Insulin peptides and the body-brain dialog
Ignacio Torres Aleman
Laboratory of Neurobiology of Insulin Peptides, ACHUCARRO
The brain receives external (sensory) and internal (interoceptive) information and computes it to produce behavioral outputs accordingly. Internal bodily states are transmitted to the brain through interoceptive pathways comprising humoral factors and the peripheral nervous system. Many body-to-brain signals have been extensively analyzed concerning their brain targets, actions, and circuits involved. However, the long-held concept of the blood-brain-barrier (BBB) as an unsurmountable wall isolating the brain from the periphery, has hindered progress in the understanding of peripheral humoral signals as modulators of brain function. This is exemplified by the relatively old observation that circulating insulin modulates central control of glucose metabolism in parallel with a striking lack of understanding of how this hormone reaches its brain targets. Due to the realization that insulin peptides (ILPs) are readily detected in brain, while their local synthesis is low, we have concentrated part of our efforts in understanding mechanisms of passage of circulating ILPs into the brain across the BBB. Our recent work focuses on the role of astrocytes as gatekeepers of the entrance of ILPs, and their capacity to integrate ILPs actions on higher brain functions. I will discuss evidence that insulin and IGF-I receptors in astrocytes are involved in passage of these circulating ILPs into the brain to coordinate energy allocation impacting on behavioral outputs.
Currently we are hosting our seminar in Zoom. Internal seminars are devoted to the ACHUCARRO staff.