Kiyatkin Eugene A
Behavioral Neuroscience Branch, National Institute on Drug Abuse - Intramural Research Program, National Institutes of Health, DHHS, Baltimore, MD 21224, USA.
Neuroscience. 2020 Dec 15;451:240-254. doi: 10.1016/j.neuroscience.2020.09.050. Epub 2020 Oct 1.
Direct interaction of cocaine with centrally located monoamine transporters is the primary mechanism underlying its reinforcing properties. It is also often assumed that this drug action is responsible for all the physiological and behavioral effects of this drug. The goal of this review is to challenge this basic mechanism and demonstrate the importance of peripheral actions of cocaine in inducing its initial, rapid neural effects. The use of high-resolution electrophysiological, neurochemical and physiological techniques revealed that the effects of intravenous cocaine at behaviorally relevant doses are exceptionally rapid and transient correlating with strong, quick, and transient increases in blood cocaine levels. Some of these effects are mimicked by cocaine-methiodide, a cocaine analog that cannot cross the blood-brain barrier and they are resistant to dopamine (DA) receptor blockade. Therefore, it appears that rapid neural effects of cocaine result from its direct interaction with receptive sites on afferents of sensory nerves densely innervating blood vessels. This interaction creates a rapid neural signal to the CNS that results in generalized neural activation and subsequent changes in different physiological parameters. This drug's action appears to be independent from cocaine's action on central neurons, which requires a definite time to occur and induce neural and physiological effects with longer latencies and durations. The co-existence in the same drug on two timely distinct actions with their subsequent interaction in the CNS could explain consistent changes in physiological and behavioral effects of cocaine following their repeated use, playing a role in the development of drug-seeking and drug-taking behavior.
可卡因与位于中枢的单胺转运体的直接相互作用是其强化特性的主要潜在机制。人们还常常认为这种药物作用是该药物所有生理和行为效应的原因。本综述的目的是挑战这一基本机制,并证明可卡因外周作用在诱导其初始快速神经效应方面的重要性。使用高分辨率电生理、神经化学和生理技术发现,静脉注射可卡因在行为相关剂量下的效应异常迅速且短暂,与血液中可卡因水平的强烈、快速和短暂升高相关。其中一些效应可被不能穿过血脑屏障的可卡因类似物甲基碘化可卡因模拟,并且它们对多巴胺(DA)受体阻断具有抗性。因此,似乎可卡因的快速神经效应是由于其与密集支配血管的感觉神经传入纤维上的受体位点直接相互作用所致。这种相互作用向中枢神经系统产生一个快速神经信号,导致全身性神经激活以及随后不同生理参数的变化。这种药物的作用似乎独立于可卡因对中枢神经元的作用,后者需要一定时间才会发生并诱导具有更长潜伏期和持续时间的神经和生理效应。同一药物在两种时间上不同的作用及其随后在中枢神经系统中的相互作用并存,可能解释了可卡因反复使用后其生理和行为效应的持续变化,在寻求药物和用药行为的发展中起作用。