The satiety hormone leptin can act on non-neuronal cells in the brain and affect feeding behavior in mice, reports a study published online in Nature Neuroscience.
Leptin is a hormone released by fat cells in the body and is known to regulate feeding behavior and metabolism. Tamas Horvath and colleagues showed that astrocytes-a type of glial cell-in a part of the brain known to regulate feeding and metabolism, the hypothalamus, contain leptin receptors.
Deletion of the gene that encodes leptin receptors, from astrocytes, altered their shape, as well as changing the number of synapses formed by neurons in the hypothalamus. Leptin normally suppresses feeding, but in mice, with no astrocytic leptin receptors, its effects were lessened. Since hypothalamic neurons are known to control feeding behavior, changes in their connectivity brought about by deletion of astrocytic leptin receptors might underlie the resulting changes in feeding behavior.
This study is the first to show that leptin acts on astrocytes, in addition to its effects on neurons, adding another dimension to how the brain and its various cell types regulate feeding behavior.