Spontaneous synaptic activity of subplate neurons in neonatal rat somatosensory cortex
Spontaneous synaptic activity of subplate neurons in neonatal rat somatosensory cortex
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DOI：
10.1093/cercor/11.5.400
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发表时间：
2001-05-01
期刊：
影响因子：
3.7
通讯作者：
Luhmann, HJ
中科院分区：
文献类型：
--
作者：
Hanganu, IL;Kilb, W;Luhmann, HJ
亚板神经元在早期皮质发育中起重要作用。为了研究这些瞬时神经元是否接受突触输入，我们进行了全细胞记录从视觉识别和biocytin-labeled subplate细胞在体感皮层切片出生后0-3天的大鼠。亚板神经元的平均静息膜电位为-55mV，输入电阻约为1.1G Ω。阈上电流刺激67%的细胞在4-13 Hz范围内产生重复动作电位，其余33%的细胞只出现一个峰电位。可以鉴定三类自发突触后电流（sPSC）：（i）快速sPSC，平均振幅为14 pA，衰减时间为6.3ms，在（+/-）-γ-氨基-3-羟基-5-甲基异恶唑-4-丙酸（AMPA）/红藻氨酸受体阻断期间其频率降低95%.环噻嗪导致衰减时间增加3.5倍，表明快速sPSC由AMPA受体介导。(ii)慢sPSC，18 pA的振幅和51.2 ms的衰减时间被阻断的N-甲基-D-天冬氨酸（NMDA）受体拮抗剂CPP。(iii)氯化物驱动的sPSC，振幅为34.4 pA，衰减时间为123 ms，被γ-氨基丁酸A（GABA（A））受体拮抗剂gabazine阻断。虽然柠檬酸河豚毒素（TTX）完全阻断NMDA介导的stow sPSC，但mt中AMPA和GABA（A）介导的sPSC的频率分别降低了55%和90%。这些结果表明，亚板神经元接受AMPA、NMDA和GABA（A）受体介导的功能性突触输入。
Subplate neurons play an important role in early cortical development. To investigate whether these transient neurons receive synaptic inputs, we performed whole-cell recordings from visually identified and biocytin-labeled subplate cells in somatosensory cortical slices from postnatal day 0-3 rats. Subplate neurons had an average resting membrane potential of -55 mV and input resistance of similar to1.1 G Ohm. Suprathreshold current injection elicited in 67% of the cells repetitive action potentials at 4-13 Hz and the remaining 33% showed only one spike. Three classes of spontaneous postsynaptic currents (sPSCs) could be identified: (i) Fast sPSCs, with an average amplitude of 14 pA and a decay time of 6.3 ms, which showed a 95% decrease in their frequency during (+/-)-gamma -amino-3-hydroxy-5-methylisoxazote-4-propionic acid (AMPA)/kainate receptor blockade. Cyclothiazide caused a 3.5-fold increase in the decay time, indicating that fast sPSCs were mediated by AMPA receptors. (ii) Slow sPSCs, with 18 pA amplitude and 51.2 ms decay time were blocked by the N-methyl-D-aspartate (NMDA) receptor antagonist CPP. (iii) Chloride-driven sPSCs, with 34.4 pA amplitude and 123 ms decay time that were blocked by the gamma -amino-butyric acid A (GABA(A)) receptor antagonist gabazine. While tetrodotoxin citrate (TTX) blocked completely NMDA-mediated stow sPSCs, the frequency of AMPA- and GABA(A)-mediated sPSCs was reduced in mt by 55 and 90%, respectively. These results indicate that subplate neurons receive functional synaptic inputs mediated by AMPA, NMDA and GABA(A) receptors.