Dr. Xiaobing Zhang

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Our lab is interested in neural circuits that control eating behavior and body weight. Using an integrated approach combining cutting-edge technologies (such as optogenetics and virus-mediated neural circuit tracing) and classical tools (such as brain slice electrophysiology, immunohistochemistry and behavioral assays), we seek to understand how neural circuits for feeding and reward are merged to regulate eating behavior and how the dysfunction in neural circuits causes eating disorders and obesity.

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Neural circuits for hedonic eating and eating disorders

Obesity is most commonly caused by excessive food intake and lack of physical activity. Nowadays, overconsumption of readily available and highly palatable food likely contributes to the growing rates of obesity worldwide. Binge eating disorder affects about 30% of obese individuals who seek body weight control. Palatable food containing sugar and fat is one of the most important risk factors for obesity with binge eating disorder. Interestingly, our recent studies indicate that the activation of an inhibitory neural circuit from zona incerta to paraventricular thalamus rapidly evokes binge-like eating of palatable food containing sugar and fat (Zhang & van den Pol, Science 2017). However, it remains unknown whether and how this circuit is involved in the pathological condition of eating disorders especially binge eating. Therefore, we are currently working on both zona incerta and paraventricular thalamus to answer the following questions:

• How are these nuclei regulated by other neurons with neurotransmitter and/or neuropeptide release?
• What is the downstream target of paraventricular thalamus for mediating binge-like eating evoked by activating neural circuit from zona incerta to paraventricular thalamus? Especially, how this pathway is connected to both brain emotion and reward centers for regulating hedonic eating?
• What is the role of zona incerta and paraventricular thalamus in binge eating disorders?

Hypothalamic neurons and energy homeostasis

We are also interested in the role of hypothalamic neurons in regulating food intake and body weight. We recently found that arcuate nucleus dopamine neurons play orexigenic role in energy homeostasis (Zhang & van den Pol, Nature Neurosci. 2016). However, the neural circuits based on arcuate nucleus dopamine neurons remain largely unknown. Currently, our efforts are focused on the functional connections between arcuate dopamine neuron and other neuron types that may participate in the regulation of food intake and other behaviors. Especially, we will study whether and how hypothalamic dopamine neurons send projections to brain regions outside of hypothalamus for functional regulation.