Ashe J H, McKenna T M, Weinberger N M
Center for the Neurobiology of Learning and Memory, University of California, Irvine 92717.
Synapse. 1989;4(1):44-54. doi: 10.1002/syn.890040106.
Exogenously applied muscarinic agonists--for example, acetylcholine (ACh) and acetyl-beta-methacholine (MCh)--modify frequency receptive fields in auditory cortex of unanesthetized animals in a frequency-specific rather than global manner. The present study sought to relate these findings to endogenous actions of ACh by using the anticholinesterase agents eserine sulphate and soman (0-1,2,2-trimethylpropylmethylphosphonofluoridate) to facilitate the effects of endogenous ACh. Frequency receptive fields (FRF) were determined by presenting sequences of different isointensity tones before, during, and after application of ACh, MCh, eserine, or soman; also the cholinesterase blockers were applied between applications of ACh or MCh. The major effects produced by the inhibitors were similar to those of the agonists. Predominant effects were frequency-specific changes in FRF. Further, eserine and soman, similar to ACh and MCh, produced shifts in the best frequency (BF) of FRF due mainly to coordinated depression of responses to the BF and increased responses to adjacent, non-BF. The results indicate that exogenous and endogenous ACh, acting via muscarinic receptors, can significantly influence the physiological functioning of cortical neurons and consequently their processing of sensory information.
外源性应用的毒蕈碱激动剂——例如乙酰胆碱（ACh）和乙酰-β-甲基胆碱（MCh）——以频率特异性而非全局性的方式改变未麻醉动物听觉皮层的频率感受野。本研究试图通过使用抗胆碱酯酶药物硫酸毒扁豆碱和梭曼（0-1,2,2-三甲基丙基甲基膦酰氟化物）来增强内源性ACh的作用，从而将这些发现与ACh的内源性作用联系起来。通过在应用ACh、MCh、毒扁豆碱或梭曼之前、期间和之后呈现不同等强度音调序列来确定频率感受野（FRF）；此外，在应用ACh或MCh之间应用胆碱酯酶阻滞剂。抑制剂产生的主要作用与激动剂相似。主要作用是FRF的频率特异性变化。此外，毒扁豆碱和梭曼与ACh和MCh相似，主要由于对最佳频率（BF）反应的协同抑制以及对相邻非BF频率反应的增加，导致FRF的最佳频率发生偏移。结果表明，外源性和内源性ACh通过毒蕈碱受体发挥作用，可显著影响皮层神经元的生理功能，进而影响其对感觉信息的处理。
