مدیریت وب‌سایت

Mehdizadehfar, V., Ghassemi, F., Fallah, A., Mohammad-Rezazadeh, I., & Pouretemad, H. (2020). Brain connectivity analysis in fathers of children with autism. Cognitive Neurodynamics, 14(6), 781-793.

Abstract

Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder in which changes in brain connectivity, associated with autistic-like traits in some individuals. First-degree relatives of children with autism may show mild deficits in social interaction. The present study investigates electroencephalography (EEG) brain connectivity patterns of the fathers who have children with autism while performing facial emotion labeling task. Fifteen biological fathers of children with the diagnosis of autism (Test Group) and fifteen fathers of neurotypical children with no personal or family history of autism (Control Group) participated in this study. Facial emotion labeling task was evaluated using a set of photos consisting of six categories (mild and extreme: anger, happiness, and sadness). Group Independent Component Analysis method was applied to EEG data to extract neural sources. Dynamic causal connectivity of neural sources signals was estimated using the multivariate autoregressive model and quantified by using the Granger causality-based methods. Statistical analysis showed significant differences (p value < ۰.۰۱) in the connectivity of neural sources in recognition of some emotions in two groups, which the most differences observed in the mild anger and mild sadness emotions. Short-range connectivity appeared in Test Group and conversely, long-range and interhemispheric connections are observed in Control Group. Finally, it can be concluded that the Test Group showed abnormal activity and connectivity in the brain network for the processing of emotional faces compared to the Control Group. We conclude that neural source connectivity analysis in fathers may be considered as a potential and promising biomarker of ASD.

Mansouri, M., Pouretemad, H., Roghani, M., Wegener, G., & Ardalan, M. (2020). Autistic-Like Behaviours and Associated Brain Structural Plasticity are Modulated by Oxytocin in Maternally Separated Rats. Behavioural Brain Research, ۱۱۲۷۵۶.

Abstract

Background

Early psycho-social experiences influence the developing brain and possible onset of various neurodevelopmental disorders, such as Autism Spectrum Disorder (ASD). ASD is characterized by a variety of brain abnormalities, including alteration of oxytocin receptors in the brain. Recently, early life adverse experiences, such as maternal separation (MS), have been shown to constitute risk factors for ASD in preclinical studies. Therefore, the main aims of the current study were to i) explore the association between onset of autistic-like behaviours and molecular/structural changes in the brain following MS, and ii) evaluate the possible beneficial effects of oxytocin treatment on the same parameters.

Method and Material

Male rats were exposed to the maternal separation from post-natal day (PND) 1 to PND14. After weaning, daily injections of oxytocin (1 mg/kg, ip) were administered (PND 22-30), followed by examination of autism-related behaviours at adolescence (PND 42-50). Brain structural plasticity was examined using stereological methods, and the plasma level of brain derived neurotrophic factor (BDNF) was analysed using ELISA.

Results

We found that maternal separation induced autistic-like behaviours, which was associated with increase in the hippocampal CA1 stratum radiatum (CA1.SR) volume. In addition, we observed increase in the infralimbic brain region volume and in the number of the pyramidal neurons in the same brain region. Maternal separation significantly increased the plasma BDNF levels. Treatment with oxytocin improved autistic like behaviours, normalized the number of neurons and the volume of the infralimbic region as well as the plasma BDNF level (p < 0.05).

Conclusion

Maternal separation induced autistic-like behaviours, brain structural impairment together with plasma BDNF level abnormality, which could be improved by oxytocin treatment.