丰富环境干预对小鼠梨状皮层锥体神经元兴奋性的影响

Effects of enriched environment intervention on excitability of pyramidal neurons in piriform cortex of mice

目的探讨丰富环境干预下的小鼠梨状皮层锥体神经元兴奋性的变化特点。方法选用15日龄的C57BL/6小鼠30只,随机分为丰富环境组(EE组)15只和常规环境组(SE组)15只,EE组采用丰富环境刺激饲养3周,SE组则在正常实验室环境下饲养3周。全细胞电流钳模式下记录小鼠梨状皮层锥体神经元的各电生理指标,锥体神经元的兴奋性指标包括动作电位间距(ISI)、能障(Vts-Vr)和绝对不应期(ARP)。结果与常规环境组比较,丰富环境干预下的小鼠梨状皮层神经元的ISI减小(P<0.05),Vts-Vr降低(P<0.05),ARP缩短(P<0.05)。结论丰富环境干预可提高梨状皮层锥体神经元的兴奋性,提示丰富环境可能有助于梨状皮层锥体神经元的发育成熟。

Objective To investigate the changes of the excitability of pyramidal neurons in the piriform cortex influenced by enriched environment（ EE）. Methods Thirty C57 BL/6 mice of 15 day age were divided into 2 groups as follows： fifteen mice were reared in EE for 3 weeks（ EE group） and the others were reared in standard environment（ SE） for 3 weeks（ SE group） randomly. Current-clamp recordings with whole-cell patch clamp were made in pyramidal neurons of the piriform cortex. The excitability indexes of pyramidal neurons include inter-spike intervals（ ISI）,energy barrier（ Vts-Vr） and absolute refractory periods（ ARP）. Results The pyramidal neurons of the piriform cortex had lower Vts-Vr（ P 〈 0. 05） and shorter ARP in EE group compared with SE group（ P 〈0. 05）. Meanwhile,the ISI values significantly decreased in EE group compared with SE group（ P 〈 0. 05）. Conclusion Rearing in EE can enhance the pyramidal neuron sensitivity of the piriform cortex which indicates enriched environment may help to accelerate pyramidal neurons development and maturate.