due to chloride cotransporters changing, post-synaptic chloride concentration decreases during development, and GABA/Glycine activation switch from depolarizing/excitatory to hyperpolarizing/ inhibitory.
Briefly describe classic neurotransmitters (what are they, where are they synthesized/released? what do they do?…)
There are many different types of neurotransmitters with different release mechanisms. How many different kinds of neurotransmitters can a neuron can release?
Classic neurotransmitters are endogenous chemicals that synthesized and released by the presynaptic neuron and causes action on the postsynaptic neuron through receptors.
There are many different types of neurotransmitters with different release mechanisms. A neuron can release more than one neurotransmitter.
The Neuron Doctrine was pioneered by whom and states what?
The Neuron Doctrine was pioneered by Ramon Y Cajal and states that the brain is made up of independently functioning cellular units called Neurons.
What 2 neurotransmitter gradients 2 transport mechanisms exist and what can they modulate?
2 transport mechanisms are Na+/H+ exchange or cation/H+ exchange.
2 neurotransmitter gradients: extracellular to cytoplasmic and then to vesicular. Extracellular-intracellular concentration gradient for synaptic vesicles (intracellular NT concentration is ~ 1-10mM lower (level?)). Can modulate synaptic transmission
At what concentration level is the cytoplasmic neurotransmitter and to what does this contribute?
Cytoplasmic sodium modulates what?
Cytoplasmic neurotransmitter concentration regulates what? (And at what location?)
Cytoplasmic neurotransmitter is at 1-10 mM level and contributes to stronger synaptic transmission.
Cytoplasmic sodium modulates vesicular glutamate transport.
Cytoplasmic neurotransmitter concentration regulates vesicular cycling at a GABA synapse.
What controls the pre-synaptic action potential waveform? What does the pre-synaptic action potential waveform determine?
Exogenous Ca 2+ buffers are used to mimic what and study what?
Different ion channels control the pre-synaptic action potential waveform, which determines calcium channel activation and Ca 2+ influx.
Exogenous Ca2+ buffers are used to mimic endogenous Ca2+ and used to study the coupling/distance between Ca 2+ channel and Ca2+ sensor.
