Rexed's laminae and the acid phosphatase (FRAP)-band in the superficial dorsal horn of the neonatal rat spinal cord.
The pattern of Rexed's lamination and the situation of the FRAP-reactive band in the superficial dorsal horn were studied in transverse sections of the cervical cord of the rat from the day of birth (P0) to postnatal day P20. Laminae I, II and III increased moderately in thickness during this period, but the outer (IIo) and inner (IIi) zones of lamina II underwent opposite evolutions. Lamina IIi nearly doubled in thickness while lamina IIo decreased markedly. The FRAP-band was large on days P2 and P5 virtually covering lamina IIi, then shrank to a thinner strip in its dorsal part. It is suggested that lamina IIi growth is due to the massive arrival of FRAP-reactive thin primary axons followed by large afferents from deep layers occurring during the postnatal period, and the subsequent establishment of synaptic connections with the developing dendritic trees of dorsal horn cells.
D000135:Acid Phosphatase / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D007395:Interneurons / Q000201:enzymology; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000201:enzymology*
D000135:Acid Phosphatase