Which of the following statements about retinal ganglion cells is NOT true?

• A. Each ganglion cell has a single axon that travels within the optic nerve
• B. Parvocellular cells are known as midget ganglion cells
• C. Magnocellular (M) cells project to layers 1-2 of the LGN
• D. Ganglion cells have the highest density in the fovea

Answer: (D)

The key idea is how retinal ganglion cells are arranged and distributed in the retina. Ganglion cells are the output neurons of the retina, and each one sends a single axon that becomes part of the optic nerve. The parvocellular (midget) pathway is carried by small, high-acuity ganglion cells, while magnocellular cells feed the magnocellular layers of the LGN (layers 1–2).

Regarding density, the fovea is the region of highest cone density and supports high visual acuity, but the very center of the fovea (the foveola) contains relatively few ganglion cell bodies because these cells are displaced to surrounding areas to optimize light access to the cones. Consequently, the greatest density of ganglion cells is not in the fovea's center; it reaches its peak in the parafoveal region surrounding the fovea. That’s why the statement about having the highest ganglion cell density in the fovea isn’t true.