Microglial activation and vascular responses that are associated with early thalamic neurodegeneration resulting from thiamine deficiency.

•Neurotoxicity due to thiamine deficiency (TD) were histologically evaluated.•Microglial activation appeared in the thalamus between 7 and 8 days TD.•Astrocytosis and neurodegeneration did not appear until >24 h later.•Microglia “encapsulated” much of the thalamic vasculature within <10 days.•Vascular leakage and excitotocity were minimal even at ≤10 d TD.