This project addresses the basic need in neuroscience education for a
means to illustrate and explore the processes that underlie neuronal function.
To meet this need, we are creating a series of laboratory simulation exercises
designed to advance neuroscience education by
Project
Goals and Background
Strengths
Starting Point
Outline
Evaluation
Dissemination
Integrating these
exercises into the curriculum
Simulations and "wet lab"
experiments
NEURON
Why NEURON?
NEURON's home page at
Yale
The Development Team
Ted Carnevale, Department of Psychology, Yale University
Michael Hines, Department of Computer Science, Yale University
David Jaffe, Division of Life Sciences, University of Texas, San Antonio
The primary aim of this project is to
create a set of laboratory simulation exercises, with an accompanying manual,
that will advance neuroscience education. The emphasis is on education at the
undergraduate level, but these exercises should also be suitable for
introductory graduate level courses.
An important secondary aim of this project
is to make a powerful simulation tool available to neuroscience students early
in the course of their education. NEURON is used widely in research, so
students who go on to advanced studies will experience a double benefit from
these exercises.
Simulations for neuroscience education
Neuronal function involves the interaction
of chemical and electrical signals that are distributed in space and time.
These signals are generated by mechanisms that typically have complex dynamics
and nonlinearities. Therefore a student's introduction to neuronal function
should not be limited to static figures on a printed page.
What is needed is a means to illustrate and
explore the processes that underlie the function of nerve cells and brain
circuits. Integrating properly selected and designed simulation exercises into
the neuroscience curriculum can increase motivation, enhance correct intuition,
and help students visualize concepts. The simulations we are developing are
designed to meet this need.
Empowering the next generation of Neuroscientists
For the first time in the history of
neuroscience education, a simulation tool that is used widely in neuroscience
research will be introduced to undergraduate students. The potential importance
of this becomes clear when one considers that SPICE and other simulation tools
appropriate for the physical sciences have long been available on
microcomputers to engineering undergraduates, whereas until recently no
research-grade neural simulator has been accessible to undergraduates. This
disparity is even more striking when one reflects on the fact that the dynamics
and nonlinearities of neuronal mechanisms are more complex than those
encountered by electrical engineering undergraduates (Weiss et al. 1992).
Reference Weiss, T.F., Trevisan, G., Doering, E.B.,
Shah, D.M., Huang, D. and Berkenblit, S.I.. Software for teaching physiology
and biophysics. J. Science Education and Technology 1:259-274, 1992.
These exercises
Limitations of present "educational simulators"
Unlike engineering or physics students, who acquire both knowledge and
skills while they do their homework with SPICE (Nagel 1975), Mathematica
(Wolfram Research, Inc.), or MatLab (The MathWorks, Inc.), a student who uses
one of the present "educational simulators for neuroscience" is not
simultaneously learning about a tool that will be helpful in his or her future
career.
All
assume a single compartment.
Most are limited to Hodgkin-Huxley currents and simple synaptic conductances.
Most
are linked to only one text.
All are limited to one or two platforms.
The
exercises we are developing have none of these limitations.
Reference
Nagel, L.W.. SPICE2: a computer program to simulate
semiconductor circuits. ERL Memo No. ERL-M520, Electronics Research Laboratory,
Berkeley, CA, University of California, May, 1975.
In the fall of 1994, David Jaffe first used
NEURON in his laboratory course in neurobiology for undergraduates at the
University of Texas, San Antonio. The exercises he created covered a wide
variety of topics including electrotonus, synaptic plasticity, and
intracellular calcium dynamics. The simulations were implemented using NEURON
under UNIX and had a simple text-based user interface with oscilloscope-like
graphic output.
In one laboratory session, students
examined the properties of conductance-increase synapses. One of the tasks was
to examine the effects of synaptic location on synaptic potency (ability to
trigger action potentials) and measurements made at the soma. Since the
simulations were constructed with NEURON, the students were able to control
synaptic placement. This helped them to immediately visualize the effects of
synaptic location on voltage attenuation and the ability of synaptic inputs to
fire the cell. This would not have been possible with existing educational
simulators.
Students then explored non-linear summation
and the effect of driving force on the amplitude of synaptic potentials. They
also compared measurements of synaptic potentials and synaptic currents to
learn how to use quantitative methods to study the biophysics of synapses.
Experiments such as these are simply not
feasible in a typical "wet" neurobiology laboratory. However, in
conjunction with classical experiments, such as measuring end-plate potentials
from frog muscle, these simulations can be used to extend and enhance the wet
lab experience.
