Details

Autor(en) / Beteiligte

• Pardo-Garcia, Thibaut R.
• Gu, Kathleen
• Woerner, Riley K.R.
• Dus, Monica

Titel

Food memory circuits regulate eating and energy balance

Ist Teil von

• Current biology, 2023-01, Vol.33 (2), p.215-227.e3

Ort / Verlag

England: Elsevier Inc

Erscheinungsjahr

2023

Quelle

MEDLINE

Beschreibungen/Notizen

• In mammals, learning circuits play an essential role in energy balance by creating associations between sensory cues and the rewarding qualities of food. This process is altered by diet-induced obesity, but the causes and mechanisms are poorly understood. Here, we exploited the relative simplicity and wealth of knowledge about the D. melanogaster reinforcement learning network, the mushroom body, in order to study the relationship between the dietary environment, dopamine-induced plasticity, and food associations. We show flies that are fed a high-sugar diet cannot make associations between sensory cues and the rewarding properties of sugar. This deficit was caused by diet exposure, not fat accumulation, and specifically by lower dopamine-induced plasticity onto mushroom body output neurons (MBONs) during learning. Importantly, food memories dynamically tune the output of MBONs during eating, which instead remains fixed in sugar-diet animals. Interestingly, manipulating the activity of MBONs influenced eating and fat mass, depending on the diet. Altogether, this work advances our fundamental understanding of the mechanisms, causes, and consequences of the dietary environment on reinforcement learning and ingestive behavior. [Display omitted] •Sugar consumption impairs food associations independently of obesity•Diet-induced changes in DA-induced plasticity cause learning deficits•Food associations change the responses of learning circuits during eating•The activity of associative learning circuits affects eating and energy balance Pardo Garcia et al. show that a high-sugar diet disrupts the creation of food memories by decreasing the reinforcing power of dopamine signals onto the mushroom body output neurons (MBONs). In the absence of learning signals, the activity of MBONs is static during eating, affecting intake and energy homeostasis.