Histofluorescent identification of indoleamine-concentrating brain loci associated with intraspecies, reflexive biting and locomotor behavior in olfactory-bulbectomized mice.

ABSTRACT

The histofluorescent identification of indoleamine (serotonin)-concentrating neurons and the changes induced by olfactory bulbectomy (Obx) were correlated with reflexive biting and locomotor behavioral activities in grouped male mice. Between 2 and 35 days post-Obx, an increase in the number and fluorescent-intensity of indoleamine-containing neurons was identified in the olfactory tubercle, lateral olfactory tract (bed neurons) and piriform cortex. Neurons in the nucleus accumbens and anterior olfactory nucleus also demonstrated increased histofluorescence by Day 35 post-Obx as compared with controls, but to a lesser extent than observed in the other olfactory loci. The increase in serotonin concentration was inversely related to locomotor activity and directly correlated to biting behavior in Obx mice. These results demonstrate that the development of this type of intraspecies aggression is temporally correlated with an enhanced serotonin histofluorescence in specific forebrain, olfactory regions in mice.