The development of cutaneous afferent pathways in fetal sheep: a structural and functional study

Abstract

In this study we have examined the functional and structural development of cutaneous afferent pathways in the fetal sheep hindlimb from 67 to 143 days of gestation. The earliest age at which extracellular discharges could be evoked in dorsal root ganglia and in dorsal horn cells by natural cutaneous stimulation was 75 days. The majority of cells responded to light stroking or indentation of the skin (low threshold) although some cells responded to intense squeezing (high threshold). With increasing gestational age, the majority of cells continued to respond to low threshold stimuli with cells responding to intense mechanical stimuli being recorded less frequently. Dorsal root ganglion cells..