Juliano S L, Ma W, Eslin D
Department of Anatomy and Cell Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814.
Proc Natl Acad Sci U S A. 1991 Feb 1;88(3):780-4. doi: 10.1073/pnas.88.3.780.
Although the role of acetylcholine in processing stimuli in the cerebral cortex is becoming defined, the impact of cholinergic activity on the character of cortical maps remains unclear. In the somatosensory cortex, topographic maps appear capable of lifelong modifications in response to alterations in the periphery. One factor proposed to influence this adaptational ability is the presence of acetylcholine in the cortex. The studies presented here, using the 2-deoxyglucose technique, demonstrate that the unilateral removal of a digit in cats, followed by stimulation of an adjacent digit, produces a pattern of metabolic activity in the somatosensory cortex that is dramatically expanded when compared with the opposite (normal) hemisphere. In contrast, experiments in which the somatosensory cortex was depleted of acetylcholine and the animal received a similar amputation led not to patterns of expanded metabolic activity, but rather to reductions in the evoked metabolic distribution. These studies implicate acetylcholine in normal map formation and in the maintenance of the capacity of cortical maps to adapt to changes in the periphery.
尽管乙酰胆碱在大脑皮层处理刺激过程中的作用正逐渐明确，但胆碱能活性对皮层图谱特征的影响仍不清楚。在躯体感觉皮层中，地形图似乎能够根据外周的变化进行终身修改。一个被认为影响这种适应能力的因素是皮层中乙酰胆碱的存在。此处呈现的研究使用2-脱氧葡萄糖技术表明，在猫身上单侧切除一个趾头，随后刺激相邻趾头，会在躯体感觉皮层产生一种代谢活动模式，与对侧（正常）半球相比，该模式显著扩大。相反，在躯体感觉皮层乙酰胆碱耗尽且动物接受类似截肢手术的实验中，并未导致代谢活动模式的扩大，而是诱发的代谢分布减少。这些研究表明乙酰胆碱在正常图谱形成以及皮层图谱适应外周变化能力的维持中发挥作用。
