A Pontine Region is a Neural Correlate of the Human Affective Processing Network

The in vivo neural activity of the pons during the perception of affective stimuli has not been studied despite the strong implications of its role in affective processing. To examine the activity of the pons during the viewing of affective stimuli, and to verify its functional and structural connectivity with other affective neural correlates, a multimodal magnetic resonance imaging methodology was employed in this study. We observed the in vivo activity of the pons when viewing affective stimuli. Furthermore, small-world connectivity indicated that the functional connectivity (FC) between the pons and the cortico-limbic affective regions was meaningful, with the coefficient λ being positively associated with self-reported emotional reactivity. The FC between the pons and the cortico-limbic-striatal areas was related to self-reported negative affect. Corroborating this finding was the observation that the tract passing through the pons and the left hippocampus was negatively related to self-reported positive affect and positively correlated with emotional reactivity. Our findings support the framework that the pons works conjunctively with the distributed cortico-limbic-striatal systems in shaping individuals' affective states and reactivity. Our work paves the path for future research on the contribution of the pons to the precipitation and maintenance of affective disorders.published_or_final_versio

Imaging and neuropsychological correlates of white matter lesions in different subtypes of Mild Cognitive Impairment: A systematic review

BACKGROUND:White matter lesions (WML) are prevalent in older adults. The association between WML and cognition in different subtypes of Mild Cognitive Impairment (MCI) is inconsistent in the literature.OBJECTVES:We aim to provide a systematic review on the impact of WML in different subtypes of MCI, and discuss the recent findings on white matter plasticity.METHODS:We reviewed peer-reviewed articles from January 2011 to August 2016 and identified 12 studies investigating the association between WML and subtypes of MCI with both neuroimaging and cognitive measures.RESULTS:Our review shows that 1) WM abnormality was identified between different subtypes of MCI and healthy controls on diffusion imaging; 2) neither visual ratings of WML nor its volumetry differentiate different subtypes of MCI or its prognosis to dementia; and 3) cognitive correlates of WML were evident in the Amnestic-type MCI in the domains of memory, language, psychomotor speed, attention and executive functions.CONCLUSION:Cognitive reserve and the plasticity of white matter may modulate the impact of WML on the manifestation of the neurodegenerative disease. Further research is needed to study the plasticity of white matter in the MCI population to evaluate its potential clinical application

Pons to Posterior Cingulate Functional Projections Predict Affective Processing Changes in the Elderly Following Eight Weeks of Meditation Training

Evidence indicates meditation facilitates affective regulation and reduces negative affect. It also influences resting-state functional connectivity between affective networks and the posterior cingulate (PCC)/precuneus, regions critically implicated in self-referential processing. However, no longitudinal study employing active control group has examined the effect of meditation training on affective processing, PCC/precuneus connectivity, and their association. Here, we report that eight-week meditation, but not relaxation, training ‘neutralized’ affective processing of positive and negative stimuli in healthy elderly participants. Additionally, meditation versus relaxation training increased the positive connectivity between the PCC/precuneus and the pons, the direction of which was largely directed from the pons to the PCC/precuneus, as revealed by dynamic causal modeling. Further, changes in connectivity between the PCC/precuneus and pons predicted changes in affective processing after meditation training. These findings indicate meditation promotes self-referential affective regulation based on increased regulatory influence of the pons on PCC/precuneus, which new affective-processing strategy is employed across both resting state and when evaluating affective stimuli. Such insights have clinical implications on interventions on elderly individuals with affective disorders