The Restoration of Social Defects in Schizophrenic Mice by Plant Exposure

Abstract

Schizophrenia is a serious psychotic disorder caused by both individuals' genetic background and their living environment. However, how cognitive and negative symptoms can be treated is still a challenge since most anti-psychotic drugs are only effective for positive symptoms. Previous epidemic studies have demonstrated that plant exposure could decrease the risk of schizophrenia and shorten the length of psychiatric hospital admissions for patients. However, it is still unknown whether plant exposure could improve cognition-related defects in schizophrenia, with no related animal studies. In the present study, we first induced a schizophrenia mice model by giving mice long-term (2 weeks) injections of the antagonist of the NMDA receptor: MK801. We then raised the animals in environments containing plants (4 weeks) including Epipremnum aureum and rosemary, and tested their locomotive, anxious and social behaviors. We found that plant exposure did not change the locomotion behaviors of wild-type animals, but significantly reduced the schizophrenia-related social and anxious behaviors in the schizophrenic animals. In addition, we tested the expression of c-Fos in animals exposed to plants after social behavioral testing. We found that the deficits in c-Fos expression in both the hippocampus and prefrontal cortex were partially rescued after plant exposure. These results indicate plant exposure will be a new tool to improve the clinical deficits of schizophrenia.