Rodent models of obesity induced by consuming high-fat diet (HFD) are characterized by inflammation both in peripheral tissues and in hypothalamic areas critical for energy homeostasis. Here we report that unlike inflammation in peripheral tissues, which develops as a consequence of obesity, hypothalamic inflammatory signaling was evident in both rats and mice within 1 to 3 days of HFD onset, prior to substantial weight gain. Furthermore, both reactive gliosis and markers suggestive of neuron injury were evident in the hypothalamic arcuate nucleus of rats and mice within the first week of HFD feeding. Although these responses temporarily subsided, suggesting that neuroprotective mechanisms may initially limit the damage, with continued HFD feeding, inflammation and gliosis returned permanently to the mediobasal hypothalamus. Consistent with these data in rodents, we found evidence of increased gliosis in the mediobasal hypothalamus of obese humans, as assessed by MRI. These findings collectively suggest that, in both humans and rodent models, obesity is associated with neuronal injury in a brain area crucial for body weight control.

Effective mentorship is likely one of the most important determinants of success in academic medicine and research. Many papers focus on mentoring from the mentor's perspective, but few give guidance to mentees forging these critically important relationships. The authors apply "managing up," a corporate concept, to academic medical settings both to promote effective, successful mentoring and to make a mentor's job easier. Managing up requires the mentee to take responsibility for his or her part in the collaborative alliance and to be the leader of the relationship by guiding and facilitating the mentor's efforts to create a satisfying and productive relationship for both parties. The authors review the initiation and cultivation of a mentoring relationship from the perspective of a mentee at any stage (student through junior faculty), and they propose specific strategies for mentee success.