Neurovascular Interaction and the Pathophysiology of Diabetic Retinopathy

Figure 1

Schematic diagram illustrating (i) the normal balance between neuronal activity and vascular function and (ii) the action of 5-methyl-I4AA in preventing the development of diabetic retinopathy. Arrows at the right and left of the figure represent the opposing forces that upset (red arrow) or restore (blue arrow) the normal balance between vascular and neuronal function in diabetes. Diabetes disrupts the functional integrity of the vascular system of the inner retina (red arrow) and tilts the balance indicator toward the production of tissue hypoxia/ischemia that induces DR. The resultant imbalance in neurovascular coupling (pathway (1)) increases the energy demands of retinal neurons and glial cells to further exacerbate the condition (dashed red line). 5-methyl-I4AA, by activating the GABA_C receptors, suppresses the activity of inner retinal neurons (blue arrow) and reduces their metabolic demand (dashed blue line). This process reestablishes the normal balance of the neuron-vascular relationship. See text for additional details.