Aims. Continuously active neurogenic regions in the adult mammalian brain are located in the subventricular zone (SVZ) of the lateral ventricles and the subgranular zone (SGZ) of the hippocampal dentate gyrus. The neurogenesis process is modulated by many factors e.g. growth factors, neurotransmitters and hormones. Neuropsychiatric drugs, especially antidepressants, mood stabilizers and antipsychotics may also affect the dynamics of the origin of neuronal cells. The purpose of the study was to determine the effects of long-term haloperidol treatment on adult rat neurogenesis at the level of canonical neurogenic sites.
Materials and methods. The studies were carried out on adult male Sprague-Dawley rats. Two groups of animals (5 in each) received, respectively, saline and haloperidol (2 mg/kg/day) by intraperitoneal injection for 28 days. The number of neuroblasts was evaluated using immunohistochemical detection of doublecortin (DCX) expressing cells. The total number of DCX-positive cells in the neurogenic zones was counted for each rat (which was the sum of cells from 10 slices) and the results were divided per length of the studied subependymal area (SGZ) and dentate gyri (SGZ) to obtain density of immunopositive cells per one millimeter of length.
Results. The results indicate that haloperidol has proneurogenic effects on the adult rat brain, especially in the SVZ, as the mean number of DCX-positive cells increased significantly in SVZ and there was a similar tendency in the SGZ.
Conclusions. We found that long-term treatment with haloperidol stimulated DCX-positive cell formation in the SVZ, which supports adult neurogenesis.