Project No.2231

Primary Supervisor

Dr Eisuke Koya – University of Sussex

Co-Supervisor(s)

Dr Hans Crombag – University of Sussex

Prof Jerome Swinny – University of Portsmouth

Summary

Conditioning processes link signals or ‘cues’ (e.g. smell of food) with food, which guide motivated actions to seek and consume food via retrieval of food memories.

In certain individuals, cue exposure elicits food cravings that contribute to overeating and obesity. Many studies have examined how the brain triggers reactions to cues and promote food seeking and consumption. However, an important and understudied aspect of cue reactivity research is how the brain harnesses anti-craving mechanisms to suppress food seeking and consumption. Interestingly, we have observed in mice that brief exposure to

environmentally enriched (EE) housing, which provides cognitive and physical stimulation through toys and exercise, reduces both cue-triggered food seeking and food consumption. Thus, EE reduces the motivational impact of food cues and food. In our BBSRC-funded studies, we have shown that food cues activate sparse sets of neurons called ‘neuronal ensembles’ in brain areas implicated in reward and motivation, such as the prefrontal cortex and nucleus accumbens (e.g. Ziminski et al. 2017; PMID: 28213443; Brebner et al. 2020; PMID: 3172294). However, little is known about how EE mediates its actions by modulating the neuronal activity patterns within these brain areas upon food cue exposure. Thus, the aim of this project is to reveal the mechanisms behind EE’s action in these brain areas using state-of-the-art in vivo methods, such as fibre photometry and optogenetics and histological methods. With 2 of 3 UK individuals overweight or obese, tackling obesity is a priority area for the UK government. Furthermore, these conditions increase the risks of developing other serious illnesses such as diabetes, and clinical complications from COVID-19 and burden the NHS. Hence, understanding the mechanisms that suppress food seeking and food consumption will have significant economic and societal impact.