Specific binding of [3H]-substance P to various regions of the human foetal brain

The existence of specific binding sites for the tachykinin Substance P was investigated in various regions of the central nervous system of a 28-week-old human foetus. Tritiated Substance P binds with high affinity to various amounts of binding sites in the limbic area of the brain, in the frontal, parietal and occipital cortices as well as in the cerebellum. The presence of these specific sites in the foetus is discussed in relation with the proposed neurotrophic role of Substance P.