Astrocytes—cells once widely described primarily as neuronal support—may be key intermediaries in how the brain translates a post-meal rise in glucose into satiety signals, according to a study published April 6, 2026, in the Proceedings of the National Academy of Sciences.
Researchers at the University of Concepción in Chile, working with collaborators at the University of Maryland, report evidence for a signaling chain in the hypothalamus that helps activate neurons associated with fullness after eating.
According to a University of Maryland news release carried by ScienceDaily, the team found that after a meal, rising glucose prompts hypothalamic tanycytes—specialized glial cells lining the third ventricle—to metabolize sugar and release lactate into nearby tissue. The researchers report that this lactate then activates astrocytes through the receptor HCAR1. In their experiments, activation of astrocytes was linked to glutamate release and increased excitability of POMC neurons, a population of hypothalamic neurons commonly associated with appetite suppression.
Ricardo Araneda, a professor in the University of Maryland’s Department of Biology and a corresponding author, said the work revises a prevailing view that lactate from tanycytes acts directly on appetite-regulating neurons. “Researchers used to think that lactate produced from tanycytes ‘spoke’ directly to neurons involved in appetite control,” Araneda said, adding that the team instead identified astrocytes as a key intermediary in the pathway.
The paper’s title—“Tanycyte-derived lactate activates astrocytic HCAR1 to modulate glutamatergic signaling and POMC neuron excitability”—reflects the mechanism described in the report and was published in the Proceedings of the National Academy of Sciences on April 6, 2026.
The researchers also reported that stimulating a single tanycyte could activate multiple nearby astrocytes, suggesting the signal can spread through local networks of glial cells.
The findings are based on animal experiments. The researchers noted that the relevant cell types exist in humans, but that additional studies would be needed to determine how closely the pathway maps onto human physiology and whether it can be safely manipulated.
Araneda said the astrocyte receptor HCAR1 could represent a potential therapeutic target—possibly as a complement to existing anti-obesity drugs—though he emphasized that future research would be required to test whether altering HCAR1 meaningfully changes eating behavior.
