Membranous structures in continuity with the nuclear envelope, in neuroblasts.
D000818:Animals; D002462:Cell Membrane; D002467:Cell Nucleus; D002642:Chick Embryo / Q000166:cytology; D005727:Ganglia, Spinal / Q000166:cytology*; D066298:In Vitro Techniques; D009474:Neurons / Q000196:embryology*