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Molecular and functional imaging of internet addiction.

Zhu Y, Zhang H, Tian M - Biomed Res Int (2015)

Bottom Line: MRI studies demonstrate that structural changes in frontal cortex are associated with functional abnormalities in Internet addicted subjects.Nuclear imaging findings indicate that IA is associated with dysfunction of the brain dopaminergic systems.Further investigations are needed to determine specific changes in the Internet addictive brain, as well as their implications for behavior and cognition.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, Zhejiang 310009, China ; Zhejiang University Medical PET Center, Hangzhou 310009, China ; Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou 310009, China ; Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou 310009, China.

ABSTRACT
Maladaptive use of the Internet results in Internet addiction (IA), which is associated with various negative consequences. Molecular and functional imaging techniques have been increasingly used for analysis of neurobiological changes and neurochemical correlates of IA. This review summarizes molecular and functional imaging findings on neurobiological mechanisms of IA, focusing on magnetic resonance imaging (MRI) and nuclear imaging modalities including positron emission tomography (PET) and single photon emission computed tomography (SPECT). MRI studies demonstrate that structural changes in frontal cortex are associated with functional abnormalities in Internet addicted subjects. Nuclear imaging findings indicate that IA is associated with dysfunction of the brain dopaminergic systems. Abnormal dopamine regulation of the prefrontal cortex (PFC) could underlie the enhanced motivational value and uncontrolled behavior over Internet overuse in addicted subjects. Further investigations are needed to determine specific changes in the Internet addictive brain, as well as their implications for behavior and cognition.

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11C-NMSP PET imaging of dopamine D2 receptor availability in IGD subjects. (a) In the resting state, low level of 11C-NMSP binding was found in the right inferior temporal gyrus in the IGD subjects compared to controls (yellow color) (P < 0.001 uncorrected, k = 100). (b) In the game task state, 11C-NMSP binding in the putamen was significantly lower in the IGD group than the control group, especially in the right side (yellow color) (P < 0.001 uncorrected, k = 100). (c) Both right (P = 0.024, r = −0.775) and left putamen 11C-NMSP binding potential (P = 0.034, r = −0.744) correlated negatively with the Young score in the IGD subjects. (d) The left OFC to the cerebellum ratio of 11C-NMSP binding correlated negatively with the duration of internet overuse (P = 0.034, r = −0.745) [69].
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fig2: 11C-NMSP PET imaging of dopamine D2 receptor availability in IGD subjects. (a) In the resting state, low level of 11C-NMSP binding was found in the right inferior temporal gyrus in the IGD subjects compared to controls (yellow color) (P < 0.001 uncorrected, k = 100). (b) In the game task state, 11C-NMSP binding in the putamen was significantly lower in the IGD group than the control group, especially in the right side (yellow color) (P < 0.001 uncorrected, k = 100). (c) Both right (P = 0.024, r = −0.775) and left putamen 11C-NMSP binding potential (P = 0.034, r = −0.744) correlated negatively with the Young score in the IGD subjects. (d) The left OFC to the cerebellum ratio of 11C-NMSP binding correlated negatively with the duration of internet overuse (P = 0.034, r = −0.745) [69].

Mentions: In a more in-depth study, our group investigated both dopamine D2 receptor and glucose metabolism in the same individuals using PET with 11C-N-methylspiperone (11C-NMSP) and 18F-FDG, in both states of resting and internet gaming task [69]. A significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems in IGD subjects. In the resting state, low level of 11C-NMSP binding was found in the right inferior temporal gyrus in the IGD subjects compared to normal controls (Figure 2(a)). After Internet gaming task, 11C-NMSP binding potential in the striatum was significantly lower in IGD subjects compared with controls, indicating reduced level of dopamine D2 receptor (Figure 2(b)). Dysregulation of dopamine D2 receptor was correlated to years of Internet overuse (Figure 2(d)). Importantly, in IGD subjects, low level of dopamine D2 receptor in the striatum was correlated with decreased glucose metabolism in the OFC. These results suggest that dopamine D2 receptor mediated dysregulation of the OFC could underlie a mechanism for loss of control and compulsive behavior in IGD subjects.


Molecular and functional imaging of internet addiction.

