Hunger and the Fat Rat Module Map

Purpose  To demonstrate the role of the hypothalamus in the control of eating behavior in rats.

Summary  This module demonstrates the use of electrical stimulation and destructive surgery as tools in exploring the functions of the rat brain. After background information on methodology is presented, students simulate an experiment on weight regulation. First students move an electrode to either the ventromedial or the lateral region of the hypothalamus, and they then select a level of current that will stimulate or destroy the area. The effect on the rat's daily food intake and body weight is graphed. By repeating the experiment with different rats under different conditions, students should be able to infer that destruction to the VMH will cause a rat to eat more, while destruction to the LH regulates the "set point" to a lower level of body weight. In contrast, stimulation of the LH induces eating, while stimulation of the VMH inhibits eating. After the student has finished experimenting, the module warns against concluding that a "hunger center" or "satiety center" has been demonstrated.
Introduction
Electrolytic research procedures
Purpose of this module
The hypothalamus
Stereotaxic apparatus
 		Procedures
Experiment simulation
Cautions
Summary
References


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