Favorable effects of omega-3 polyunsaturated fatty acids in attentional control and conversion rate to psychosis in 22q11.2 deletion syndrome.

Omega-3-polyunsaturated-fatty-acids were suggested against cognitive dysfunctions and conversion to psychosis. However, a recent multicenter trial found no effect in reducing conversion rates in individuals at risk of developing schizophrenia. Patients' genetic heterogeneity and the timing of treatment might influence omega-3 efficacy. Here, we addressed the impact of omega-3 early treatment in both mice and human subjects with a 22q11.2 genetic hemi-deletion (22q11DS), characterized by cognitive dysfunctions and high penetrance of schizophrenia. We first tested the behavioural and cognitive consequences of adolescent exposure to normal or omega-3-enriched diets in wild-type and 22q11DS (LgDel/+) mice. We then contrasted mouse data with those gathered from sixty-two patients with 22q11DS exposed to a normal diet or supplemented with omega-3 during pre-adolescence/adolescence. Adolescent omega-3 exposure had no effects in wild-type mice. However, this treatment ameliorated distractibility deficits revealed in LgDel/+ mice by the Five Choice Serial Reaction Time Task (5CSRTT). The omega-3 improvement in LgDel/+ mice was selective, as no other generalized cognitive and non-cognitive effects were evident. Similarly, omega-3-exposed 22q11DS patients showed long-lasting improvements on distractibility as revealed by the continuous performance test (CPT). Moreover, omega-3-exposed 22q11DS patients showed less risk of developing an Ultra High Risk status and lower conversion rate to psychosis. Our convergent mouse-human findings represent a first analysis on the effects of omega-3 early treatment in 22q11DS. The beneficial effects in attentional control and transition to psychosis could support the early use of omega-3 supplementation in the 22q11DS population.

Internalization of Carbon Nano-onions by Hippocampal Cells Preserves Neuronal Circuit Function and Recognition Memory.

One area where nanomedicine may offer superior performances and efficacy compared to current strategies is in the diagnosis and treatment of central nervous system (CNS) diseases. However, the application of nanomaterials in such complex arenas is still in its infancy and an optimal vector for the therapy of CNS diseases has not been identified. Graphitic carbon nano-onions (CNOs) represent a class of carbon nanomaterials that shows promising potential for biomedical purposes. To probe the possible applications of graphitic CNOs as a platform for therapeutic and diagnostic interventions on CNS diseases, fluorescently labeled CNOs were stereotaxically injected in vivo in mice hippocampus. Their diffusion within brain tissues and their cellular localization were analyzed ex vivo by confocal microscopy, electron microscopy, and correlative light-electron microscopy techniques. The subsequent fluorescent staining of hippocampal cells populations indicates they efficiently internalize the nanomaterial. Furthermore, the inflammatory potential of the CNOs injection was found comparable to sterile vehicle infusion, and it did not result in manifest neurophysiological and behavioral alterations of hippocampal-mediated functions. These results clearly demonstrate that CNOs can interface effectively with several cell types, which encourages further their development as possible brain disease-targeted diagnostics or therapeutics nanocarriers.

Indicated prevention with long-chain polyunsaturated omega-3 fatty acids in patients with 22q11DS genetically at high risk for psychosis. Protocol of a randomized, double-blind, placebo-controlled treatment trial.

AIM: It has been found that long-chain omega-3 polyunsaturated fatty acids (PUFAs) reduce the risk of progression to first episode of psychosis (FEP) and may offer a safe and efficacious strategy for selective and indicated prevention in young people with ultra-high-risk (UHR) states. An opportunity for exploring the trajectory of FEP and for investigating the efficacy of preventive treatments exists in 22q11.2 deletion syndrome (22q11DS), which has a 30% psychotic transition rate. The fact that 22q11DS patients are more homogeneous than other UHR groups and are characterized by high level of negative symptoms provides a strong rationale for the use of PUFAs. The principal aim of the present trial is to investigate the effects of PUFAs in individuals with 22q11DS who are at UHR for developing FEP. METHODS: A prospective, randomized, double-blind, placebo-controlled, single-centre study design will be used. Eighty individuals aged 12-26 will be randomly assigned to two treatment conditions. RESULTS: The experimental group will receive PUFAs. The placebo group will receive paraffin oil. Standard clinical assessments and neuropsychological tests will be performed at baseline and at 8-, 12-, 26- and 52-week follow-up. Blood samples will be collected at baseline and after 12 weeks. This study is registered as an International Standard RCT, number 02070211. The corresponding author is supported by a NARSAD Young Investigator Award. CONCLUSIONS: This is the protocol of a planned study that aims to test the efficacy of PUFAs in the prodromal phase of FEP, in a specific syndrome where there is strong evidence that a high genetic load is involved in the disorder.

Working memory deficits, increased anxiety-like traits, and seizure susceptibility in BDNF overexpressing mice.

BDNF regulates components of cognitive processes and has been implicated in psychiatric disorders. Here we report that genetic overexpression of the BDNF mature isoform (BDNF-tg) in female mice impaired working memory functions while sparing components of fear conditioning. BDNF-tg mice also displayed reduced breeding efficiency, higher anxiety-like scores, high self-grooming, impaired prepulse inhibition, and higher susceptibility to seizures when placed in a new empty cage, as compared with wild-type (WT) littermate controls. Control measures of general health, locomotor activity, motor coordination, depression-related behaviors, and sociability did not differ between genotypes. The present findings, indicating detrimental effects of life-long increased BDNF in mice, may inform human studies evaluating the role of BDNF functional genetic variations on cognitive abilities and vulnerability to psychiatric disorders.

Genetic dissection of the role of catechol-O-methyltransferase in cognition and stress reactivity in mice.

The COMT (catechol-O-methyltransferase) gene has been linked to a spectrum of human phenotypes, including cognition, anxiety, pain sensitivity and psychosis. Doubts about its clinical impact exist, however, because of the complexity of human COMT polymorphism and clinical variability. We generated transgenic mice overexpressing a human COMT-Val polymorphism (Val-tg), and compared them with mice containing a null COMT mutation. Increased COMT enzyme activity in Val-tg mice resulted in disrupted attentional set-shifting abilities, and impaired working and recognition memory, but blunted stress responses and pain sensitivity. Conversely, COMT disruption improved working memory, but increased stress responses and pain sensitivity. Amphetamine ameliorated recognition memory deficits in COMT-Val-tg mice but disrupted it in wild types, illustrating COMT modulation of the inverted-U relationship between cognition and dopamine. COMT-Val-tg mice showed increased prefrontal cortex (PFC) calcium/calmodulin-dependent protein kinase II (CaMKII) levels, whereas COMT deficiency decreased PFC CaMKII but increased PFC CaMKKbeta and CaMKIV levels, suggesting the involvement of PFC CaMK pathways in COMT-regulated cognitive function and adaptive stress responses. Our data indicate a critical role for the COMT gene in an apparent evolutionary trade-off between cognitive and affective functions.