Reduced density of VGF immunoreactive neurons in the hypothalamus of patients with schizophrenia

VGF nerve growth factor (NGF) inducible protein is involved in the energy homeostasis, pain modulation, sexual behaviour, gut contraction and has also antidepressant effects. Interestingly, VGF fragment 23–62 was consistently increased in cerebrospinal fluid (CSF) in two independent groups in the first onset of drug naïve schizophrenic patients (Huang et al.). VGF is widely expressed in CNS neurons. In the present study we investigated whether alterations of VGF immunoreactivity can be detected in the hypothalamus of schizophrenic patients. The density of VGF positive neurons was examined in paraventricular (PVH) and supraopticus (SON) nuclei of 20 patients with schizophrenia and 19 neuropsychiatric healthy control subjects. Our study showed a significant difference in the neuronal density in the left PVN (P = 0.002) and SON (P = 0.008) and a non-significant difference in the right PVN (P = 0.149) and in the right SON (P = 0.327). While Huang et al. detected in the prefrontal cortex a strong expression of VGF in four out of eight patients, the significant decrease in our study could be the reason for the increased secretion of this granin into the CSF during the schizophrenic disease. Consequently, VGF might play an important role in schizophrenia.