Autism spectrum disorder (ASD) is a type of neurodevelopmental disorder that occurs most frequently in early childhood, affecting approximately 1% of the global population. Currently, the elusive natu Show more
Autism spectrum disorder (ASD) is a type of neurodevelopmental disorder that occurs most frequently in early childhood, affecting approximately 1% of the global population. Currently, the elusive nature of the pathological mechanisms underlying ASD precludes the existence of a definitive, effective treatment approach. In this study, we have successfully generated a novel ASD rat model utilizing CRISPR/Cas9 technology, offering a promising platform for further investigation and potential therapeutic interventions. The model is characterized by two crucial point mutations occurring at key enzyme cleavage sites of brain-derived neurotrophic factor (BDNF), thereby causing disruptions in enzyme cleavage processes. The phenotypes of this rat model faithfully recapitulate the salient deficits frequently encountered in ASD patients, exhibiting impairments in social behavior, cognition, and anxiety, along with neuronal abnormalities with key brain regions, notably the hippocampus (HPC) and medial prefrontal cortex (mPFC). Through preliminary RNA-seq analysis, we found changes in gene expression patterns related to synapses and neuronal excitability in these areas, providing new insights into the pathogenesis of ASD. Furthermore, our utilization of 7,8-dihydroxyflavone (7,8-DHF), a robust enhancer for the upregulation of both BDNF and TrkB mRNA and simultaneously activates the BDNF-TrkB signaling pathway, appears to strengthen the BDNF-TrkB signaling cascade. This intervention modifies firing patterns of neuronal spikes and synaptic transmission, which may contribute to the amelioration of ASD-like social interaction behavior exhibited in BDNF Show less
This study examines neuroanatomical and molecular changes that may be responsible for cognitive impairment in the BTBR mouse model of autism. Compared to control C57Bl/6 mice, BTBR mice exhibited cogn Show more
This study examines neuroanatomical and molecular changes that may be responsible for cognitive impairment in the BTBR mouse model of autism. Compared to control C57Bl/6 mice, BTBR mice exhibited cognitive inflexibility, impaired in an operant learning task. MRI revealed significant brain abnormalities, including reduced cortical volume, smaller ventricles, and asymmetry in the dorsal hippocampus, accompanied by neuronal loss. BTBR mice also showed impaired cerebrospinal fluid dynamics, with reduced production and outflow. Molecular analysis revealed brain region-specific reduction in the expression of Bdnf exons 1, 2, 3, and 4 in untrained BTBR mice. Furthermore, learning induced changes in transcription of Bdnf exons exclusively in BTBR. Elevated proBDNF levels and an increased proBDNF/mature BDNF ratio in the frontal cortex and striatum indicated aberrant BDNF processing. These findings suggest that ASD-related cognitive impairments are linked to a complex of neurodevelopmental abnormalities, potentially connected to disrupted transcription, processing, and signaling of BDNF. Show less
Research on the different aspects of bipolar disorder (BD) in special populations, such as youth with autism spectrum disorder (ASD) is limited. This case-controlled study aimed to investigate the ser Show more
Research on the different aspects of bipolar disorder (BD) in special populations, such as youth with autism spectrum disorder (ASD) is limited. This case-controlled study aimed to investigate the serum levels of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), and nerve growth factor (NGF) in youth with ASD with and without comorbid BD. Forty young subjects (13.47 ± 2.89 years) diagnosed with ASD with comorbid BD were included in the case group, and 40 age/gender-matched subjects with diagnosis of ASD without any mood disorders were included in the control group. The serum levels of BDNF, GDNF, and NGF were measured using enzyme-linked immunosorbent assays. The Childhood Autism Rating Scale (CARS) was used to assess ASD severity in the subjects. Serum BDNF levels were significantly lower in the case group than in the control group (p = 0.002). No significant differences were observed in GDNF and NGF levels between the two groups (p > 0.05). The severity of ASD was significantly higher in the case group (p = 0.001). Low serum BDNF levels may be associated with BD comorbidity in youth with ASD. Given the difficulty in diagnosing BD in this population, serum BDNF levels may be a biomarker associated with the development/diagnosis of BD in youth with ASD. Further studies with larger sample sizes are required to validate these findings. Show less