Biogenic amines distribution in the brain of nervous and normal pointer dogs. A genetic animal model of anxiety

Nervous pointer dogs have been suggested as an animal model for pathological anxiety. In order to study possible disturbances in neurotransmitter functions in this animal model, we measured brain biogenic amines (norepinephrine, dopamine, and serotonin) and their metabolites in both nervous and normal dogs. Eight nervous and six normal dogs were behaviorally tested and later anesthetized and killed. Brains were removed and dissected while frozen using a punch technique. Samples were assayed using high-performance liquid chromatography (HPLC) with electrochemical detection. The nervous dogs had higher [NE] in the reticular formation and lower serotonin, and its metabolite 5-hydroxyindoleacetic acid, in the septal neuclei, indicating possible important differences in noradrenergic and serotonergic functions in the nervous dogs. There was a trend for lower [HVA] and [DOPAC] levels and a significantly lower [DOPAC]/[DA] ratio in the nervous dogs, suggesting decreased dopaminergic function.