Is the majority of ATP produced in photoreceptors generated through aerobic or anaerobic glycolysis?

The majority of ATP produced in photoreceptors is generated through aerobic glycolysis. Photoreceptors, specifically rods and cones in the retina, have a significant requirement for ATP to support various functions, including the phototransduction cascade and maintaining ionic gradients necessary for neurotransmission.

Aerobic glycolysis occurs in the presence of oxygen and allows for a more efficient conversion of glucose into ATP compared to anaerobic glycolysis. In the presence of oxygen, glucose is ultimately metabolized through the Krebs cycle and oxidative phosphorylation, resulting in a much higher yield of ATP (approximately 36-38 ATP molecules from one glucose molecule) than anaerobic glycolysis, which primarily produces only 2 ATP molecules.

Photoreceptors are well-vascularized and have access to a rich supply of oxygen through the choroidal circulation, facilitating aerobic processes. While they can utilize some anaerobic glycolysis under specific conditions (such as low oxygen), the predominant mode of ATP production is through aerobic glycolysis, supporting their high energy demands effectively.