Biological Sciences 300/301, Smith College | Neurophysiology

Checklist for Labs 9-12:
Projects on the Crayfish Swimmeret System

UPDATED: March 30, 2017

For the remainder of the semester, the laboratory will be devoted to a single experimental project. You will have time to plan, refine, and repeat an experiment. All projects will investigate some aspect of the crayfish swimmeret central pattern generator. We explored potential experiments and some background for the projects in our reading and discussion in Lab 8.

Two assignments are associated with the lab project: a one-page abstract and a presentation.

Schedule and assignments.

Week 1: Establish a basic preparation to record the swimmeret pattern.

Record from the first roots of the abdominal nerve cord, using either a semi-intact or an isolated nervous system, as described below under Experimental Methods. Try to elicit the swimmeret pattern using an appropriate dose of carbachol or proctolin. If possible, gather your first data.

Weeks 2 -3: Refine and repeat your experiment, modifying your plan if necessary.

Record and analyze data, taking care to show that the results are reproducible. If you are testing the effects of a drug, demonstrate that the effects you see are truly the result of the treatment, and not just a spontaneous response or a sign of deterioration of the preparation. (Usually, being able to wash out the drug and restore the preparation's previous state is a suitable control.) If you are investigating timing or coordination between ganglia, measure and plot your data for each experiment to see if different experiments are consistent.

Feel free to check out what other groups are doing, and to offer and receive advice. Working on the same basic preparation allows us to share information and learn from each other.

Week 4: Summarize your experimental work in an abstract and a computer-based presentation.

ABSTRACT. You and your lab partner(s) should write an abstract together, with a title and your full names at the top. The abstract tells us succinctly what you did and what you found. It is limited to ONE page, single-spaced. You may include diagrams or sample records within that page. Write informatively, for the students who will read your abstract in future years. Please email me ( a copy of your one-page abstract with embedded figures (as a Word, Pages, or PDF file) by the evening before your last lab day (eg, Monday evening for Tuesday lab, Tuesday evening for Wednesday lab). Abstracts will be placed online for our class and future classes.

PRESENTATION. Create an informal computer-based presentation about your project jointly with your lab partner(s). Tell us the project's purpose, possibly a little about what is already known, the important aspects of your methods (including pitfalls to watch out for), and what you found out. If you have useful data, we'd like to see selected records or graphs that summarize your results. You can use LabChart to present examples of your data dynamically.

Posters and abstracts from previous classes are available on our Moodle site.

Some comments on grading. Your experiments, your project abstract, and your presentation will all be components in the grade for the laboratory course, along with your portfolio of data from the first part of the semester. Lab projects will be graded on the basis of the sensibility and skill with which the experiments were designed and carried out. It is understood that in some cases, any useful results may represent a triumph. A good project will have been thought through clearly, with data analyzed to demonstrate that responses are repeatable, related to the magnitude of the treatment, and (if possible) reversible. The presentation of the project should be clear, organized, and informative.