Emerging Roles of Filopodia and Dendritic Spines in Motoneuron Plasticity during Development and Disease

Figure 4

Electrophysiological recordings of hypoglossal motoneurons from C57/Bl6 WT mice compared to GAD67-KO mice at E18 (for methodology see Kanjhan and Bellingham, 2013 [26]). (a-b) Somatic recordings of excitatory (downward deflections, long arrows, EPSCs) and inhibitory (upward deflections, short arrows, IPSCs) postsynaptic currents using low resistance electrodes (3-4 mΩ) at −60 mV and 0 mV holding potentials, respectively. (c-d) Dendritic recording of EPSCs (downward deflections, long arrows) and IPSCs (upward deflections, short arrows) at 0 mV holding potential using higher impedance electrodes (10–15 mΩ). (e-f) Current-clamp recording of membrane potential at action potential () firing threshold, showing subthreshold excitatory (long arrows, EPSPs) and inhibitory (short arrows, IPSPs) postsynaptic potentials. (g-h) Magnified baseline traces of (e)-(f), respectively. Scale bars = (a-b) = 50 pA, 0.1 s; (c-d) = 25 pA, 0.1 s; (e-f) = 20 mV, 1 s; and (g-h) = 3 mV, 1 s.

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