Posted by Annapaola Prestia Laboratory of Epidemiology Neuroimaging and Telemedicine, IRCCS Centro San Giovanni di Dio FBF, The National Centre for Research and Care of Alzheimer’s and Mental Diseases, Brescia, Italy. October 2010

Neuroanatomical differences between men and women, as well as sex differences in behaviours and cognitive performances have been well demonstrated. However, to date, little is known about the differences in aging and sex of the organizational patterns of anatomical connectivity. The present study aimed to explore age and sex effects on the anatomical connectivity patterns of 95 normal subjects ranging in age from 19 to 85 years by diffusion magnetic resonance imaging tractography. Researchers focus on the network efficiency that characterizes how well the information spread within the cerebral cortex. Particularly, they hypothesized that the cortical network efficiency as well as the regional efficiency of selective cortical regions were different in aging and sex. Results revealed a reduction in overall cortical connectivity with age. In addition, women showed greater overall cortical connectivity and the underlying organization of their cortical networks was more efficient, both locally and globally. There were also distributed regional differences in efficiency between sexes. These results provide new insights into the substrates that underlie behavioural and cognitive differences in aging and sex.