Apomorphine-induced neurodegeneration in Mongolian gerbil hippocampus

Animal experiments using pharmacological agents acting on the dopaminergic system, such as apomorphine, have been used as suitable models of schizophrenia, based on the dopaminergic hypothesis of this disorder. To determine whether dopaminergic hyperactivity may produce neuropathological changes, young Mongolian gerbils were treated with apomorphine (0.45 mg/kg) and the hippocampal CA1 region was subsequently studied by transmission and scanning electron microscopy. Acute subcutaneous administration of apomorphine induced pronounced degenerative changes in hippocampal neurons, such as swollen dendrites and axons in the neuropil and swelling of synaptic endings with a decrease in the number of synaptic vesicles. In conclusion, we think that this animal model may provide important indications about a possible dopaminergic hyperactivation mechanism, that could produce pathological changes in the hippocampus similar to those encountered in psychotic patients.