小檗碱对清醒家兔脑电图及功率谱的影响1

目的 观察小檗碱(berberine,Ber)对清醒家兔脑电图(EEG)及功率谱的影响,探讨Ber 改善学习记忆的神经生物学机制。方法 利用慢性埋藏电极记录清醒家兔海马和脑皮层EEG 及功率谱。结果 Ber 1~4 mg·kg^-1iv 能使清醒家兔脑皮层区EEG 出现持续低振幅快波,其主频率功率明显减少,并使海马区EEG 出现持续且有规律的θ节律,海马区主频率从δ段右移至θ段,主频率功率明显减少。Ber 2 mg·kg^-1iv 可逆转氢溴酸东莨菪碱0.3 mg·kg^-1iv引起的高振幅慢波和主频率增高的作用,同样家兔侧脑室每只注射Ber 0.05 mg 所引起的EEG 及功率谱变化亦可被氢溴酸东莨菪碱0.2 mg·kg^-1iv 所逆转,而不能通过血脑屏障的丁溴酸东莨菪碱0.4 mg·kg^-1iv 却无此作用。结论 Ber 通过影响中枢胆碱能系统在海马产生θ节律,减低皮层功率,可能是其改善和促进学习记忆的神经生物学机制之一。

Effects of berberine on EEG and EEG power spectrum recorded in conscious rabbits

Aim In order to study the mechanisms of underlying improving learning and memory in rodent,the effects of berberine (Ber)on EEG and EEG pow erspectrum were recorded in conscious rabbits.Methods EEG and EEG power spectrum were recorded in conscious rabbits with chronical implanted elect rodes.Results Ber at doses of 1~4mg·kg^-1iv showed to decrease dose-dependently the spect rum power of delta dominant frequency in cortical area and transfer the dominant frequency from delta to thetarhy thm in hippo campus.Under the same conditions,the effects of physostigmine 0.1mg·kg^-1iv on EEG were similar to Ber.Ber 2mg·kg^-1iv reversed significantly these effects of Ber 0.05 mg/rabbitivon EEG and power spectrum,but scopolamine butylbromide 0.4mg·kg^-1iv,which can not pass the blood-brain barrier,did not.Conclusion The effects of Ber are closely related to the action on the central cholinergic system.