ABSTRACT
Guanine nucleotide exchange factors (GEFs) play multiple functional roles in neurons. In a previous study, we reported that Arhgef4 (Rho guanine nucleotide exchange factor 4) functioned as a negative regulator of the excitatory synaptic function by sequestering postsynaptic density protein 95 (PSD-95). However, the role ofArhgef4 in behavior has not been examined. We performed comprehensive behavioral tests in knockout (KO) mice to investigate of the effects of Arhgef4 deficiency. We found that the expressed PSD-95 particle size was significantly increased in hippocampal neuronal cultures from Arhgef4 KO mice, which is consistent with the previous in vitro findings.Arhgef4 KO mice exhibited general motor activity and anxiety-like behavior comparable to those of the wild type littermates. However, spatial memory and object recognition memory were significantly enhanced in the Arhgef4 KO mice. Taken together, these data confirm the role of Arhgef4 as a negative synaptic regulator at the behavioral level.
ABSTRACT
OBJECTIVES: The overuse of the Internet among adolescents has increased dramatically in recent years, leading to pathological or problematic Internet use. Cognitive behavioral therapy (CBT) is known to be effective for the treatment of problematic Internet use, particularly for adolescents. The aim of the present study was to evaluate the therapeutic efficacy of group CBT for problematic Internet use in adolescents. METHODS: A total of 17 patients aged 12–17 years who met Young's diagnostic questionnaire criteria of problematic Internet use participated in a school-based eight-session group CBT program. The level of problematic Internet use among participating students was measured using Young's Internet Addiction Scale (IAS). Depression and anxiety levels were evaluated using the Children's Depression Inventory (CDI) and the State-Trait Anxiety Inventory (STAI), respectively. Each construct was assessed at baseline, immediately after the intervention, and at a one-month follow-up visit. Statistical significance was based on a p-value of < 0.05. RESULTS: Immediately after the program, the IAS, CDI, and State Anxiety Inventory (SAI) scores were significantly lower than before the program. At the one-month follow-up assessment, the IAS scores remained low, and the CDI and SAI scores were even lower than immediately after the program. CONCLUSION: Group CBT was effective for adolescents with problematic Internet use, and was also demonstrated to improve depression and anxiety.