Genes, Brain and Behavior

Only depressed patients carrying the FKBP5 rs1360780 risk allele showed GR resistance compared with healthy controls, measured by GR-induced FKBP5 mRNA induction in blood cells.

Genetic variation in the α4 subunit of the nicotinic acetylcholine receptor is nominally associated with nicotine dependence liability.

When examining the relationship between adenosine A_2A receptor (ADORA2A) gene polymorphisms and ADHD traits in a population-based sample of 1747 twins, results showed nominal associations between ADHD traits and three SNPs in the ADORA2A gene: rs3761422, rs5751876 and rs35320474. For one of the SNPs, rs35320474, results remained significant after correction for multiple comparisons. These results indicate the possible involvement of the ADORA2A in ADHD traits, a plausible notion as adenosine plays a role in ADHD-related neurobiological mechanisms such as dopamine neurotransmission and regulation of alertness. However, these results should be viewed as preliminary and more studies replicating the present results are warranted before this association can be confirmed.

We find ADAR2 transgenic mice display a preference for diets with high fat content and their overeating is non-distractible and goal-oriented toward food. The exploratory PET imaging finds higher glucose metabolism in the hypothalamus, right hippocampus and mid brain region and a trend toward higher metabolism in the striatum. Dysregualted ADAR2 protein expression and altered 5HT_2CR splice variants, dopamine and opioid receptor expression in the hypothalamus suggests ADAR2 plays an important role in feeding and reward behaviors of ADAR2 transgenic mice. Dysfunctional reward circuitry is associated with significantly altered mu, D1 and D2 receptors mRNAs in hypothalamus and increased D1 receptor mRNA expression and altered bioamines in striatum of ADAR2 transgenic mice. Significant changes in serotonin and dopamine metabolites in the striatum further suggests a dysfunctional reward system involving both ‘liking’ and ‘wanting’ behaviors, which most likely contributes to the incentive overeating behavior of ADAR2 transgenic mice.

The Val/Val individuals scored significantly higher on the working memory (WM) task than the Met/Val group and the Met/Met group scored lowest. We reported a significant finding that a functional single nucleotide peptide catechol-O-methyltransferase (COMT) rs4680 is associated with WM performance and WM-related brain anatomy (hippocampus) in young healthy Chinese. Directions of the genetic effects on WM performance and hippocampal volumes are both opposite of those found in Caucasian samples (i.e. the Val allele is linked to better WM performance and larger hippocampus volume in Chinese), suggesting an ethnic difference in COMT–hippocampus–WM association.

A QTL region affecting social behaviour in chickens is identified. Candidate genes include AVPR1a and NRCAM.

Exposure to the volatile anesthetic halothane decreases flies' resource-independent local enhancement.

APOE polymorphism has no major influence on brain injuries or neurodevelopment in very preterm/VLBW children.

Carriers of the short rh5-HTTLPR allele evidenced a higher neutrophil-to-lymphocyte ratio in blood than their LL counterparts while in undisturbed housing conditions, indicative of an aroused state even in the absence of disturbance. In addition, S carriers underwent greater inhibition of cellular IL-6 responses to LPS stimulation after rehousing with an unfamiliar monkey. The inhibitory effect of stress remained evident in S-carriers even after adjusting for the number of mononucleocytes in circulation.

http://www.ibngs.org/2013-genes-brain-and-behavior-meeting