Development of the exercises will be a
pragmatic, iterative process guided by an assessment of needs derived from our
own in-classroom experience, a formal evaluation mechanism, and the
recommendations of an Advisory Panel. The Advisory Panel includes educators who
have considerable experience teaching neuroscience to undergraduates. Some of
our advisors have themselves developed software for neuroscience education.
Their input will be indispensable in topic selection and in
"fine-tuning" the exercises.
Achieving the objectives of this project entails five related tasks:
1. Selecting topics. Topic selection will be motivated only by pedagogical considerations and
will not be restricted by mere technical factors, since far more sophisticated
simulations than these are feasible using NEURON on microcomputers that
currently cost $1000 or less.
2. Designing and implementing the
exercises. Each exercise will have both a text
component and a software component.
The text component will contain a statement
of the purpose of the exercise, pointers to background material in several
neuroscience textbooks, and a brief description of internals of the model. We
do not intend to produce a stand-alone neuroscience textbook, but a short
statement of the key scientific principles that are involved will be included,
with citations of the primary literature as appropriate. This will be followed
by a set of questions and suggested computer activities to motivate and convey
the didactic content of the exercise.
The software component will implement a model that embodies the
principles that are under consideration, and will have a student-friendly,
graphical user interface. We will try to facilitate incorporation of the
exercises in undergraduate neurobiology "wet lab" courses by designing
the models to emulate aspects of common experimental preparations.
3. Keying the exercises to
widely-used neuroscience texts. The final selection of texts will depend on the best
current educational practice. This list will be strongly influenced by needs
assessment conducted with our Advisory Panel.
4. Evaluating and revising the exercises is discussed here.
5. Communicating project results and
distributing the exercises is covered here.
The educational utility of these exercises
will be assessed by their impact on student performance and attitudes regarding
neuroscience. We want the exercises to focus on learning rather than the
computer, and are particularly interested in optimizing the ratio of effort to
insight. Therefore we must know the results of "hands-on" use in many
classrooms other than ours. For overall guidance in project evaluation, we have
enlisted the assistance of a consultant who is an expert in the evaluation of
the use of computers in education. We are also getting feedback from a panel of
advisors who have considerable experience teaching neuroscience to
undergraduate and graduate students at several colleges and universities
5. Communicating project results and
distributing the exercises. Communications between the development
team and the Advisory Panel will be facilitated through the Internet. Research users
of NEURON are already supported through an extensive set of Web pages and an
electronic "mailing list." New revisions of the educational software
and text will be distributed to the advisors via a new family of WWW
"project pages," and we will establish a project newsgroup to enable
communication among the development team and advisors.
We will also bring the results of this
project to the broader community of neuroscience educators, in part through the
Internet and in part through poster presentations and special interest
gatherings at the annual meetings of the Society for Neuroscience.
One direct outcome of this project will be
a manual that documents the completed exercises. To help educators tailor these
simulations to their own needs, the manual will also contain a short tutorial
on how to modify and create models with NEURON. We will arrange for the manual
and software to be distributed by a major scientific publisher. Initial
discussions have already begun with several publishers, and all are quite
enthusiastic about this project.
Measures that we are taking to help
integrate these exercises into the curriculum include:
These measures will increase the utility
and availability of these exercises to all students who are exposed to
neuroscience.
One item that will receive special
attention is how to coordinate these exercises with "wet lab"
experiments. The educational process ideally should include both simulations
and wet lab. The value of wet lab experiments can be reinforced and amplified
by simulations that include thought-provoking "what if" scenarios. It
will be highly desirable for future neuroscientists to be able to combine these
investigational strategies in their research activities, whether independently
or in collaboration with others. Regardless of whether one is primarily an
experimentalist or a modeler, it is useful to have some experience with both.
Therefore some or all of the simulation
exercises will be designed to be complementary to actual experiments on
preparations that are appropriate for undergraduates, e.g. frog sciatic nerve,
crayfish neuromuscular junction. The strategy we ultimately use will depend on
our own in-class experience and the recommendations of our Advisory Panel.
To accommodate differences in emphasis,
selection of topics, and teaching style, it is important to give teachers the
ability to tailor simulations to their own classroom and laboratory needs.
Therefore we will offer assistance to those members of our Advisory Panel who
are interested in modifying or creating their own simulations. Furthermore, a
section of the manual will include examples that illustrate how to modify the
model source code. In this manner we hope to draw students from using
"canned simulations" into creating their own models.
The outcome of this project will be a set
of exercises that can be used in conjunction with almost any undergraduate
lecture or lab course in order to stimulate student interest and participation,
illustrate concepts that are otherwise difficult to grasp, and foster correct
intuitions about important mechanisms in neurobiology.
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