9 research outputs found
Genetic variation in human NPY expression affects stress response and emotion
Understanding inter- individual differences in stress response requires the explanation of genetic influences at multiple phenotypic levels, including complex behaviours and the metabolic responses of brain regions to emotional stimuli. Neuropeptide Y ( NPY) is anxiolytic(1,2) and its release is induced by stress(3). NPY is abundantly expressed in regions of the limbic system that are implicated in arousal and in the assignment of emotional valences to stimuli and memories(4-6). Here we show that haplotype- driven NPY expression predicts brain responses to emotional and stress challenges and also inversely correlates with trait anxiety. NPY haplotypes predicted levels of NPY messenger RNA in postmortem brain and lymphoblasts, and levels of plasma NPY. Lower haplotype- driven NPY expression predicted higher emotion- induced activation of the amygdala, as well as diminished resiliency as assessed by pain/ stress- induced activations of endogenous opioid neurotransmission in various brain regions. A single nucleotide polymorphism ( SNP rs16147) located in the promoter region alters NPY expression in vitro and seems to account for more than half of the variation in expression in vivo. These convergent findings are consistent with the function of NPY as an anxiolytic peptide and help to explain inter- individual variation in resiliency to stress, a risk factor for many diseases.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62768/1/nature06858.pd
A Novel Approach toward Polyfulvene: Cationic Polymerization of Enediynes
Enediyne compounds have found limited
applications in polymer science
and material chemistry due to the poor regioselectivity and/or the
step-growth nature in their radical polymerizations. However, the
cationic cyclization of enediynes exhibits a high regioselective 5-exo-dig
mechanism, providing a new strategy for the synthesis of polyfulvene
derivatives. The expected polymers were successfully produced by cationic
polymerization of enediynes induced by CF<sub>3</sub>SO<sub>3</sub>H, and a well-defined conjugated structure was confirmed by NMR,
IR, and UV–vis spectroscopy. GPC analysis shows a relatively
narrow molecular weight distribution, and the molecular weight reaches
up to 62.9 kDa. On the other hand, the structural features of the
obtained polymers and the mechanism of the cationic polymerization
were investigated through kinetic study and MALDI-TOF MS analysis,
which revealed a second-order consumption of enediyne monomer and
the polymerization being probably terminated through intramolecular
abstraction of proton from the neighboring group