High concentration of cholecystokinin neurons in the newborn human entorhinal cortex

Numerous cholecystokinin (CCK)-immunoreactive cells are detected in the newborn human entorhinal cortex. They are located essentially in layer II and in the superficial part of layer III. Their shape and size indicate that they are interneurons. Most of them are vertically oriented and have beaded processes reaching layer I and the deep part of layer III. The cell type most frequently observed are bipolar cells with an ovoid cell body measuring 8-10 microns across and 15 microns in length. No CCK immunoreactivity is seen in the large stellate and pyramidal cells.