How do zona incerta and paraventricular thalamus regulate food intake and eating disorders?

Although the central mechanism of binge eating disorder remains largely unknown, more and more studies suggest that the dysfunctional reward system of the brain is involved in the development of binge eating disorder. Recently, we reported that activation of the inhibitory neural circuits from zona incerta to paraventricular thalamus rapidly evoked binge-like eating of palatable food (Zhang and van den Pol, 2017). Based on this finding, we currently focus on the zona incerta and paraventricular thalamus to further understand how these regions receive neural projections from feeding-related brain areas and send signals to the brain's reward and emotion centers for the regulation of food intake and feeding motivation. We also study how neural circuits connecting to the zona incerta and the paraventricular thalamus are altered by high-fat diet and other conditions that are involved in the development of obesity and eating disorders.

How do neuropeptides produced by hypothalamic neurons affect food intake and feeding motivation?

Hypothalamic neurons play a critical role in controlling the energy homeostasis of our body. Using slice electrophysiology in combination with optogenetics, we study how neuropeptide signaling regulate feeding motivation. We are also interested in the functional circuit connection of hypothalamic neurons to other brain areas outside of the hypothalamus such as brain reward and emotion centers. Recently, we reported that oxytocin promotes feeding motivation in stress conditions but not normal food intake through targeting the paraventricular thalamus (Barrett and Zhang, 2021). These interesting findings suggest a novel oxytocin neural pathway in feeding regulation different from what was reported for the inhibition of food intake by previous studies. We will further study how oxytocin signaling in the paraventricular thalamus regulates feeding-related behaviors through functional neural circuit connections.

How are tyrosine-hydroxylase-expressing neurons involved in the regulation of feeding motivation and food intake?

In the brain, tyrosine hydroxylase is expressed in several regions for the synthesis of catecholamine including dopamine, norepinephrine, and epinephrine which are important for functional behavioral regulation. We are particularly interested in tyrosine-hydroxylase-expressing neurons out of the midbrain for their role in feeding regulation. Our previous study already revealed functional neural circuits of arcuate nucleus dopamine neurons in the regulation of food intake (Zhang and van den Pol, 2015 and 2016). We will further study how these dopamine neurons and other hydroxylase neurons such as zona incerta dopamine neurons and locus coerulease norepinephrine neurons regulate feeding motivation and food intake.