Altered orbitofrontal activity and dorsal striatal connectivity during emotion processing in dependent marijuana users after 28 days of abstinence

Abstract

Together, the present findings provide the first evidence for persisting emotion processing alterations in dependent marijuana users. Alterations might reflect long-term neural adaptations as a consequence of chronic marijuana use or predisposing risk factors for the development of marijuana dependence.

Aberrant structural–functional coupling in adult cannabis users

“…One interpretation for the study findings could be that increased SC-FC coupling in users may indicate that functional interaction through the hippocampus was influenced by CB use and was consequently more likely to depend on the underlying structural connections indicating less dynamic brain function, as similar to a previous study on schizophrenia (Van den Heuvel et al, 2013 pathways (e.g., the striatum) (Herkenham, Lynn, de Costa, & Richfield, 1991). Further, CB use reduces the level of dopamine in the striatum, reducing dopamine synthesis in the dorsal striatum including the caudate (Bloomfield, Ashok, Volkow, & Howes, 2016 (Filbey & Dunlop, 2014) and in the dorsal striatum including the caudate during cognitive tasks (Ma et al, 2018;Zimmermann et al, 2018), suggesting compensatory processes. Our findings further suggest that current CB users have altered SC-FC coupling in the hippocampus and caudate.…”

Shifted balance of dorsal versus ventral striatal communication with frontal reward and regulatory regions in cannabis‐dependent males

“…Cannabis use patterns and the use of other drugs were assessed using corresponding modules of a structured interview that has been used in previous studies of our group (e.g., Becker et al, 2015;Becker, Wagner, Gouzoulis-Mayfrank, Spuentrup, & Daumann, 2010;Zimmermann, Yao, et al, 2017). Cannabis use patterns and the use of other drugs were assessed using corresponding modules of a structured interview that has been used in previous studies of our group (e.g., Becker et al, 2015;Becker, Wagner, Gouzoulis-Mayfrank, Spuentrup, & Daumann, 2010;Zimmermann, Yao, et al, 2017).…”

“…Resting state fMRI functional connectivity (rsfMRI-FC) approaches allow a more holistic assessment of functional alterations in the absence of task or contextual modulation. Two recent studies applied rsfMRI-FC to determine lasting disruptions in the frontostriatal functional circuitries in cannabis dependence (Blanco-Hinojo et al, 2017;Zimmermann, Yao, et al, 2017). Two recent studies applied rsfMRI-FC to determine lasting disruptions in the frontostriatal functional circuitries in cannabis dependence (Blanco-Hinojo et al, 2017;Zimmermann, Yao, et al, 2017).…”

“…Moreover, these approaches have a high sensitivity for transient and lasting striatal alterations on the subregion-specific network level (Di Martino et al, 2008;Di Martino et al, 2011). However, findings were limited by the confirmatory nature of the rsfMRI-FC analysis (Zimmermann, Yao, et al, 2017) or the use of literature-based striatal seed regions (Blanco-Hinojo et al, 2017) that have a high sensitivity to capture subregion specific functional networks in healthy subjects (Di Martino et al, 2008) but might not be sensitive to the specific alterations related to cannabis dependence. However, findings were limited by the confirmatory nature of the rsfMRI-FC analysis (Zimmermann, Yao, et al, 2017) or the use of literature-based striatal seed regions (Blanco-Hinojo et al, 2017) that have a high sensitivity to capture subregion specific functional networks in healthy subjects (Di Martino et al, 2008) but might not be sensitive to the specific alterations related to cannabis dependence.…”

“…Two recent studies applied rsfMRI-FC to determine lasting disruptions in the frontostriatal functional circuitries in cannabis dependence (Blanco-Hinojo et al, 2017;Zimmermann, Yao, et al, 2017). However, findings were limited by the confirmatory nature of the rsfMRI-FC analysis (Zimmermann, Yao, et al, 2017) or the use of literature-based striatal seed regions (Blanco-Hinojo et al, 2017) that have a high sensitivity to capture subregion specific functional networks in healthy subjects (Di Martino et al, 2008) but might not be sensitive to the specific alterations related to cannabis dependence. Despite supporting evidence for a striatal shift in response to masked drug cues in cannabis dependence , the ventral to dorsal shift has not been explicitly examined in the absence of external stimulation.…”