Traumatic brain injury (TBI) remains the leading cause of death and disability worldwide with no existing effective treatment. The early phase after TBI induction triggers numerous molecular cascades to regulate adaptive processes and cortical network activity. Kinases play a particularly prominent role in modifying peptide substrates, which include ion channels, receptors, transcription factors and inflammatory mediators. This project aimed to better understand the post-injury serine/threonine kinome; 1) Which kinases conduct phosphorylation-induced alterations of target peptides following unilateral TBI in mouse cortex? 2) How do these kinases effectuate pathological network hyperexcitability, which has detrimental longterm outcomes? We used a serine/threonine kinase assay at 4 hours, 24 hours and 72 hours post-TBI to identify hyper-/hypo-active/phosphorylated kinases and peptides in the ipsilateral and contralateral cortical hemispheres relative to sham-operated controls. We pharmacologically mimicked these kinase changes and using multielectrode array recordings we explored their electrophysiological implications on spontaneous and evoked cortical activity. The kinase assay revealed specific dynamic fluctuations in activity from hours to days post-injury, which – when pharmacologically mimicked – resulted in significant changes of spontaneous network activity and evoked synaptic signals, correlating with temporal network changes previously found after TBI in our lab. The contribution of specific target channel/receptor subunits was also shown. We conclude that volatile kinase activity has potent implications on cortical network activity after the injury and that these kinases and/or their peptide substrates should be more seriously considered as therapeutic targets for the clinical treatment of TBI. Supported by the German Research Foundation (DFG, CRC 1080,C02) to TM.