immediately deep to develops from develops from layer of neocortex cortical plate cortical layer III cortical layer IV NLXANAT:090810 internal granule cell layer of neocortex neuronames:2449 internal granular layer ... internal granular layer of neocortex layer 4 of neocortex UMLS:C1512872 UBERON:0005393 neocortical internal granule cell layer lamina granularis interna isocorticis [lamina iv] FMA:77811 MA:0000900 neocortex layer 4 EMAPA:35258 layer IV of neocortex cerebral cortex, layer 4 PBA:294021852 neocortex layer IV neocortex internal granule cell layer ABA:CTX4 neocortical layer IV NCIT:C32844 internal granular layer of isocortex [layer iv] Layer of neocortex lying deep to the external pyramidal cell layer defined cytoarchitecturally by the presence of numerous small cells. Relatively undeveloped in some mammals such as the tenrec.