The development of noradrenaline-, acetylcholinesterase-, neuropeptide Y- and vasoactive intestinal polypeptide-containing nerves in human cerebral arteries.

The development of cerebrovascular nerves containing noradrenaline (NA), acetylcholinesterase (AChE), neuropeptide Y (NPY) and vasoactive intestinal polypeptide (VIP) in the basilar artery was histochemically or immunohistochemically studied in human fetuses of various gestational ages. At the 12th week of gestation, nerve fibers containing NA and AChE appeared. Both types of nerve fibers consisted exclusively of the longitudinal nerve fibers (LNF) running along the basilar arteries. Subsequently, the circular nerve fibers (CNF) gradually increased and such development was then completed by the 20th week of gestation. NPY- and VIP-containing nerve fibers were detected in human fetal cerebral arteries in the 16th week of gestation, in the form of LNF. Subsequently, CNF gradually increased and development was completed by the 24th week of gestation. These results indicate that neuropeptide-containing nerve fibers, together with NA- and AChE-containing nerves, therefore contribute to the control of cerebral circulation in the later stages of embryogenesis in human cerebral arteries.