| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
APS REFRESHER COURSE REPORT
Department of Biology, James Madison University, Harrisonburg, Virginia 22807
Abstract
Neuroscience has enjoyed tremendous growth over the past 20 years, including a substantial increase in the number of neuroscience departments, programs, and courses at the undergraduate level. To meet the need of new neuroscience courses, there has also been growth in the number of introductory neuroscience textbooks designed for undergraduates. However, textbooks typically trail current knowledge by five to ten years, especially in neuroscience where our understanding is increasing rapidly. Consequently, it is often important to supplement neuroscience and physiology textbooks with information about recent findings in neuroscience. To design supplementary educational material, it is essential first to identify the educational objectives of the program and the characteristics of the learners, which can differ dramatically between undergraduate and graduate or professional students. Four principles that may serve the selection and design of supplementary material for undergraduate neuroscience and physiology courses are that 1) material must be interesting to the undergraduates, 2) material should reinforce previously learned concepts, 3) students must be adequately prepared, and 4) the teacher and student must have sufficient appropriate resources.
Key words: teaching; education; neurobiology; lecture; problem
Neuroscience has enjoyed tremendous growth over the past 20 years, fueled in part by scientific discoveries and potential treatments of common neurological diseases as well as increased public (e.g., stem cell debates) and federal (e.g., "Decade of the Brain") awareness. The growth has been manifested in dramatic increases in attendance at the Society for Neuroscience annual meeting and in publications, journals, and lay news articles. In parallel, there has also been a substantial increase in the number of neuroscience departments, programs, and courses at the undergraduate level (3, 27). Between 1980 and 2000, the number of undergraduate neuroscience programs or departments has more than doubled. Most primarily undergraduate institutions now have neuroscience courses from both the biological and psychological perspectives. Furthermore, an organization dedicated to undergraduate neuroscience teaching, the Faculty for Undergraduate Neuroscience, was established in 1991 and has grown over the past decade. Specialized undergraduate neuroscience meetings, such as NEURON (Northeast Undergraduate Research Organization for Neuroscience) and SYNAPSE (Society of Young Neuroscientists and Professors of the South East) are also being developed to serve the growing need of undergraduate neuroscience students.
To meet the need of new neuroscience courses, there has also been growth in the number of introductory neuroscience textbooks designed for undergraduates as well as enhanced treatments in physiology textbooks. However, textbooks typically trail current knowledge by five to ten years. Although there is a trend toward more frequent revisions that incorporate the latest findings, a lag persists. This is especially true in neuroscience, where our understanding is increasing rapidly. Consequently, it is useful and often essential to supplement neuroscience and physiology textbooks and courses with information about recent findings in neuroscience. This is true at all levels, including medical, graduate, and undergraduate education.
To design supplementary educational material, it is essential first to identify the educational objectives of the program and the characteristics of the learners. Common objectives and characteristics of medical, graduate, and undergraduate students are described below, with other groups (e.g., allied health, bioengineering) generally falling within these limits. Medical students need factual knowledge relevant to patient care and to become skilled at a particular style of critical thinking. They are highly motivated and focused and well prepared by required coursework. Medical students also tend to be academically exceptional. Graduate students need broader knowledge and the ability to design and interpret scientific experiments. They are also well prepared, academically strong but with variable focus and motivation. Undergraduates, in contrast, rarely need specific knowledge (especially in a liberal arts environment). What knowledge and skills they will need in their future careers will be typically provided in their graduate or professional training. Instead, they need to develop their critical-thinking and problem-solving skills with the use of neuroscience as an ideal interdisciplinary framework (27). They are also both less and more variably prepared than medical or graduate students. Similarly, their motivation and academic aptitude are more highly variable than those of medical and graduate students.
Because of the differences in the educational objectives and characteristics of the students, designing supplementary materials for undergraduate neuroscience and physiology classes will differ significantly from those for medical or graduate school courses. The goal of the remainder of this article is to suggest principles by which supplementary materials relating to recent advances in neuroscience can be selected and integrated into an undergraduate neuroscience or physiology course.
DESIGN OF SUPPLEMENTAL MATERIAL ON RECENT ADVANCES IN NEUROSCIENCE
Selection, method of presentation, and choice of reading materials related to recent advances in neuroscience must be based on the educational goals of the course. Based on the above broadly described educational goals and characteristics of the learners, and with the understanding that not all undergraduate courses will be equally well served by these principles, four specific design principles for inclusion and use of recent advances in neuroscience are suggested.
