Which layer contains the synapses between photoreceptors and bipolar cells?

Which layer contains the synapses between photoreceptors and bipolar cells?

• A. Inner Plexiform Layer (IPL)
• B. Outer Plexiform Layer (OPL)
• C. Inner Nuclear Layer (INL)
• D. Nerve Fiber Layer (NFL)

Answer: (B)

The synapses between photoreceptors and bipolar cells are in the outer plexiform layer. This layer sits between the photoreceptor cell bodies (in the outer nuclear layer) and the inner nuclear layer, and it is where photoreceptor terminals form connections with the dendrites of bipolar cells (and horizontal cells). The inner plexiform layer, by contrast, is where bipolar cells connect to ganglion and amacrine cells. The inner nuclear layer contains the cell bodies of bipolar, horizontal, and amacrine cells, and the nerve fiber layer carries the axons of ganglion cells. So the place where the first synapse in the visual pathway from photoreceptors to bipolar cells occurs is the outer plexiform layer.

The synapses between photoreceptors and bipolar cells are in the outer plexiform layer. This layer sits between the photoreceptor cell bodies (in the outer nuclear layer) and the inner nuclear layer, and it is where photoreceptor terminals form connections with the dendrites of bipolar cells (and horizontal cells). The inner plexiform layer, by contrast, is where bipolar cells connect to ganglion and amacrine cells. The inner nuclear layer contains the cell bodies of bipolar, horizontal, and amacrine cells, and the nerve fiber layer carries the axons of ganglion cells. So the place where the first synapse in the visual pathway from photoreceptors to bipolar cells occurs is the outer plexiform layer.