Drug addiction is a global issue with significant social and health-related impacts, and conventional treatments ften fall short in providing long-term recovery. Bright light therapy (BLT), traditionally utilized for sessional effective disorder, might have potential as a non-invasive method for treating addiction due to its modulation of brain regions involved in reward and mood, particularly the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc). A recently discovered pathway includes intrinsically photosensitive retinal ganglion cells (ipRGCs) that project to the perihabenular nucleus (PHb) that innervates the mPFC and NAc. Via this pathway light can potentially modulate activity in the mPFC and NAc and effect addiction. In my research, I explore light’s effects on addiction by investigating its influence on neuronal activity in the mPFC and NAc in mice, the effect of light on addiction-like behaviors in mice, and its potential to treat nicotine addiction in humans. In my research I will (1) examine light’s impact on neuronal responses in the mPFC and NAc, employing chemogenetic and optogenetic techniques to determine the involvement of the ipRGCs-PHb-mPFC/NAc pathway; (2) assesses the effect of BLT on cocaine addiction-like behaviors in mice using the conditioned place preference paradigm, highlighting light’s potential to alter reward-seeking behaviors through mPFC and NAc modulation. (3) translates these findings into a clinical setting, testing BLT’s efficacy in reducing nicotine dependence through an 8-week trial and assessing brain function via fMRI. By bridging preclinical and clinical research, this study aims to establish BLT as a viable, non-invasive treatment for addiction, with broader implications for mood and reward-related disorders.

Supervisor: Dr. Shai Sabbah