Hovarth’s team also found something unexpected, however. In response to cannabinoid receptor stimulation, another set of neurons in the mice’s brains got to work. These neurons are called POMC neurons, short for hypothalamic pro-opiomelanocortin neurons. In previous studies, scientists found that activating POMC neurons makes animals eat less. Yet when cannabinoids were around, the POMC neurons totally switched jobs, making the mice eat more.