RESUMEN
BACKGROUND: Animal behavior is governed by the activity of interconnected brain circuits. Comprehensive brain wiring maps are thus needed in order to formulate hypotheses about information flow and also to guide genetic manipulations aimed at understanding how genes and circuits orchestrate complex behaviors. RESULTS: To assemble this map, we deconstructed the adult Drosophila brain into approximately 16,000 single neurons and reconstructed them into a common standardized framework to produce a virtual fly brain. We have constructed a mesoscopic map and found that it consists of 41 local processing units (LPUs), six hubs, and 58 tracts covering the whole Drosophila brain. Despite individual local variation, the architecture of the Drosophila brain shows invariance for both the aggregation of local neurons (LNs) within specific LPUs and for the connectivity of projection neurons (PNs) between the same set of LPUs. An open-access image database, named FlyCircuit, has been constructed for online data archiving, mining, analysis, and three-dimensional visualization of all single neurons, brain-wide LPUs, their wiring diagrams, and neural tracts. CONCLUSION: We found that the Drosophila brain is assembled from families of multiple LPUs and their interconnections. This provides an essential first step in the analysis of information processing within and between neurons in a complete brain.
Asunto(s)
Encéfalo/citología , Drosophila/anatomía & histología , Drosophila/fisiología , Animales , Encéfalo/fisiología , Simulación por Computador , Femenino , Masculino , Modelos Biológicos , Neuronas/citología , Neuronas/fisiologíaRESUMEN
BACKGROUND AND PURPOSE: Chronic liver disease (CLD) is a major cause of death in Taiwanese aborigines. The roles of substance-use habits and hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in the development of CLD are not well understood in this indigenous population. METHODS: A hospital-based, case-control study of 79 consecutive CLD patients and 107 non-CLD controls was performed. Serostatus of hepatitis B surface antigen (HBsAg) and antibodies against hepatitis C virus (anti-HCV) were determined in all subjects. Each subject completed an epidemiologic questionnaire about the risk factors of CLD. RESULTS: Atayal ethnicity, alcohol drinking, cigarette smoking, betel quid chewing, seropositivity of HBsAg and anti-HCV antibodies were associated with a significantly elevated CLD risk. In the combinatory analyses of HBsAg serostatus and substance-use habits, HBsAg-positive substance users had the highest CLD risk, followed by HBsAg-positive non-users, HBsAg-negative users, and HBsAg-negative non-users. Similarly, anti-HCV-positive alcohol drinkers and betel quid chewers had greater CLD risks than other groups. The multivariate-adjusted odds ratios (ORs) for males, Atayal ethnicity and seropositivity of HBsAg and anti-HCV were significantly elevated. There was a biologic gradient in the risk of developing CLD associated with the number of substance-use habits. The multivariate-adjusted ORs were 4.7 (95% confidence interval [CI], 1.3-16.8) and 7.9 (95% CI, 2.1-30.4) for subjects with 1-2 and 3 habits, respectively, compared to subjects with no habit. CONCLUSION: Our data suggest that chronic HBV and HCV infections, alcohol drinking, cigarette smoking, and betel quid chewing play important roles in the development of CLD in Taiwanese aborigines.