Interest
In contrast to medical school courses and many graduate school courses, an undergraduate neuroscience course is usually an elective course. Consequently, it is incumbent on the teacher to make the course, and thus the supplementary materials employed, interesting to the student. As in any course, this can be done by selecting topics that are relevant to the students. Relevance for undergraduates, however, is likely to differ from relevance to medical students. For example, learning that a new variation of a leukotriene modifier can benefit asthmatics might excite medical students but put nonasthmatic undergraduates to sleep. So, what is relevant to an undergraduate? Anything on the cover of Time magazine (e.g., stem cells) might qualify, as would materials related to their particular lifestyle (e.g., learning, alcohol, sex, drugs).
Reinforcement of Principles
Because most undergraduate courses emphasize principles over facts, it is educationally valuable that the supplemental material reinforce the basic principles taught in the course. For example, botulinum toxins (discussed in Neurotoxins) provide an opportunity to reexplore and reinforce the mechanisms of presynaptic function. Unless this principle of reinforcement is explicitly addressed in course design, it is possible to present material without reinforcing principles. For example, a discussion of botulinum toxins could focus on medical and social implications which, although interesting and appropriate, might squander an opportunity to reinforce mechanisms of presynaptic function that were covered earlier in the semester. Alternatively, reviewing the literature on a particular topic from the perspective of reinforcement of earlier course material might lead to a different selection of aspects of the material to cover. For example, one might be tempted not to include neurotoxins that alter voltage gating of ion channels (5) in a discussion of neurotoxins because they are in the minority, but their inclusion in the course would allow reinforcement of voltage gating of ion channels.
Understandability
Undergraduates differ widely in their course preparation and aptitude. Consequently, it is essential that the supplementary materials be understandable to the entire class. Some topics meet this requirement better than others. For example, neurobiological genomics can be highly molecular, but many undergraduates may not have had a molecular biology class yet. In contrast, recent studies in which the movement of rats can be controlled by intracranial electrical stimulation can be taught to students with even limited background.
Accessibilty
Last, if faculty are going to teach supplementary topics and students are expected to study the supplementary materials outside of class, resources at the appropriate level for both teaching faculty and students must be accessible. Fortunately, there are now many excellent sources of materials available, in part available over the internet. These include a recent proliferation of scientific review journals, popular scientific magazines, news from scientific societies, meeting highlights, list-serves of recent advances, and online journal and news sources (specific suggestions are provided below). The free access to older (more than 6–24 months) journal articles offered by some publishers will become a tremendous resource for cost-effective inclusion of primary literature in courses.
To illustrate the application of the aforementioned four principles and to provide a limited number of topics that may be of use to teachers of undergraduate courses, two examples are provided below. Each example begins with a brief account of the relevant context and science to support subsequent discussion of its educational potential (references are provided at the end of the section). These accounts are not meant to be inclusive or authoritative reviews of the topic but rather to provide adequate background for subsequent discussion. Next, each topic is considered from the perspectives of the four principles proposed above. References are also provided for further reading.
Spinal Cord Injury
In the United States alone (22), traumatic spinal cord injury affects nearly 1% of the population and results in $7 billion in health care costs per year. Most victims are 15–25 years old, are male (4:1 over females), and received their injuries in motor vehicle accidents (42%). Public awareness has been enhanced recently by the highly publicized injury to the actor, Christopher Reeve.
Neuronal damage, which is sometimes restricted to the spinal gray matter, arises from both immediate and delayed processes. Initially, trauma to the spinal cord damages neural tissue and causes inflammation, leading to ischemia and edema. Immune responses further alter the course of injury, possibly in both beneficial and detrimental ways. Subsequently, excitotoxicity occurs, in which neuronal damage causes massive release of the neurotransmitter glutamate, which, in turn, opens postsynaptic calcium channels, leading to excessive calcium influx and cell death. In addition, over the following weeks, cells can undergo apoptosis, or programmed cell death, in response to neurochemicals released during injury. Apoptosis of myelin-producing oligodendrocytes results in loss of myelin and axonal conduction block. Current therapy consists largely of immediate (within 8 hours) intervention to reduce inflammation by steroid administration and possible surgical decompression as well as long-term rehabilitation to enhance any remaining function. Even small improvements in muscle control can lead to significant improvement in the patient’s lifestyle.
