Modifications of serotonergic and adrenergic receptor concentrations in the brain of aggressive Canis familiaris

The aim of the study was to measure β-adrenergic (β-AR) and serotonergic (5-HTR) receptor concentrations in different brain areas (frontal cortex, hippocampus, hypothalamus and thalamus) of normal and aggressive dogs. Eight adult male dogs, 4.2±0.6 years old, showing no clinical signs but aggression, were used for the study. Eight healthy male dogs, 4.4±0.8 years old, with no history of neurological and/or behavioural disorders and accidental death, were used as controls. The whole frontal cortex, hippocampus, thalamus and hypothalamus were collected after euthanasia and plasma membrane fractions obtained by ultracentrifugation. β-AR and 5-HTR were measured by binding assays using specific radioligand [(−)[ 3H]CGP 12177 and 5-hydroxy[ 3H]-tryptamine trifluoroacetate, respectively]. A significant decrease in β-AR levels was observed in the frontal cortex ( P=0.001), hippocampus ( P