Expression of the PV‐ and BDNF‐immunoreactive neurons in the brain regions associated with emotion and cognition in animal models of autism

Abstract

In this study, immunohistochemical and western blot methods were used to examine the expression of the PV‐ and BDNF‐ immunoreactive neurons in the amygdala, prefrontal cortex, hippocampus and sensory cortex in animal models of autism, which were obtained in offspring of the Wistar rat by means of a single intraperitoneal injection of 600mg/kg sodium valproate (VPA) at the day of 12.5 after pregnancy and by a method of repeated cold stress. The immunohistochemical results showed that PV‐immunoreactive neurons in the amygdala,prefrontal cortex and hippocampus of autism models changed in various degrees in shape and size of the soma of the neurons and in density and length of the process of the neurons; the number of the BDNF‐immunoreactive neurons of the sensory cortex in model group was decreased, and the soma of the neurons were smaller and the processes were shorter in model group at postnatal day of 35 than those of control group; while the morphology of the BDNF‐immunoreactive neurons in model rats tended to be normal at postnatal day of 49. The western blot showed the corresponding results to those by the immunohistochemical methods. The present results suggested that the PV‐containing interneurons might play an important role in autism, and the changed PV interneurons probably weaken their inhibition to the pyramid neurons in the brain circuits that were related to autism; while the BDNF may be closely related with the abnormal development of the brain in autism.