Evidence that stress activates glial lactate formation in vivo assessed with rat hippocampus lactography

Extracellular lactate of the rat hippocampus is inter alia increased by immobilization stress. The origin of lactate is, however, not well established, so it is not known whether it is mainly derived form neurons or glial cells. Dialysates were collected shortly (1 or 2 days) or with a delay (14 or 15 days) after implantation of the probe. In the short-term experiment lactate increased after stress, both with or without glucose added to the perfusate. In the long-term experiment there was marked gliosis around the dialysis probe and the stress effects were seen only in the presence of 5 mM glucose. The results are consistent with the idea that stress induces glycogenolysis and lactate export from astroglial cells via neurotransmitter or hormonal related processes.