develops from intersegmental nerve root glial cell medial intersegmental nerve root glial cell fly_anatomy.ontology M-ISNG intersegmental glial cell 1 VFB:FBbt_00001305 The medial intersegmental nerve root glial cell corresponds to segment boundary cell (SBC) described by Goodman and Doe (1993) and ISPG1 described by Klambt and Goodman (1991) (Ito et al., 1995). FBbt:00001305 Intersegmental nerve glial cell that is located at the medial end of the anterior branch of the intersegmental nerve root, above the lateral neuropil. It contacts both the perineurium and the cortex/neuropil interface and its position is slightly lateral to the B-SPG. It sends a process laterally along the nerve root, showing a characteristic triangular morphology. It develops from the NB1-3 neuroblast (Beckervordersandforth et al., 2008). SBC ISG1 segment boundary cell neuroblast NB1-3 ectodermal derivative