Cajal–Retzius cell

Cajal–Retzius cells (CR cells) (also known as horizontal cells of Cajal) are a heterogeneous population of morphologically and molecularly distinct reelin-producing cells. They are found in the marginal zone/layer I of the developing cerebral cortex and in the immature hippocampus of different species and at different times during embryogenesis and postnatal life.

These cells were discovered by two scientists, Santiago Ramón y Cajal and Gustaf Retzius, at two different times and in different species. They are originated in the developing brain in multiple sites within the neocortex and hippocampus. From there, Cajal–Retzius cells migrate through the marginal zone, originating the layer I of the cortex.

CR cells are involved in the correct organization of the developing brain, and there are several studies that implicate them in neurodevelopmental disorders, including schizophrenia, bipolar disorder, autism, lissencephaly and temporal lobe epilepsy.