Heroin abuse and natural aging exert common influences on immunological cell functioning. This observation led to a recent and untested idea that aging may be accelerated in abusers of heroin. We examined this claim by testing whether heroin use is associated with premature aging at both cellular and brain system levels. A group of abstinent heroin users (n=33) and matched healthy controls (n=30) were recruited and measured on various biological indicators of aging. These measures included peripheral blood telomerase activity, which reflects cellular aging, and both structural and functional measures of brain magnetic resonance imaging. We found that heroin users were characterized by significantly low telomerase activity (0.21 vs 1.78; 88% reduction; t(61)=6.96, P<0.001; 95% confidence interval=1.12–2.02), which interacted with heroin use to affect the structural integrity of gray and white matter of the prefrontal cortex (PFC; AlphaSim corrected P<0.05), a key brain region implicated in aging. Using the PFC location identified from the structural analyses as a ‘seed' region, it was further revealed that telomerase activity interacted with heroin use to impact age-sensitive brain functional networks (AlphaSim corrected P<0.05), which correlated with behavioral performance on executive functioning, memory and attentional control (Pearson correlation, all P<0.05). To our knowledge, this study is the first to attempt a direct integration of peripheral molecular, brain system and behavioral measures in the context of substance abuse. The present finding that heroin abuse is associated with accelerated aging at both cellular and brain system levels is novel and forms a unique contribution to our knowledge in how the biological processes of drug abusers may be disrupted.

Previous studies have suggested that men and women process emotional stimuli differently. In this study, we examined if there would be any consistency in regions of activation in men and women when processing stimuli portraying happy or sad emotions presented in the form of facial expressions, scenes, and words. A blocked design BOLD functional magnetic resonance imaging paradigm was employed to monitor the neural activities of male and female healthy volunteers while they were presented with the experimental stimuli. The imaging data revealed that the right insula and left thalamus were consistently activated for men, but not women, during emotion recognition of all forms of stimuli studied. To further understand the imaging data acquired, we conducted the protocol analysis method to identify the cognitive processes engaged while the men and women were viewing the emotional stimuli and deciding whether they were happy or sad. The findings suggest that men rely on the recall of past emotional experiences to evaluate current emotional experiences. This may explain why the insula, a structure important for self-induced or internally generated recalled emotions, was consistently activated in men while processing emotional stimuli. Our findings suggest possible gender-related neural responses to emotional stimuli. Keywords: emotion; gender; functional magnetic resonance imaging; neuroscience; neuropsychology; emotion recognition It is a common belief that women are more emotional than men. Do men and women, then, process emotional stimuli differently? Sex differences in brain anatomy 1,2 and cognition 3,4 have been increasingly documented. For example, Gur et al 5 observed that women have larger orbital frontal cortices than men and speculated that women have greater tissue volume available for modulating amygdala input leading to gender differences in emotional behavior, particularly aggression. However, studies addressing sex differences in neural activity associated with processing emotional stimuli remain scarce.Kesler/West et al 6 used fMRI to investigate explicit processing of facial emotions including happiness and sadness. They observed that men showed greater left hemispheric activation when observing sad faces than when observing happy faces. No such differences between the emotions in either hemisphere existed among women. Lane et al 7 used PET to study the neural correlates of pleasant and unpleasant emotions, and observed both common and unique components of the neural networks mediating the emotions in healthy women. Canli et al 8 studied sex differences in the neural basis of emotional memories and observed that women had significantly more brain regions than men in which greater activation correlated with both emotional-intensity ratings and better recognition memory for the most emotionally intense picture selected from the International Affective Picture Series (IAPS) 9 and by successful encoding of that experience into long-term memory. In a prior study, Lee et al 10 examined the effect of sex on ...

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