Neurobiology of Aging
August 1, 2008
Fabio Sambataro, Vishnu P. Murty, Joseph H. Callicott et al.
534 citations
Normal aging reduces the ability to suppress low-frequency oscillations and decreases functional connectivity within the default mode network (DMN) during a working memory task. Older adults showed weaker coupling between the posterior cingulate and medial prefrontal cortex, and this coupling strength correlated positively with performance. The posterior cingulate was also negatively coupled with task-related regions like the dorsolateral prefrontal cortex and cingulate. These changes may reflect a deficit in cognitive control that impairs resource allocation to the task.
Addiction Biology
November 22, 2021
Dusan Hirjak, Mike M. Schmitgen, Florian Werler et al.
33 citations
Heavy cannabis use (HCU) is linked to changes in both brain structure and function, even in individuals without a cannabis-use disorder or other major mental illnesses. This study used multimodal MRI to examine grey matter volume and intrinsic neural activity in 24 heavy users and 16 controls. Two distinct brain component patterns differed between groups: one involving the cerebellum, temporal, and thalamic regions (structural), and another involving frontal and parietal regions (functional). These patterns correlated with specific cannabis-use behaviors. Additionally, the structural changes were associated with the serotonergic system, while functional changes were linked to serotonergic, dopaminergic, and μ-opioid receptor systems, offering new insights into the neural mechanisms of heavy cannabis use.
Journal of affective disorders
February 1, 2025
Farzaneh Ramezani, Peyman Mardani, Fatemeh Nemati et al.
4 citations
Ketamine alters brain activity in people with major depressive disorder, particularly in the anterior cingulate cortex, dorsolateral prefrontal cortex, and amygdala. Most reviewed studies found that these changes in brain activity correlate with improvements in depressive symptoms, involving the prefrontal cortex, ACC, and cortico-cerebellar circuits. The review notes a lack of longitudinal data on lasting effects and a small number of studies. It calls for more research on ketamine's mechanisms, long-term impact, dose-response optimization, and comparisons with other fast-acting antidepressants.
Journal of affective disorders
July 15, 2026
Iman Kiani, Giulia Cattarinussi, Fabio Sambataro et al.
A systematic review of fifteen neuroimaging studies identifies potential brain-based markers that could predict which patients with major depressive disorder will respond to ketamine. The anterior cingulate cortex and amygdala, along with their connections to other brain regions, frequently predicted better response. Higher fractional anisotropy in the cingulum, larger hippocampus volume, and a higher Glx/glutamate ratio in the dorsomedial prefrontal cortex also correlated with response. Task-based imaging showed that anterior cingulate cortex activity predicted antidepressant response. The review notes limitations due to differences in assessments, follow-up times, ketamine doses, and imaging methods across studies.