Substance P-immunoreactive astrocytes related to deep white matter and striatal blood vessels in human brain

Astrocytes immunoreactive for the vasodilator neuropeptide substance P are present adjacent to blood vessels which are contacted by their processes in restricted regions of the deep gray and white matter of the forebrains of human infants. Such astrocytes may play a non-neural role in mediating increases in cerebral blood flow in response to local metabolic changes.