Immunohistochemical localization of substance P in anencephalic human fetus spinal cord

The distribution of substance P (SP) in human anencephalic fetus spinal cord has been studied with the indirect immunofluorescence technique. The SP-like immunoreactivity was detected within plexuses of fibres localized in the superficial layers of the dorsal grey including the marginal zone and substantia gelatinosa, and also the dorsal funicular grey. The other spinal cord areas were devoid of SP-like immunoreactivity. Comparison with normal fetus spinal cord reveals that in both normal and anencephalic fetuses the dorsal SP-patterns are comparable. This study indicates that in human fetus spinal cord most of the SP-fibres dorsally localized, occur even if the brain itself does not develop.