Abstract: Androgens play an essential role in the regulation of the structure and function of the central nervous system and are involved in different types of cognitive functions and behaviors. The low levels of androgens may alternate cognitive functions and result in neurodegenerative disorders. Regarding the important role of androgens in the central nervous system, androgen deprivation by castration may lead to synaptic and cognitive dysfunction. The focus of this study is specifically on experiments reporting the role of androgen deprivation by castration in changes of neuronal system functions that underlies depression, anxiety, synaptic plasticity, learning, and memory. Also, we tried to explain a possible mechanism by which castration changes synaptic plasticity, memory formation and cognitive functions. In this review article, Science direct, PubMed and Scopus databases were explored to provide original articles. Studies show that castration leads to anxiety, depression, memory impairments and synaptic dysfunctions. On the other hand, it has been reported that castration decreases the level of some synaptic markers such as BDNF, PSD-95, and SYN. Therefore, regarding a positive correlation between cognitive performances and synaptic markers, it can be suggested that castration can exacerbate memory impairments, synaptic dysfunctions, and cognitive defects by decreasing the level of the synaptic markers. However, it is necessary to conduct more investigation to understanding the effects of castration on the central nervous system.