Neuroscience BSCI 353 Exam Questions Well Answered Latest Update 2025-2026
Voltage clamp vs patch clamp vs recording - Answers voltage clamp - measure current
patch clamp - measure current in pA
recording - measure membrane potential
What effects ion current through channel - Answers conductance and voltage drive
How does voltage clamp work and how do you read the graph - Answers Set potential of
membrane, changes in potential are corrected by a current that is read.
Negative current means depol (influx of postiive ions), postiive current means hyperpol (eflux of
positive ions)
Nernst equation - Answers 58/zlog(out/in)
Passive vs Active signaling - Answers Passive - change over short distance, signal leak out
Active - action potential, travel all the way down, at nodes of ranvier (when channels are open)
Hodgkin and Huxley 3 experiments and what they showed - Answers 1. clamp held at different
potentials - increase and decrease in inward current of NA - approaching equilibrium potential of
Na
2. Na+ removal - early inward current becomes outward, add Na back, restored
3. TTX and TEA blockers (Na and K) - TTX no inward current, TEA no outward current
All voltage clamp
Patch clamp experiment for Na and K channels - Answers Na - outside out, K blocker, small
inward current observed, Na channels make up bigger inward current
, K - Inside out, use Na blocker, outward current observed, K channel make up bigger outward
current
Structure of K channel - Answers selectivity filter - small, only dehydrated K come in
ATPase characteristics - Answers need both Na/K for transport (remove K, decrease Na
transport); need extracellular K (need K on outside to move inward to establish gradient)
need ATP in cytoplasm
Na channel characteristic - Answers transient inward flow due to inactivation
Xenopus oocyte used for - Answers insertion of channels to observe different Vg channels
Staining methods - Answers - Golgi - black, whole neuron
- Nissl - cell body, all bodies
- in situ - cell body, differential staining
- Ab labling - target protein
- GFP - see all cells, green
- fluorescent - one cell, fluorophore
- fMRI
Reticular vs neural - Answers reticular - connected everything
neural - spaces, discrete
Chemical vs electrical synapses - Answers electrical - bidirectional, fast, connected, gap junction
(connexin)
chemical - unidirectional, common, slower
Otto Loewi experiment - Answers 1. stimulate heart with vagus nerve, slow down
2. heart 1 and 2 connected by solution - stimulate heart 1, heart 2 slow down after delay
Conclusion: soluble transmision
Voltage clamp vs patch clamp vs recording - Answers voltage clamp - measure current
patch clamp - measure current in pA
recording - measure membrane potential
What effects ion current through channel - Answers conductance and voltage drive
How does voltage clamp work and how do you read the graph - Answers Set potential of
membrane, changes in potential are corrected by a current that is read.
Negative current means depol (influx of postiive ions), postiive current means hyperpol (eflux of
positive ions)
Nernst equation - Answers 58/zlog(out/in)
Passive vs Active signaling - Answers Passive - change over short distance, signal leak out
Active - action potential, travel all the way down, at nodes of ranvier (when channels are open)
Hodgkin and Huxley 3 experiments and what they showed - Answers 1. clamp held at different
potentials - increase and decrease in inward current of NA - approaching equilibrium potential of
Na
2. Na+ removal - early inward current becomes outward, add Na back, restored
3. TTX and TEA blockers (Na and K) - TTX no inward current, TEA no outward current
All voltage clamp
Patch clamp experiment for Na and K channels - Answers Na - outside out, K blocker, small
inward current observed, Na channels make up bigger inward current
, K - Inside out, use Na blocker, outward current observed, K channel make up bigger outward
current
Structure of K channel - Answers selectivity filter - small, only dehydrated K come in
ATPase characteristics - Answers need both Na/K for transport (remove K, decrease Na
transport); need extracellular K (need K on outside to move inward to establish gradient)
need ATP in cytoplasm
Na channel characteristic - Answers transient inward flow due to inactivation
Xenopus oocyte used for - Answers insertion of channels to observe different Vg channels
Staining methods - Answers - Golgi - black, whole neuron
- Nissl - cell body, all bodies
- in situ - cell body, differential staining
- Ab labling - target protein
- GFP - see all cells, green
- fluorescent - one cell, fluorophore
- fMRI
Reticular vs neural - Answers reticular - connected everything
neural - spaces, discrete
Chemical vs electrical synapses - Answers electrical - bidirectional, fast, connected, gap junction
(connexin)
chemical - unidirectional, common, slower
Otto Loewi experiment - Answers 1. stimulate heart with vagus nerve, slow down
2. heart 1 and 2 connected by solution - stimulate heart 1, heart 2 slow down after delay
Conclusion: soluble transmision
