Behavioral screening of two mouse lines selected for different brain weight

Potential Cross Talk between Autism Risk Genes and Neurovascular Molecules: A Pilot Study on Impact of Blood Brain Barrier Integrity

Autism Spectrum Disorder (ASD) is a common pediatric neurobiological disorder with up to 80% of genetic etiologies. Systems biology approaches may make it possible to test novel therapeutic strategies targeting molecular pathways to alleviate ASD symptoms. A clinical database of autism subjects was queried for individuals with a copy number variation (CNV) on microarray, Vineland, and Parent Concern Questionnaire scores. Pathway analyses of genes from pathogenic CNVs yielded 659 genes whose protein-protein interactions and mRNA expression mapped 121 genes with maximal antenatal expression in 12 brain regions. A Research Domain Criteria (RDoC)-derived neural circuits map revealed significant differences in anxiety, motor, and activities of daily living skills scores between altered CNV genes and normal microarrays subjects, involving Positive Valence (reward), Cognition (IQ), and Social Processes. Vascular signaling was identified as a biological process that may influence these neural circuits. Neuroinflammation, microglial activation, iNOS and 3-nitrotyrosine increase in the brain of Semaphorin 3F- Neuropilin 2 (Sema 3F-NRP2) KO, an ASD mouse model, agree with previous reports in the brain of ASD individuals. Signs of platelet deposition, activation, release of serotonin, and albumin leakage in ASD-relevant brain regions suggest possible blood brain barrier (BBB) deficits. Disruption of neurovascular signaling and BBB with neuroinflammation may mediate causative pathophysiology in some ASD subgroups. Although preliminary, these data demonstrate the potential for developing novel therapeutic strategies based on clinically derived data, genomics, cognitive neuroscience, and basic neuroscience methods.

Exploratory behavior of F2 crosses of mouse lines selected for different brain weight: a multivariate analysis

Principal component analysis of behavioural measures together with body and brain weight of hybrid F2 mice crosses between two lines selected for large (LB) and small (SB) brain weight yielded eight-factor solution explaining 75.1% of total variance. Two of eight factors had sufficient loading on brain weight and several behavioural measures. The factor analysis showed that, among F2 hybrids, mice with larger brain weight were characterised, in open-field test, by higher scores of locomotion in the periphery of arena and of rearing, as well as less frequent grooming and freezing than mice with smaller brain weight. F2 hybrids with larger brain weight moved faster and displayed stereotyped behaviour in the cross-maze test more frequently. In general, this diversity is in accord with the behaviour differences between parent LB and SB lines. The results show that, in mice fear-anxiety and stereotypic behaviours, which are known to interfere with normal exploration and learning of the environment, are causally connected with brain weight.