Cuprizone-induced demyelination in mice: age-related vulner-ability and exploratory behavior deficit

Schizophrenia is a mental disease that mainly affects young individuals （15 to 35 years old） but its etiology remains largely undefined. Recently, accumulating evidence indicated that demyelination and/or dysfunction of oligodendrocytes is an important feature of its pathogenesis. We hypothesized that the vulnerability of young individuals to demyelination may contribute to the onset of schizophrenia. In the present study, three different age cohorts of mice, i.e. juvenile （3 weeks）, young-adult （6 weeks） and middle-aged （8 months）, were subjected to a 6-week diet containing 0.2% cuprizone （CPZ） to create an animal model of acute demyelination. Then, age-related vulnerability to CPZ-induced demyelination, behavioral outcomes, and myelination-related molecular biological changes were assessed. We demonstrated： （1） CPZ treatment led to more severe demyelination in juvenile and young-adult mice than in middle-aged mice in the corpus callosum, a region closely associated with the pathophysiology of schizophrenia; （2） the higher levels of demyelination in juvenile and young-adult mice were correlated with a greater reduction of myelin basic protein, more loss of CC-1- positive mature oligodendrocytes, and higher levels of astrocyte activation; and （3） CPZ treatment resulted in a more prominent exploratory behavior deficit in juvenile and young-adult mice than in middle-aged mice. Together, our data demonstrate an age-relatedvulnerability to demyelination with a concurrent behavioral deficit, providing supporting evidence for better understanding the susceptibility of the young to the onset of schizophrenia.

Studies of cocoa tea, a wild tea tree containing theobromine

Camellia ptilophylla Chang is a wild tea tree containing theobromine and is caffeine-free.Lots of researches have been conducted for its domestication since it was discovered to contain theobromine in its shoots.First,its pharmacological and physiological effects have been studied,demonstrating that it can be used as a new resource of tea as daily and healthy beverage.Cocoa tea differs from traditional tea in that it does not excite the nervous system.Second,various ways of propagation have been investigated,and sexless cutting has been the method adopted currently.Third,through selection and breeding,plantation of cocoa tea can be set up to cultivate new varieties,and cocoa tea of different flavors such as green cocoa tea,oolong cocoa tea,and black cocoa tea can be processed.Thus,cocoa tea will become a choice in the tea market.