Although it was once believed that injured central nervous system neurons were incapable of recovery, recent advances in basic research have made restorative treatments a future possibility. The new approaches were underscored by a series of experiments that made international headlines outside the scientific community. For example, Cheng et al. (6) showed that bridging the spinal cord lesion in rats resulted in both enhanced growth of corticospinal neurons across the spinal cord injury and improved motor function. McDonald et al. (21) found that injection of immature nerve cells derived from mouse embryonic stem cells into spinal cord lesions resulted in functional improvement. The fundamental four obstacles to achieving recovery of function and some potential solutions are the following. 1) Neurons need to be prompted to regrow vigorously, which might be accomplished by administering the neuromodulator neurotrophic factor-3 (NT-3). 2) Once the growth cone reaches the site of injury, scar tissue and associated inhibitory chemicals such as Nogo proteins block the progress of regeneration. Solutions will require insertion of a "bridge" through which axons can pass or chemical block of Nogo. 3) Lost neurons might be replaced, perhaps by stem cell transplantation. 4) Pharmacological agents needed to accomplish the above need to be locally delivered, perhaps by implantation of cells genetically modified to secrete the appropriate therapeutic agent (12, 17, 20, 22, 26, 28).
Interest. Medical students are likely to find the overall frequency, costs, currently available therapeutic treatments, and potential outcomes most important to their studies. In contrast, undergraduates may be hooked by the age group of patients (largely their own), gender bias, and the recent, high-profile popular reports.
Reinforcement. The multiple aspects of spinal cord injury, treatment, and recovery provide a wealth of opportunities to reinforce basic neuroscience principles that were likely to have been covered earlier in the course and are covered in most introductory neurobiology textbooks. Selective damage to gray over white matter reinforces spinal cord neuroanatomy. Glutamate excitotoxicity revisits mechanisms of ion channels and second messengers in postsynaptic function. Apoptosis reinforces normal mechanisms of cell death during development. The use of NT-3 to induce neuronal growth can form the basis of a comparison of neurotransmitters, neuromodulators, and neurotrophic factors. Loss and replacement of myelin leads to review of action potential propagation in myelinated vs. unmyelinated axons. Neuronal replacement with stem cells raises fundamental questions about the specificity of neural connections. Finally, the use of genetically modified cells to deliver drugs brings up genetic engineering, a typically fascinating topic for undergraduates (assuming they have the background). In contrast, the clinical aspects, although interesting, are less likely to reinforce previously learned concepts at the undergraduate level.
Preparation. The basic neuroscience principles—neuroanatomy, synaptic function, action potential conduction, mechanisms of normal neuronal development, and genetic expression—are often covered in undergraduate neuroscience courses and should prepare the student well to understand spinal cord injury and its treatment. In contrast, some aspects of spinal cord injury are of less use for reinforcement. For example, the immunological aspects are important, but few undergraduates may be adequately prepared.
Resources. A book (42), numerous broad (17, 22, 28) and focused (12, 26) scientific reviews and original papers (4, 6, 21), popular magazine articles (20) and newspaper stories (2, 9, 43–45), and internet sites (7, 25, 30, 34, 36) are readily available to both teacher and student.
Neurotoxins
Neurotoxins, often derived from animal venoms, are among the most poisonous substances known. Although fatalities caused by animal venoms are rare in the United States, the medical impact in other countries is far greater. For example, in Burma, viper bites are the fifth leading cause of death (14). Medically, animal venoms are a challenge to treat because of their rapid action and diversity of structure and pathological actions, even among venoms from the same species living in different environments. On a positive note, recent research and medical practice have shown a use for toxins in reducing facial wrinkles associated with aging [dilute botulinum toxin with the trade name Botox (23)] and treating chronic pain and muscle weakness by capitalizing on the exceptional lethality of toxin molecules (31). Recent public attention following the events of September 11 has been focused on neurotoxins such as the botulinums, sarin, and ricin as biological weapons (11).
The neurobiology of neurotoxins focuses on their entry into neurons, the mechanisms by which damage is produced, how host animals resist their actions, and how neurotoxins can be used in medical treatment and research. Toxins that enter neurons, such as the botulinums that cause botulism poisoning, do so typically by endocytosis. In some cases, separate portions of the toxin are responsible for entry and intracellular actions. The deleterious effects of neurotoxins arise from an astonishingly wide variety of mechanisms. Extracellularly, toxins can block ion channels (e.g., tetrodotoxin block of sodium channels), allosterically modulate their permeability, or alter voltage gating. Intracellularly, neurotoxins can modify or destroy host proteins, block exocytosis of neurotransmitters, vesicle filling, or action potential generation, or damage DNA, resulting in altered protein synthesis and, in some cases, apoptosis. The intracellular actions can occur either pre- or postsynaptically. Host animals resist their own toxins in a variety of ways, including evolution of extra components on the target molecule that block binding of the toxin or by circulating factors that inactivate the toxin. Medical treatments have used neurotoxins in various ways. Toxins such as botulinums can be used in small doses to directly diminish neuromuscular excitation in treatments of spasticity and improve facial wrinkling. More recently, toxins have been chemically combined with antibodies, thereby using the antibody to selectively bind to the target cell and the toxin to kill it. In basic research, neurotoxins have long been used to understand function by selective block of individual components of synaptic transmission and action potential initiation (e.g., tetrodotoxin block of sodium channels), as well as for tracing anatomical connections (1, 5, 11, 15).
