TNF and obesity due to melanocortin 4 receptor deficiency: This hypothesis is supported by the observation that during obesity, POMC neurons present a higher percentage of microglial contacts (151), suggesting that microglial TNFα constant release during obesity might affect POMC activity and even induce neurotoxicity since there is a significant decrease in the number of POMC neurons after chronic feeding with a high fat and carbohydrate diet (151).