Due December 1: Review paper due. In this paper you will identify the hypothesis, briefly discuss the results and indicate how the results supported the hypothesis. Then you should place this paper in the context of a larger scientific question and indicate what this paper contributes to that larger question. The additional papers that you choose should help you address that larger question. For example, one of the larger subjects was the molecular basis of memory. You may have chosen a paper that explored the role of an immediate early gene in this molecular pathway. Discuss how the scientists approached the identification of the immediate early gene (methods and results) and how identifying this pathway helps further elucidate this pathway. Finally, you should formulate other hypotheses that should be explored and identify techniques for addressing these questions.
Links for Vision and Visual Pathways
Bar Owl Articles
Sensitive Periods
Incremental Training
Due 10/13 for discussion and turned in by 10/15. Assignment will be on the tutorial, Interactions of Synaptic Potentials will be the second take home question and will be due on the day of the exam
Summation of EPSPs in passive postsynaptic membrane Follow the directions in the tutorial and produce two graphs (need a graphing application). One should plot time between two EPSPs and peak amplitude and the other should plot conductance vs peak amplitude.
Summation of EPSPs in post snaptic membrane with HH channels Follow the directions in the tutorial and answer questions in 3, 4, and 5.
Combining two subthreshold EPSPs. Provide a screenshot of the graphs produced in this exercise and generate a graph that plots amplitude of K+ current to the time difference between the two stimuli. Plot the results using the time differences from 0 to 27 ms. Explain the changes in amplitudes of the action potential and conductances. Explain how separated subthreshold stimuli can produce APs.
Effects of an IPSP on membrane excitability.
Provide a screenshot of the graphs produced when changing the conductance of the first inhibitory synapse. Change conductance from 0.5035 mS in 0.1 increments until 0.1035 and then go down in 0.01 increments. Explain your results.
Provide a screenshot of the graphs produced when changing the Erev of the inhibitory synapse in 5 mV increments from -80 mV to -55 mV. Explain your results. How are the changes in the inhibtory synapse affecting EPSP?
Due 10/8 for discussion and turned in by 10/13.
NIA The Neuromuscular Junction: How Do Voltage Gated Channels Affect the Shape of an EPP or an EPSP? Run the simulations where you are simulating an increase in the number of quanta that are released. Use keep Lines and produce a copy of the graph. Answer the following questions.
What is a quantum and why is increasing synaptic conductance a good way to simulate changes in quanta?
Explain the shape of the subthreshold EPP.
Compare EPPs in a passive and active patch. Produce traces (voltage vs time) to show a visual comparison of both.
NIA Postsynaptic Inhibition:
Reveal the IPSP, show the simulation that you did. Copy Postsynaptic voltage vs time and use keep lines to show the effects of the depolarizing and hyperpolarizing stimulus pulses.
Excite a Cell by Disinhibiting It, Define what is an off-response impulse and then compare the off response impulse to one generated by a depolarizing pulse. Provide a copy of the postsynaptic voltage vs time tracings. Describe the differences and supply reasons why they are different.
Are There Changes in Excitability Following an IPSP? Provide a copy of the postsynaptic voltage vs time tracings for both exercise 1 and 2 explain the results in both.
Due November 26: A review paper on your choice of one of the subjects below. Choose a primary literature article on the topic. A copy of this article must be in my hands by October 14, earlier if possible so that I can approve the article. You will need at least four other primary literature articles for you to write a more general review of the subject. If you have some ideas on topics that are not included below, please talk to me. You should be able to find something that grabs your attention. I will be posting more instructions and a copy of a review article for you to emulate.
Channelopathies--disesases caused by problems with channels or transporters.
Homeostatic mechanisms operating in neurons. I have some excellent suggestions for this topic.
The molecular basis of memory, or the circuits involved in memory.
The molecular basis of circadian rhythms
Chemoreception and how odors are coded
Somatotopic maps in the cortex.
9/29 NIA Chattering Ion Channels due for discussion. Turn in assignment 10/1 You may work in small groups of no more than 3, however, I need written indication of who did what on the assignment from each person. Answer any questions and the "make sure you understand" statements and provide copies of the normalized current plots for each increase that you do in the number of channels.
Neuroanatomy for Exam 2
In Photographic Axis, Sectional anatomy. some of the views are better at showing structures than others and some structures are found in multiple views. Make sure you check all views.
Visual system
Chemical senses
Cerebral cortex
Auditory system
Limbic system
Somatosensory
Group NIA projects
Modi, Tan, Ta, and Jeff-Eke on a) changes in diameter of unmyelinated axons on velocity of AP, b) effects of Na+ channel density on velocity of AP in myelinated axons and c) effects of wraps of myelin on velocity of AP
Pair, Bates and McNair on the effect of the number of wraps on velocity of the action potential.
Quick, Hicks and Haniff on the effect of Na+ channel density on velocity of the action potential. Note that this graph looks different than Modi et al. Why?
Jackson, Flournoy, Chisholm, and O'Neal on diameter of unmyelinated axon and velocity of AP
Nguyen and Olagoke on the effects of increases in membrane capacitance on velocity of AP
Shelnutt, Thompson and Nguyen on multiple sclerosis and AP velocity.
Equilibrium Potentials
In the experiment with glial cells, make a plot of the concentration of extracellular K+ vs the EK . Increase extracellular K+ in 5mM increments up to 130mM. Answer the questions in #5.
In the section on what determines the resting potential question #3, change gK (K channel density) and plot resting Vm and K channel density.
In the section on what determines the resting potential question #5, change [Na]o as instructed and answer twhy the resting potential so insensitive to the Na+ concentration.
The Na Action Potential
In the section on studying the effect of temperature on the action potential, plot duration of action potential vs temperature. Briefly describe how temperature affects the duration of the action potential.
In the section on How soon can the neuron fire again, plot delay between stimuli vs threshold stimulus.
Neuroanatomy for Exam 1
Sylvius 4 Photographic Atlas
Subcortical
Major cortical areas
Lobes
Cortical blood supplies