Neurophysiological Study of Traumatic Brain Injury To Slice or Not to Slice

Diffuse axotomy is characteristic of mild traumatic brain injury (TBI) both clinically and in experimental models. Axotomy also occurs during preparation of acute brain slices for physiological recordings. Brain slices have been used for decades and have many advantages, including the ability to select cells within particular locations or with specific morphologies for study. The question addressed here is whether creating additional axotomy by preparing brain slices introduces additional injury that is already typical of TBI. We have previously demonstrated alterations in both intrinsic membrane and synaptic properties recorded in brain slices after mTBI. Here we examined whether axotomized neurons differ from intact neurons in slices made from naïve mouse pups. There was no significant difference in either excitatory synaptic postsynaptic currents or in any measures of intrinsic membrane and cellular properties. These results suggest that creating the brain slices does not induce alterations similar to that observed within two days of mTBI induced by fluid percussion injury. Thus ex vivo slices are an appropriate methodology to study the effects of TBI.