Lactate in the brain has long been associated with ischaemia; however, more recent evidence shows that it can be found there under physiological conditions. In the brain, lactate is formed predominantly in astrocytes from glucose or glycogen in response to neuronal activity signals. Thus, neurons and astrocytes show tight metabolic coupling. Lactate is transferred from astrocytes to neurons to match the neuronal energetic needs, and to provide signals that modulate neuronal functions, including excitability, plasticity and memory consolidation. In addition, lactate affects several homeostatic functions. Overall, lactate ensures adequate energy supply, modulates neuronal excitability levels and regulates adaptive functions in order to set the 'homeostatic tone' of the nervous system.

长期以来，大脑中的乳酸与缺血有关。但是，最近的证据表明，可以在生理条件下在那找到它。在大脑中，响应神经元活动信号，主要由葡萄糖或糖原在星形胶质细胞中形成乳酸。因此，神经元和星形胶质细胞显示紧密的代谢耦合。乳酸从星形胶质细胞转移到神经元，以满足神经元的能量需求，并提供调节神经元功能（包括兴奋性，可塑性和记忆巩固）的信号。另外，乳酸影响几种稳态功能。总体而言，乳酸可确保充足的能量供应，调节神经元兴奋性水平并调节适应性功能，以设定神经系统的“稳态调”。