UBC Theses and Dissertations
The effects of procaine injections into MFB-LHA during self-stimulation of septum and barpress for food in the rat Madryga, Frederick John
The possibility that regions of the medial forebrain bundle-lateral hypothalamic area (MFB-LHA) are concerned with mediating the rewarding effect of electrical stimulation of the brain was examined by making unilateral injections of 2% procaine hydrochloride (2 ul) into this region during bar pressing for electrical stimulation in the septum or preoptic area. When the injection was made into the same side of the brain as the stimulating electrode, there was a strong suppression of self-stimulating rates as compared to the effect of isotonic saline injections, and the effect occurred with injections anywhere along the entire length of the MFH-LHA. The finding that the suppression was significantly less severe when the injections were made into the MFB-LHA on the side of the brain opposite to the electrode suggests that the suppression was not due to general disruptive effects. As a further control for nonspecific disturbances, similar injections were made in animals bar-pressing for food reward; the results showed that these injections suppressed bar-pressing for food but only when the injections were made into those regions of the MFB-LHA which have been shown to be involved in feeding behavior. These results suggest that the entire MFB-LHA is a part of a system mediating the rewarding effect of electrical stimulation of the septum and preoptic area.
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