Zhu Y, Zhang H, Tian M - Biomed Res Int (2015)

11C-NMSP PET imaging of dopamine D2 receptor availability in IGD subjects. (a) In the resting state, low level of 11C-NMSP binding was found in the right inferior temporal gyrus in the IGD subjects compared to controls (yellow color) (P < 0.001 uncorrected, k = 100). (b) In the game task state, 11C-NMSP binding in the putamen was significantly lower in the IGD group than the control group, especially in the right side (yellow color) (P < 0.001 uncorrected, k = 100). (c) Both right (P = 0.024, r = −0.775) and left putamen 11C-NMSP binding potential (P = 0.034, r = −0.744) correlated negatively with the Young score in the IGD subjects. (d) The left OFC to the cerebellum ratio of 11C-NMSP binding correlated negatively with the duration of internet overuse (P = 0.034, r = −0.745) [69].
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4388011&req=5

fig2: 11C-NMSP PET imaging of dopamine D2 receptor availability in IGD subjects. (a) In the resting state, low level of 11C-NMSP binding was found in the right inferior temporal gyrus in the IGD subjects compared to controls (yellow color) (P < 0.001 uncorrected, k = 100). (b) In the game task state, 11C-NMSP binding in the putamen was significantly lower in the IGD group than the control group, especially in the right side (yellow color) (P < 0.001 uncorrected, k = 100). (c) Both right (P = 0.024, r = −0.775) and left putamen 11C-NMSP binding potential (P = 0.034, r = −0.744) correlated negatively with the Young score in the IGD subjects. (d) The left OFC to the cerebellum ratio of 11C-NMSP binding correlated negatively with the duration of internet overuse (P = 0.034, r = −0.745) [69].
Mentions: In a more in-depth study, our group investigated both dopamine D2 receptor and glucose metabolism in the same individuals using PET with 11C-N-methylspiperone (11C-NMSP) and 18F-FDG, in both states of resting and internet gaming task [69]. A significant decrease in glucose metabolism was observed in the prefrontal, temporal, and limbic systems in IGD subjects. In the resting state, low level of 11C-NMSP binding was found in the right inferior temporal gyrus in the IGD subjects compared to normal controls (Figure 2(a)). After Internet gaming task, 11C-NMSP binding potential in the striatum was significantly lower in IGD subjects compared with controls, indicating reduced level of dopamine D2 receptor (Figure 2(b)). Dysregulation of dopamine D2 receptor was correlated to years of Internet overuse (Figure 2(d)). Importantly, in IGD subjects, low level of dopamine D2 receptor in the striatum was correlated with decreased glucose metabolism in the OFC. These results suggest that dopamine D2 receptor mediated dysregulation of the OFC could underlie a mechanism for loss of control and compulsive behavior in IGD subjects.

Bottom Line: MRI studies demonstrate that structural changes in frontal cortex are associated with functional abnormalities in Internet addicted subjects.Nuclear imaging findings indicate that IA is associated with dysfunction of the brain dopaminergic systems.Further investigations are needed to determine specific changes in the Internet addictive brain, as well as their implications for behavior and cognition.

View Article: PubMed Central - PubMed

Affiliation: Department of Nuclear Medicine, The Second Hospital of Zhejiang University School of Medicine, 88 Jiefang Road, Hangzhou, Zhejiang 310009, China ; Zhejiang University Medical PET Center, Hangzhou 310009, China ; Institute of Nuclear Medicine and Molecular Imaging, Zhejiang University, Hangzhou 310009, China ; Key Laboratory of Medical Molecular Imaging of Zhejiang Province, Hangzhou 310009, China.

ABSTRACT
Maladaptive use of the Internet results in Internet addiction (IA), which is associated with various negative consequences. Molecular and functional imaging techniques have been increasingly used for analysis of neurobiological changes and neurochemical correlates of IA. This review summarizes molecular and functional imaging findings on neurobiological mechanisms of IA, focusing on magnetic resonance imaging (MRI) and nuclear imaging modalities including positron emission tomography (PET) and single photon emission computed tomography (SPECT). MRI studies demonstrate that structural changes in frontal cortex are associated with functional abnormalities in Internet addicted subjects. Nuclear imaging findings indicate that IA is associated with dysfunction of the brain dopaminergic systems. Abnormal dopamine regulation of the prefrontal cortex (PFC) could underlie the enhanced motivational value and uncontrolled behavior over Internet overuse in addicted subjects. Further investigations are needed to determine specific changes in the Internet addictive brain, as well as their implications for behavior and cognition.

Show MeSH
Related in: MedlinePlus