Synaptic Reorganization in an Experimental Model of Posttraumatic Epilepsy

Abstract

Synaptic Activity in Chronically Injured, Epileptogenic Sensorimotor NeocortexLi H, Prince DJ Neurophysiol 2002;88:2–12We recorded spontaneous and evoked synaptic currents in pyramidal neurons of layer V in chronically injured, epileptogenic neocortex to assess changes in the efficacy of excitatory and inhibitory neurotransmission that might promote cortical hyperexcitability. Partial sensory-motor neocortical isolations with intact blood supply (“undercuts”) were made in 20 rats on postnatal day 21–25 and examined 2–6 weeks later in standard brain slice preparations by using whole-cell patch-clamp techniques. Age-matched, uninjured naive rats (n = 20) were used as controls. Spontaneous and miniature excitatory and inhibitory postsynaptic currents (s- and mEPSCs; s- and mIPSCs) were recorded by using patch-clamp techniques. The average frequency of s- and mEPSCs was significantly higher, whereas that of s- and mIPSCs was significantly lower in neurons of undercuts versus controls. The increased frequency ...