Page 18 - ITPS-7-4

INNOSC Theranostics and
Pharmacological Sciences Neurobiology of gaming disorder

between the right dorsal putamen and the right middle cue-related cravings before scanning showed a negative
occipital gyrus (MOG) over time, when compared to correlation with GD severity measured by DSM-5 scores
healthy controls. The mPFC is a region associated with and the left-hemispheric modulatory effect from the ACC
self-regulation and is responsible for maintaining goal- to the lentiform.
directed behaviors over a long period of time for a larger A study was conducted to examine glucose metabolism
reward. The MOG is a region responsible for visuospatial and metabolic connectivity using positron emission
processing and is associated with the sensorimotor tomography (PET) in individuals with GD. The results
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network. These findings suggest that GD is associated with showed hypometabolism in the ACC in the GD group
a weakening of the PFC, whereas the sensorimotor circuit, compared to both healthy controls and those with alcohol
which is connected to habit formation, strengthens. use disorder (AUD). In addition, a negative correlation
In addition, previous cross-sectional studies have also was found between glucose metabolism in the ACC and
reported differences in the rsFC of fronto-striatal circuits the duration of gaming use in the GD group. Significant
between individuals with GD and controls. Yuan et al. reductions in metabolic connectivity were observed
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demonstrated abnormal rsFC within the ventral and dorsal between prefrontal and limbic regions, including the
striatum networks. Specifically, they found a decrease striatum, in both the GD and AUD groups compared to
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in the strength of rsFC between the dorsolateral PFC the healthy controls. Another PET study was conducted
(DLPFC) and caudate, as well as between the orbitofrontal to assess D2R availability of the striatum and glucose
cortex (OFC) and NA. Jin et al. observed more extensive metabolism in individuals with GD under the game task
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abnormal prefrontal-striatal circuits in individuals with state. The study showed that the GD group had reduced
GD, including the anterior cingulate cortex (ACC)–striatal, D2R availability in the striatum. In addition, the level of
OFC–striatal, and DLPFC–striatal circuits. Specifically, the D2R in the striatum was significantly associated with
study found negative correlations between the rsFC of the decreased glucose metabolism in the OFC, indicating
right ACC–left putamen, left OFC–left caudate, and left dysregulation of the prefrontal-striatal circuit.
DLPFC–left pallidum and YIAT scores in the GD group. 4. Impairments in executive control
A previous review on addiction proposed that unbalanced
prefrontal-striatal circuits may reflect observable behaviors Impairments in executive function, such as reduced
that characterize the addiction, such as impaired self- response inhibition, increased impulsivity, and impaired
control and compulsive drug consumption. 30 decision-making, are closely associated with the pursuit of
compulsive addictive behaviors. These impairments play a
After evaluating the rsFC during a stimulus-response crucial role in the mechanism of addiction, contributing to
association learning task in GD, Kim and Kang found its maintenance and relapse. 15
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that, for monetary reward, the rsFC of the ventromedial
PFC (vmPFC) with the left caudate and various prefrontal Several studies have reported structural and functional
regions, such as the ventrolateral PFC and dorsal ACC changes in brain areas, including the DLPFC, OFC, ACC,
with the ventral striatum, was weaker in the GD group and insula, suggesting a decline in executive function
relative to controls. In addition, the vmPFC rsFC with in the context of GD. Individuals with GD exhibited a
the right NA was elevated. Dong et al. investigated the significant decrease in GM volume or cortical thickness
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directional functional connectivity between the ACC in the DLPFC, 21,29 ventrolateral PFC, OFC, 29,35,36 ACC, 29,34
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and the lentiform nucleus (putamen and globus pallidus insula, and the supplementary motor area 29,34,35 compared
as part of the basal ganglia) during a cue-craving task in to healthy controls or RGU. The left DLPFC’s GM density
individuals with GD. The study found enhanced brain and the ventrolateral PFC’s GM volume were associated
responses in the lentiform nucleus, which may suggest with lifetime usage of Internet gaming, 21,34 whereas the GM
reward sensitivity or cravings in response to specific cues. volume in the OFC and insula was negatively correlated
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In addition, the lentiform nucleus typically exhibits greater with the YIAT scores in the GD group. Another study,
activity in GD subjects relative to non-GD subjects when which compared GM density among three groups – non-
exposed to gaming-related cues. The results demonstrated gamer, RGU, and GD group – indicated a marked decrease
that individuals with GD showed reduced ACC-to- in the DLPFC in the GD group compared to the other two
lentiform and lentiform-to-ACC connectivity relative to groups, and this density was associated with lifetime usage
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RGU. Furthermore, when presented with gaming cues, GD of Internet gaming.
subjects showed a trend toward decreased left-hemispheric Regarding white matter integrity, reduced FA has been
modulatory effects in ACC-to-lentiform connectivity identified in the bilateral frontal lobe, corpus callosum,
compared to RGU. The study also found that self-reported and external capsule in individuals with GD compared

Volume 7 Issue 4 (2024) 4 doi: 10.36922/itps.3326