Septal hyperreactivity: A multivariate analysis of neuroanatomical correlates

A multivariate data analysis was used to obtain a quantitative comparison of the behavioral syndromes following different lesions, all of which have been described as producing hyperreactivity. Male rats were tested preoperatively and after radio frequency lesions in the septum, medial preoptic area, total preoptic area, medial olfactory stria, and ventromedial hypothalamus. Lesions of the total preoptic area produced a hyperreactivity similar to that found after septal lesions, while lesions of the medial preoptic and the medial olfactory stria were generally ineffective. Destruction of the ventromedial hypothalamus produced a slight hyperreactivity, but not as great as that following septal lesions. The results are discussed in terms of a common neuroanatomical and/or biochemical pathway mediating the different types of reactivity.