Oleic Acid Produces Motor Incoordination and Hypoactivity in Infant Wistar Rats Through GABAA Receptors

A mixture of eight fatty acids (linoleic, oleic, palmitic, stearic, myristic, elaidic, lauric, and palmitoleic acids) at similar concentrations that have been identified in human amniotic fluid exerts anxiolytic-like effects similar to diazepam in adult Wistar rats through actions at γ-aminobutyric acid-A (GABAA) receptors, but unknown is whether any of these fatty acids exerts a predominant action over the others in infant rats. Of these fatty acids, some actions of oleic acid have already been identified, and it is one of the most abundant in amniotic fluid. Therefore, the aim of this study was to explore the effect of oleic acid on anxiety-like behavior and motoric activity in infant rats. To explore sedative actions, 28-day-old Wistar rats received 80-320 μg oleic acid or a sedative dose of diazepam (5 mg/kg). In a dose-response study, other groups of rats were injected with 10-80 μg oleic acid or 1 mg/kg diazepam. In an interaction study, rats that received oleic acid were pretreated with the GABAA receptor antagonists picrotoxin or flumazenil to explore the participation of this receptor in the effects of oleic acid on behavior in the elevated plus maze, rotarod test, and open field test. Oleic acid produced sedative effects but did not exert any anxiolytic-like actions. Hypoactivity and motor incoordination that were induced by oleic acid were blocked by flumazenil and picrotoxin. In conclusion, oleic acid reduced locomotor activity and motor incoordination through actions at the GABAA receptor.