Interest. Although the medical aspects of neurotoxins are fascinating and relevant to medical students, undergraduates are likely to be hooked by the connection to biological terrorism, beauty treatments, and the types of animals from which venoms can be obtained.
Reinforcement. The mechanisms of action of neurotoxins can be used to reinforce nearly all aspects of cell-cell and intracellular communication. Together, toxins can interfere with action potentials, neurotransmitter release, postsynaptic binding, ion channel operation, second messengers, DNA expression, and a myriad of other intracellular proteins. Because of their exceptional specificity, neurotoxins can be used to reinforce the concepts of receptor binding. In courses that emphasize the experimental basis of neuroscience, neurotoxins [especially those that selectively block ion channels (15)], can be used in class, problems sets, or computer simulations designed to engage the student in experimental design.
Preparation. Most of the actions of neurotoxins require an understanding of cellular and molecular neurobiology, commonly taught in introductory neurobiology courses and often taught in biopsychology courses.
Resources. Books on neurobiology (15) and bioterrorism (19), broad (11) and focused (1, 5) scientific reviews, popular magazine articles (39), newspaper stories (29, 38), and internet sites (18, 35, 40, 41) are readily available to both teacher and student.
Other Topics
Spinal cord injury and neurotoxins are but two examples of recent advances with both high public and scientific interest as well as strong teaching potential in undergraduate neuroscience and physiology courses. Examples of other possibilities include "ratbots," which are rats guided to make certain movements by implanted electrodes (37, 46), recent progress on the pathology underlying Alzheimer’s disease and psychiatric disorders (13, 32), sugar addiction (16), and gaseous and nontraditional neurochemicals [e.g., D-serine, nitrous oxide, carbon monoxide (31)]. Although there are others, the problem is finding the topic and learning about it. Fortunately, there are several sources of information about current advances in neurosciences. These include the Society for Neuroscience Brain Briefings (33), the Dana Foundation publications (10), the National Institutes of Health (24), the Behavioral Neuroscience and Biopsychology list-serves (T. Yin, personal communication; contact this author, C. Cleland, for more information), the magazines Science News, Scientific American, and American Scientist, the science sections of major papers or news organizations such as the New York Times and British Broadcasting Company, international news articles available through Lexis-Nexis, as well as focused world-wide-web searches.
CONCLUSIONS
The educational goals of teaching neuroscience in medical, graduate, and undergraduate courses differ significantly. Consequently, it is not surprising that the choice of recent advances in neuroscience to include as supplementary materials to the primary textbook or course notes, as well as how to incorporate the topics, will also vary between educational groups. The aim of this article has been to suggest specific design criteria and provide resources for the use of recent advances in neuroscience in undergraduate neuroscience courses (both from the biological and psychological perspective). The four suggested design criteria—that materials must be interesting to the undergraduates, that materials should reinforce previously learned concepts, that students must be adequately prepared, and that the teacher and student must have sufficient appropriate resources—typically necessitate different choices for undergraduate, medical, or graduate students. In particular, I believe that using "hot topics" in neuroscience to reinforce earlier and often difficult concepts is the primary educational advantage of their inclusion in the course.
Acknowledgments
I thank Drs. Gayle Brosnan-Watters, Mary Lou Caspers, Jean Hardwick, Bart Hoebel, Karen Parfitt, and Tom Yin for helpful suggestions and Drs. Eric Wiertelak and Julio Ramirez for commenting on the manuscript.
Address for reprint requests and other correspondence: C. L. Cleland, Dept. of Biology, MSC 7801, James Madison Univ., Harrisonburg, VA 22932 (E-mail: clelancl{at}jmu.edu).
Received for publication August 26, 2002. Accepted for publication September 11, 2002.
REFERENCES
This article has been cited by other articles:
|
|
 |
|
  S. A. Azer Do recommended textbooks contain adequate information about bile salt transporters for medical students? Advan Physiol Educ, June 1, 2004; 28(2): 36 - 43. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
