Severity of dependence modulates smokers’ functional connectivity in the reward circuit: a preliminary study

Abstract

Our results indicate a dysfunction of the reward circuit in nicotine-dependent individuals. Moreover, our study improves the understanding of the neuroplastic changes that occur during the development of nicotine dependence.

Effect of smoking on resting‐state functional connectivity in smokers: An fMRI study

“…The result may suggest the key role of tobacco dependence in smokers’ insula‐based rsFC. In the reward circuit, a positive correlation between the inter‐hippocampus rsFC and FTND was detected among all smokers in resting state . Both the reward circuit and insula play important roles in tobacco dependence.…”

“…Previous research has explored the changes of rsFC caused by smoking in ventral and dorsal striatum, frontostriatal region, prefrontal and limbic regions, insula and parahippocampus . Widespread rsFC attenuation was observed in the reward circuit of smokers compared with non‐smokers . In young smokers, reduced rsFC was found between caudate and dorsolateral prefrontal cortex and orbitofrontal cortex …”

Altered spontaneous brain activity in chronic smokers revealed by fractional ramplitude of low-frequency fluctuation analysis: a preliminary study

“…However, individuals with shorter smoking history showed weaker fALFF in the left precuneus and right ITG/IOG, whereas those with longer smoking history showed stronger fALFF which was closer to the fALFF value of the nonsmokers. Similar resting-state functional connectivity (rsFC) study showed widespread rsFC attenuation in the reward circuit in smokers and the rsFC was positively correlated with dependence severity 33 . Moreover, microstructural studies found that the generally higher fractional anisotropy (FA) seen in smokers may reflect an increase in FA that follows the initiation of smoking, but prolonged smoking appears to reverse this effect with a progressive decline in FA with increasing pack-years of smoking 34, 35 .…”

“…Several functional brain imaging studies reported that occipital areas were activated following smoking or nicotine exposure during visual task performance 31, 32 . Activated occipital areas have been regarded as neural correlates of nicotine-induced attention increase 32, 33 .…”

Quantic Analysis of the Effect of Nicotine on Neurotransmitters

“…NIC modifies the release of NT and their functions. [10,[13][14] NT is a chemical released from a nerve ending. The transmission of a neuron depends on the action of specific NT on specific receptors.…”