The Electrical Stimulation of Brain Pleasure Centers
Videoclips of Experiments
By Silvia Helena Cardoso, PhD

The videoclips available below illustrate classical experiments carried out in the laboratory of Prof. James Olds in the sixties, using rats with metallic electrodes implanted permanently into some brain structures (hypothalamus) which were shown to be responsible for pleasure. When electrically stimulated by the animal itself, by means of an electical switch attached to a lever, this caused a prolonged repetition of the so-called self-stimulation behavior.

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Video 1(19 sec.)

In this experiment, the rat learns to push a lever in order to introduce a rewarding stimulus by means of electrical stimulation of certain poits of the brain which cause pleasure. Each blinking of the yellow light shows that a stimulation has been delivered. In this way, Olds was able to demonstrate the existence of specific pleasure centers in the brain.

Video 2(8 sec.)

Here you will see a rat learning how to push a lever situated at one end of a long cage, in order to deliver an electrical stimulus to its brain pleasure center. Then, the rat must cross through an electrified grid in the cage's floor, in order to press another self-stimulation leverr at the other end. The rat endures a strong painful electric shock to its paws to cross the cage and get the stimulation. Normal rats, even when very hungry, will not do this to get food.

Video 3(13 seg.)

This rat is dependent on morphine. It has learned to get a drop of it every time a lever is pressed. This behavior is repeated continuously and ever so stronger, in a way similar to the brain self-stimulation. 

See also in this issue:

Extracted and abridged from original films by James Olds, University of Michigan, Michigan, 1962
Coordination and creation: Dr. Silvia Helena Cardoso, Editora-in-Chief, Brain & Mind
Video capture: Gisele Felippe Rodrigues, webmaster, Center for Biomedical Informatics, State University of Campinas. 
RealVideo server: Courtesy of WebPraxis International

Brain & Mind Magazine 3(8), Jan/March 1999
An Initiative of the Center for Biomedical Informatics
Copyright (c) 1998 State University of Campinas, Brazil
Published on 18/Jan/1998