Neuroscience and biobehavioral reviews
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Neurosci Biobehav Rev · Dec 2001
Comparative StudyHippocampal involvement in the expression of kindling-induced fear in rats.
Kindling dramatically increases fearful behavior in rats. Because kindling-induced fear increases in magnitude as rats receive more stimulations, kindling provides a superb opportunity to study the nature and neural mechanisms of fear sensitization. Interestingly, these changes in behavior are accompanied by increased binding to inhibitory receptors and decreased binding to excitatory receptors in the CA1 and dentate gyrus regions of the hippocampus. ⋯ We found that FOS immunoreactivity was significantly decreased in the CA1 region, dentate gyrus, and perirhinal cortex of kindled rats compared to sham-stimulated rats. These results support our hypothesis that kindling-induced fear may be produced by inhibition within hippocampal circuits. They also suggest that neural changes within the hippocampus may be important for the sensitization of fear.