Research on obesity:
Food seeking is a physiological appetitive behaviour that involves learning of food-predicting cues and contexts, the valuation of how rewarding the food is, effortful behavior and cost-benefit decision-making. Different neural circuits govern these processes and the strength of activity within these circuits depends on the internal state (eg. satiety, stress) of the individual. These processes can also be perturbed by external factors, such as an environment of rich in highly palatable energy dense foods or drugs of abuse. In this line of research, we aim to understand how neural circuits in the ventral tegmental area (VTA) or the orbitofrontal cortex are altered with short or long term obesogenic diets. Dopamine neurons of the VTA encode motivationally relevant information to help guide reward seeking. The laboratory has made exciting discoveries on how plasticity within the mesolimbic dopamine circuit is modulated by satiety-promoting peptides, including insulin and leptin. The laboratory has also defined the neural mechanisms by which highly palatable and energy dense foods can prime future food seeking and bias decision making about food. We also aim to understand mechanisms associated with changes in function of the orbitofrontal cortex, a region involved in goal directed behaviour by updating the current value of a reward and guiding actions based on this information. The laboratory has found that in obese rats or mice, plasticity occurs at the primary output neurons of the orbitofrontal cortex, a mechanism that is thought to influence goal directed behaviour.
Research on substance use disorder:
We also probe these circuits in the context of substance use disorders to understand how different neuromodulatory mechanisms contribute to synaptic rewiring of reward and decision-making circuits. Our lab has identified that the neuropeptides orexin and dynorphin, released from the lateral hypothalamus can act in the VTA to influence plasticity associated with drugs of abuse. However, it is unknown which specific VTA originating circuits they modify and how inhibiting orexin or kappa opioid receptors on these individual circuits can influence opioid or cocaine seeking. We use a variety of methods to identify how these neural circuits are modulated by this peptidergic input and how this contributes to craving or relapse to drug seeking. Understanding plasticity in neural circuits involved in reinforcement or goal-directed behaviour is of key importance to decode the function of neural circuits involved in the development of neuropsychiatric disorders including addiction, affective disorders, and maladaptive eating behaviour and may lead to the development of novel therapies.
The Borgland lab values creativity, scientific integrity, collaboration, determination, and a positive attitude.