FIG. 6.
Spontaneous activity and evoked field potentials were recorded from an injured hippocampal slice using the SMEA. (A) A light micrograph of a hippocampal slice (2DIV) cultured on an SMEA with electrodes contacting the CA1, CA3, and DG regions. At 5DIV, the tissue and SMEA were biaxially stretched to 8.0% strain, and neuronal activity was monitored with the SMEA for an additional 9 days post-injury. (B) Immediately post-injury, spontaneous and continuous bursting was simultaneously recorded in multiple regions, which was not present before deformation. This bursting activity continued for 20 s and was then followed for 3 min by synchronized single bursts recorded on multiple electrodes simultaneously. Recordings from two electrodes (E05 in DG and E08 in CA3) are depicted. (C) Stimulus-response curves (stimulated at E05, n = 3) were generated immediately pre-injury (5DIV, pre-inj), immediately post-injury (5DIV, post-inj), 4 days post-injury (9DIV), and 9 days post-injury (14DIV) with the response recorded from E08 shown. The S/R curves were fit with sigmoidal functions. The maximum response amplitude (Rmax) decreased 36% at 9 days post-injury, indicating a loss of excitable neurons.