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:
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.
Zhang X, van den Pol AN. (2017) Rapid binge-like eating and body weight gain driven by zona incerta GABA neuron activation. Science. 356(6340): 853-859.
Zhang X, van den Pol AN. (2016) Hypothalamic arcuate nucleus tyrosine hydroxylase neurons play orexigenic role in energy homeostasis. Nature Neuroscience. 19(3): 1341-1347.
Zhang X, van den Pol AN. (2015) Dopamine/tyrosine hydroxylase neurons of the hypothalamic arcuate nucleus release GABA, communicate with dopaminergic and other arcuate neurons, and respond to dynorphin, met-encephalin and oxytocin. The Journal of Neuroscience. 35(45): 14966-14982.
Zhang X, van den Pol AN. (2013) Direct inhibition of arcuate nucleus POMC neurons- a potential mechanism for the orexigenic actions of dynorphin. The Journal of Physiology. 591: 1731-1747.
Zhang X, van den Pol AN. (2012) Thyrotropin-releasing hormone (TRH) inhibits melanin concentrating hormone neurons- implications for TRH-mediated anorexic and arousal actions. Journal of Neuroscience. 32(9): 3032-3043.
Zhang X, Spergel DJ. (2012) Kisspeptin inhibits high-voltage activated Ca2+ Channels in GnRH neurons via multiple Ca2+ influx and release pathways. Neuroendocrinology. 96(1): 68-80.
Zhang X, Sun, GC, Liu, LY, Yu F, Xu TL.H (2008) Alpha-2 subunit specificity of cyclothiazide inhibition on glycine receptors. Molecular Pharmacology. 73: 1195-1202.
Zhang X, Jiang P, Gong N, Hu XL, Fei D, Xiong ZQ, Xu L, Xu TL. (2008) A-type GABA receptor as a central target of TRPM8 agonist menthol. PLoS ONE. 3(10): e3386.
Han W, Tellex LA, Rangel MJ, Motta SC, Zhang X, Perez IO, Canteras NS, Shammah-Lagnado SJ, van den Pol AN, de Araujo IE. (2017) Integrated control of predatory hunting by central nucleus of the amygdala. Cell. 168(1): 311-324.
Tellez LA, Han W, Zhang X, Ferreira TL, Shammah-lagnado S, Perez IO, van den Pol AN, de Araujo IE. (2016) Separate circuitries encode the hedonic and nutritional value of sugar. Nature Neuroscience. 19(3): 465-470 .