Recovery of Syrian hamster hippocampal signaling following its depression during oxygen-glucose deprivation is enhanced by cold temperatures and by hibernation

摘要

Signal transmission over a hippocampal network of CA3 and CA1 neurons in Syrian hamsters (Mesocricetus auratus), facultative hibernators, has not been fully characterized in response to oxygen-glucose deprivation (OGD). We hypothesized that during OGD, hippocampal signal transmission fails first at the synapse between CA3 and CA1 pyramidal neurons and that recovery of signal processing following OGD is more robust in hippocampal slices at cold temperature, from hamsters vs. rats, and from hibernating vs. non hibernating hamsters. To test these hypotheses, we recorded fEPSPs and population spikes of CA! neurons at 25 degrees C, 30 degrees C, and 35 degrees C in 400 pm slices over a 15 min control period with the slice in oxygenated aCSF containing glucose (control solution), a 10 min treatment period (OGD insult) where oxygen was replaced by nitrogen in aCSF lacking glucose, and a 30 min recovery period with the slice in the control solution. The initial site of transmission failure during OGD occurred at the CA3-CA1 synapse, and recovery of signal transmission was at least, if not more (depending on temperature), complete in slices from hibernating vs. non-hibernating hamsters, and from non-hibernating hamsters vs. rats. Thus, hamster neuroprotective mechanisms supporting functional recovery were enhanced by cold temperatures and by hibernation. (C) 2016 Elsevier Ireland Ltd. All rights reserved.