Alterations of functional properties of hippocampal networks following repetitive closed-head injury.

摘要: Traumatic brain injury (TBI) is the leading cause of death for persons under age 45. Military service members who have served on multiple combat deployments and contact-sport athletes are at particular risk sustaining repetitive TBI (rTBI). Cognitive behavioral deficits resulting from rTBI well documented. Optimal associative LTP, occurring in CA1 hippocampal Schaffer collateral pathway, required both memory formation retrieval. Surprisingly, ipsilateral LTP evoked by 100 Hz tetanus was enhanced mice 3× closed head (3× CHI) treatment group comparison to contralateral or Sham area, spite reduced freezing during contextual fear conditioning one week following CHI. Electrophysiological activity neurons evaluated with whole-cell patch-clamp recordings. CHI exhibited significant increases action potential amplitude maximum rise decay slope while duration decreased. Recordings neuron postsynaptic currents were conducted detect spontaneous excitatory inhibitory (sEPSCs/sIPSCs) respective miniature (mEPSCs mIPSCs). In mice, sEPSCs sIPSCs had an increased frequency events but decreased amplitudes. addition, altered potential-independent currents. The mEPSCs larger Moreover, effect mIPSCs opposite that sIPSCs. Specifically, amplitudes increased. These results consistent a mechanism which closed-head affects function promoting remodeling synaptic inputs impairment hippocampal-dependent tasks.