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 cell types in the marginal zone/layer I of the developmental 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 (CR) cells migrate through the marginal zone, originating the layer I of the cortex.

As these cells are involved in the correct organization of the developing brain, there are several studies implicating CR cells in neurodevelopmental disorders, especially schizophrenia, bipolar disorder, autism, lissencephaly and temporal lobe epilepsy.