Doyle Seán, Doran Michelle M, Cunningham Colm, Lowry John Patrick
Neurochemistry Laboratory, Department of Chemistry, Maynooth University, Maynooth, Co. Kildare, Ireland.
School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute & Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.
Eur J Neurosci. 2025 Nov;62(9):e70291. doi: 10.1111/ejn.70291.
The measurement of choline as a biomarker for in vivo cholinergic neurotransmission is a valuable tool in the study of a range of CNS pathologies. However, the continuous detection of cholinergic neurotransmission in selective brain regions in the mouse brain remains challenging and underexploited. Here, we have refined an established choline oxidase (ChOx) microelectrochemical biosensor and validated its use for long-term recording in the freely moving mouse. Using a 75-μm diameter polymer-ChOx composite disc electrode, we have successfully monitored stable and reproducible chronic real-time changes in choline-induced amperometric currents in vivo. Local infusions of choline and acetylcholine resulted in an increase in biosensor current in the hippocampus, while the inhibition of endogenous acetylcholinesterase (with neostigmine) significantly attenuated the response to exogenous acetylcholine. Systemic administration of donepezil produced a pronounced decrease in current in both the prefrontal cortex and hippocampus, with scopolamine and amphetamine resulting in signal increases that were not observed in animals with selective saporin lesioning (murine-p75) of the cholinergic basal forebrain. Furthermore, continuous biosensor recording in both regions displayed diurnal oscillations across repetitive light-dark phases. All are consistent with successful monitoring of endogenous changes in cholinergic neurotransmission.
将胆碱作为体内胆碱能神经传递的生物标志物进行测量，是研究一系列中枢神经系统疾病的一项重要工具。然而，在小鼠大脑的特定脑区持续检测胆碱能神经传递仍然具有挑战性且未得到充分利用。在此，我们改进了一种已有的胆碱氧化酶（ChOx）微电化学生物传感器，并验证了其在自由活动小鼠中进行长期记录的用途。使用直径为75μm的聚合物 - ChOx复合圆盘电极，我们成功监测了体内胆碱诱导的安培电流的稳定且可重复的慢性实时变化。向海马体局部注入胆碱和乙酰胆碱导致生物传感器电流增加，而抑制内源性乙酰胆碱酯酶（用新斯的明）显著减弱了对外源性乙酰胆碱的反应。多奈哌齐的全身给药使前额叶皮质和海马体中的电流均显著降低，东莨菪碱和苯丙胺则导致信号增加，而在胆碱能基底前脑选择性皂草素损伤（小鼠 - p75）的动物中未观察到这种信号增加。此外，在这两个区域进行的连续生物传感器记录显示，在重复的明暗周期中存在昼夜振荡。所有这些都与成功监测胆碱能神经传递的内源性变化一致。
