Which wave is primarily generated by glial cells and the retinal pigment epithelium?

Which wave is primarily generated by glial cells and the retinal pigment epithelium?

• A. a-wave
• B. b-wave
• C. c-wave
• D. d-wave

Answer: (C)

In electroretinography, different waves reveal activity from different parts of the retina. The slow, positive deflection that follows the initial negative dip is tied to the outer retina, mainly reflecting the retinal pigment epithelium and nearby glial cells (the Müller cells). When photoreceptors respond to light, potassium accumulates in the subretinal space. The RPE pumps ions and, together with the glial support of Müller cells, shifts the surrounding voltage, producing this gradual, sustained change—the c-wave. This makes the c-wave a marker of outer-retina and RPE function. The a-wave comes from photoreceptor phototransduction, and the b-wave from inner retinal neurons (bipolar cells) with some glial contribution, so the c-wave specifically points to the activity of glial cells and the RPE.

In electroretinography, different waves reveal activity from different parts of the retina. The slow, positive deflection that follows the initial negative dip is tied to the outer retina, mainly reflecting the retinal pigment epithelium and nearby glial cells (the Müller cells). When photoreceptors respond to light, potassium accumulates in the subretinal space. The RPE pumps ions and, together with the glial support of Müller cells, shifts the surrounding voltage, producing this gradual, sustained change—the c-wave. This makes the c-wave a marker of outer-retina and RPE function. The a-wave comes from photoreceptor phototransduction, and the b-wave from inner retinal neurons (bipolar cells) with some glial contribution, so the c-wave specifically points to the activity of glial cells and the RPE.