Capillary innervation in the mammalian central nervous system: An electron microscopic demonstration

Abstract

Capillaries in the cat hypothalamus receive axon terminals which are comparable to neurovascular junctions in cerebral and systemic arteries and arterioles. The innervation of capillaries in the central nervous system may be derived from central neurons, in contrast to cerebral arterial vessels, which are supplied by the peripheral autonomic nervous system.

TNF-α knockout and minocycline treatment attenuates blood–brain barrier leakage in MPTP-treated mice

“…Since neuroinflammation including microglia activation and increased levels of proinflammatory cytokines including tumor necrosis factor-alpha (TNF-α) are present in patients with PD and in animal models of the disease (Aschner, 1998 ) it is quite possible that 6-OHDA-induced neuroinflammation was responsible for the breakdown in barrier integrity. However, neurons containing biogenic amines are found in close proximity to brain capillaries (Rennels and Nelson, 1975;DiCarlo, Jr. et al, 1984; Kapadia and de Lanerolle, 1984), endothelial cells express both noradrenergic and serotoninergic transporters (Wakayama et al, 2002) and receptors (Wakayama et al, 2002;Kobayashi et al, 1985), and stimulation of the locus coeruleus increases BBB permeability (Raichle et al, 1975) suggesting that neurotransmitters may regulate BBB function as well. The BBB leakage we observed in rats treated with 6-OHDA could be the result of neuroinflammation, DA neuron loss, or a combination of both.…”

Experimental and Morphological Study of the Innervation of Cerebral Blood Vessels

“…With the use of electron microscopy Rennels and Nelson demonstrated axon terminals close to capillary pericytes in the feline brain (21). However, even in the investigations which suggested that the central CA neuron system could possess important cerebro-vascular innervation, direct proof was lacking (1,2,14).…”

Do vasomotor nerves significantly regulate cerebral blood flow?

“…50 Although the function of these fibers is unknown, their presence has an added interest because of the recent findings of actin and myocin in these cells. 51 Clearly they could be important in vasomotor control at the capillary level and could affect the permeability of the blood-brain barrier.…”