Neurons in the diagonal band of Broca moderate food intake

Abstract

Identifying neurological mechanisms that regulate feeding behaviour could help to advance the treatment and prevention of obesity and eating disorders. New research in mice has identified and localized a population of neurons that promotes eating to satiate hunger and reduces the desire to eat simply for pleasure.

One subset of these DBB^PENK neurons projects from the DBB to the paraventricular nucleus of the hypothalamus (PVH) and another subset projects to the lateral nucleus of the hypothalamus (LH). The researchers hypothesized that these two neuronal subpopulations have different roles in feeding control. To test this hypothesis, the researchers compared how strongly PVH-projecting DBB^PENK neurons and LH-projecting DBB^PENK neurons responded when fasted or fed mice were given either normal chow or fatty, sugary food. They demonstrate that PVH-projecting DBB^PENK neurons are more responsive to food presentation in fasted mice than in satiated mice. This was true whether the researchers gave the mice normal chow or fatty, sugary food. LH-projecting DBB^PENK neurons, on the other hand, were more active when mice were presented with sugary, fatty food than when they were given normal chow. This response was seen in both fasted and fed mice. The investigators also showed that optogenetic stimulation of PVH-projecting DBB^PENK neurons promoted increased feeding in mice, whereas stimulating LH-projecting DBB^PENK neurons caused the animals to eat less than wild-type controls.