Gray matter density negatively correlates with duration of heroin use in young lifetime heroin-dependent individuals

Resting-state Abnormalities in Heroin-dependent Individuals

“…Moreover, few studies associated structural reductions with rsFC impairments (Liu et al, 2009b;Yuan et al, 2009Yuan et al, , 2010aYuan et al, , 2010cMa et al, 2010) despite the fact that their causal relationship remains unknown.…”

“…Recently the scientific community has witnessed an explosion in the study of functional connectivity modulations (Polunina et al, 2007;Ma et al, 2010Ma et al, , 2011Wang et al, 2010Wang et al, , 2013Yuan et al, 2010a;Xie et al, 2011;Zhang et al, 2011;Moreno-López et al, 2012), structural deficits (Liu et al, 2008(Liu et al, , 2009aYuan et al, 2009Yuan et al, , 2010bBora et al, 2010;Wang et al, 2012;Qiu et al, 2011Qiu et al, , 2013Wang et al, 2011;Lin et al, 2012;Denier et al, 2013a;Zhang et al, 2013;Li et al, 2013aLi et al, , 2013c and changes in topological properties (Liu et al, 2009bYuan et al, 2010c;Jiang et al, 2013) in heroin-dependent individuals at rest.Resting-state is defined as a state that is characterized by the absence of a specific goal-oriented activity or alternatively as a task-free state where the subjects rest quietly awake with their eyes closed, as it has been proposed by Raichle et al (2001). Nevertheless, a more complex baseline or control state such as visual fixation of a cross hair on a monitor or alternatively passive viewing of a stimulus (Greicius et al, 2003;Fox et al, 2005;Fransson, 2006;Fair et al, 2008;Fransson and Marrelec, 2008) is more frequently used.…”

“…This finding contradicts to the findings ofWang et al 2010 who reported significant functional connectivity between ventral aspects of anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC)/ medial PFC. Finally, Yuan et al (2010) reported that a distributed brain network that is involved in drug addiction and consists of ACC, amygdala, OFC, DLPFC, NAc, MPFC and insula according to the existing literature (Wilson et al, 2004;Lee et al, 2005;Fu et al, 2008;Yuan et al, 2009). Another study (Yuan et al, 2010b) of the same research group revealed a reduced rsFC between the right DLPFC and the left inferior parietal lobe (IPL).…”

“…FA and axial diffusivity reduction together with increased radial diffusivity, in the cerebellum's anterior vermis might be linked to demyelinationor fiber reconstruction and axonal injury (Lin et al, 2012). Finally, GM deficits have been reported in this brain area, suggesting the dysfunction of cerebellum (Yuan et al, 2009). …”

“…On the other hand, postmortem tracers have no practical value due to their glacial pace (Sparks et al, 2000). But, researchers are now equipped withmodern imaging technologies such as structural magnetic resonance (Liu et al, 2009a;Wang et al, 2012;Li et al, 2013a) or fMRI associated with voxel-based morphometry approach (Yuan et al, 2010b;Qiu et al, 2013), regional homogeneity tool , pharmacological MRI (phMRI) (Denier et al, 2013a) or fMRI combined to a pulsed arterial spin labeling (Denier et al, 2013b) and quantitative diffusion tensor imaging (Liu et al, 2008;Bora et al, 2010;Wang et al, 2011;Lin et al, 2012;Zhang et al, 2013).Numerous imaging studies have shown structural deficits that are associated both gray (Liu et al, 2009a;Yuan et al, 2009Yuan et al, , 2010bWang et al, 2012;Denier et al, 2013a;Qiu et al, 2013) and white matter (Liu et al, 2008;Bora et al, 2010;Wang et al, 2011;Lin et al, 2012;Li et al, 2013c;Zhang et al, 2013) reductions, perfusion's decrement (Denier et al, 2013a(Denier et al, , 2013b, diminished homogeneity and abnormal cortical thickness (Li et al, 2013a). Moreover, few studies associated structural reductions with rsFC impairments (Liu et al, 2009b;Yuan et al, 2009Yuan et al, , 2010aYuan et al, , 2010cMa et al, 2010) despite the fact that their causal relationship remains unknown.…”