I scribbled together this diagram to try and make sense of the ANLSH - The astrocyte-neuron lactate shuttle hypothesis. The published literature isn’t entirely easy on this one. However, what I have gathered is that when neurons are firing more, they are using more energy. This will be reflected by the increased neurotransmitter (Glutamate; Glu) being released. Astrocytes at the synapse take up the glutamate once it has done its job, along with 3Na+ to maintain the electrochemical balance, but the excess Na+ must then be exported in an energy dependent manner. All in all, this import/export of Glu and Na+ leads to a corresponding energy consumption increase, with the neuron. As a a result, the astrocyte produces more Lactate, a by product of anaerobic glycolysis. The lactate is then shuttled out of the astrocyte and taken up by the active neurons to supplement their energy needs. The astrocyte also sends signals to local blood vessels to stimulate their dilation, increasing local blood flow, and increasing local oxygen and glucose to power the increased neuronal activity. All in all, the ANLSH and the associate physiology is a key concept in neuroenergetics, and underlies the interpretation of fMRI scans.
 Project Erythropoietin continues…

I scribbled together this diagram to try and make sense of the ANLSH - The astrocyte-neuron lactate shuttle hypothesis. The published literature isn’t entirely easy on this one. However, what I have gathered is that when neurons are firing more, they are using more energy. This will be reflected by the increased neurotransmitter (Glutamate; Glu) being released. Astrocytes at the synapse take up the glutamate once it has done its job, along with 3Na+ to maintain the electrochemical balance, but the excess Na+ must then be exported in an energy dependent manner. All in all, this import/export of Glu and Na+ leads to a corresponding energy consumption increase, with the neuron. As a a result, the astrocyte produces more Lactate, a by product of anaerobic glycolysis. The lactate is then shuttled out of the astrocyte and taken up by the active neurons to supplement their energy needs. The astrocyte also sends signals to local blood vessels to stimulate their dilation, increasing local blood flow, and increasing local oxygen and glucose to power the increased neuronal activity. All in all, the ANLSH and the associate physiology is a key concept in neuroenergetics, and underlies the interpretation of fMRI scans.

 Project Erythropoietin continues…