Effect of different fluctuations of membrane potential on the intrinsic characteristics of GABA neurons in mouse cerebral cortex

ObjectiveTo explore the effects of different fluctuations of membrane potential on the intrinsic characteristics and regulation of neural coding of GABA-ergic neurons in mouse cerebral cortex.

MethodsThe brain slices were prepared from FVB-Tg(Gad GFP) 4570Swn/J mice(postnatal day 15-20), and incubated in artificial cerebrospinal fluid with sufficient oxygenation for 2 h.The effects of fast post-polarization(fAHP), slow post-hyperpolarization(sAHP), different repolarization of action potential and fast post-polarization(fADP) on the intrinsic characteristics of neurons and regulation of neural coding were further studied by whole-cell recording.

ResultsCompared with sAHP, the absolute refractory period(ARP₂) and threshold(vts-Vr₃) of the action potential under the influence of fAHP were shorter and higher, respectively(P < 0.01).Compared with fAHP, the ARP₂ was shorter when the action potential was not fully repolarized, and the ARP₂ was the shortest when the threshold intensity was 0.25 times(P < 0.05).Compared with fAHP, the lower the fADP level was, the shorter the ARP₂ was, and the ARP₂ was the shortest at the resting potential level(P < 0.05).

ConclusionsAfter the integrating synaptic input, the plasticity of intrinsic characteristics of cerebral cortex GABA-ergic neurons changes when the membrane potential fluctuates.Different input modes affect the intrinsic characteristics of action potential of cerebral cortex GABA-ergic neurons, thereby regulating the programming ability of GABA-ergic neurons to input signals.