Which retinal layer contains synapses between bipolar cells and ganglion cells?

Which retinal layer contains synapses between bipolar cells and ganglion cells?

• A. Outer plexiform layer.
• B. Inner plexiform layer.
• C. Photoreceptor layer.
• D. Outer nuclear layer.

Answer: (B)

The key idea is where the signal from bipolar cells is passed to ganglion cells in the retina. Bipolar cells receive input from photoreceptors in the outer plexiform layer and then relay signals onward to ganglion cells, with amacrine cells helping shape the signal, within the inner plexiform layer. That inner plexiform layer is where the synapses between bipolar cells and ganglion cells (and their interneuronal partners) occur. The other layers serve different stages of the pathway: the outer plexiform layer connects photoreceptors to bipolar and horizontal cells; the outer nuclear layer contains photoreceptor cell bodies; the inner nuclear layer contains the cell bodies of bipolar, amacrine, and horizontal cells. The inner plexiform layer is thus the site of bipolar-to-ganglion communication, making it the correct choice.

The key idea is where the signal from bipolar cells is passed to ganglion cells in the retina. Bipolar cells receive input from photoreceptors in the outer plexiform layer and then relay signals onward to ganglion cells, with amacrine cells helping shape the signal, within the inner plexiform layer. That inner plexiform layer is where the synapses between bipolar cells and ganglion cells (and their interneuronal partners) occur. The other layers serve different stages of the pathway: the outer plexiform layer connects photoreceptors to bipolar and horizontal cells; the outer nuclear layer contains photoreceptor cell bodies; the inner nuclear layer contains the cell bodies of bipolar, amacrine, and horizontal cells. The inner plexiform layer is thus the site of bipolar-to-ganglion communication, making it the correct choice.