Delayed precursor cell marker response in hippocampus following cold injury-induced brain edema.

The purpose of this study was to examine the possibility of neuronal remodeling and repair after cold injury-induced brain edema using immunoassays of nestin, 3CB2, and TUC-4. Male ddN strain mice were subjected to cold-induced cortical injury. Animals were divided into the following 6 groups: 1) 1-day after injury, 2) 1-week after injury, 3) 2-weeks after injury, 4) 1-month after injury, 5) sham, and 6) normal controls. Brain water content measurement, Western blot analysis, histological examination, and neurobehavioral examination were performed. Brain water content was significantly increased in the ipsilateral cortex at 1-day after injury. At 1-day and 1-week after injury, immunoreactivity of nestin, 3CB2, and TUC-4 were absent. Nestin was expressed in 3CB2-positive astrocytes at 1-month after injury, and nestin expression with TUC-4 was present in the hippocampal cell layer. Neurobehavioral function of the 1-month after injury group was significantly improved compared with function 1-day after injury. These results suggest that delayed precursor cell marker expression in glia and neuron-like cells might be part of adaptation to the injury. Although brain injury causes brain edema and neuronal death, there is the possibility of remodeling.