Neuronal regulation of the blood-brain barrier and neurovascular coupling.

To continuously process neural activity underlying sensation, movement and cognition, the CNS requires a homeostatic microenvironment that is not only enriched in nutrients to meet its high metabolic demands but that is also devoid of toxins that might harm the sensitive neural tissues. This highly regulated microenvironment is made possible by two unique features of CNS vasculature absent in the peripheral organs. First, the blood-blood barrier, which partitions the circulating blood from the CNS, acts as a gatekeeper to facilitate the selective trafficking of substances between the blood and the parenchyma.

Cortical ChAT neurons co-transmit acetylcholine and GABA in a target- and brain-region-specific manner.

The mouse cerebral cortex contains neurons that express choline acetyltransferase (ChAT) and are a potential local source of acetylcholine. However, the neurotransmitters released by cortical ChAT neurons and their synaptic connectivity are unknown. We show that the nearly all cortical ChAT neurons in mice are specialized VIP interneurons that release GABA strongly onto other inhibitory interneurons and acetylcholine sparsely onto layer 1 interneurons and other VIP/ChAT interneurons.

Caveolae in CNS arterioles mediate neurovascular coupling.

Proper brain function depends on neurovascular coupling: neural activity rapidly increases local blood flow to meet moment-to-moment changes in regional brain energy demand. Neurovascular coupling is the basis for functional brain imaging, and impaired neurovascular coupling is implicated in neurodegeneration. The underlying molecular and cellular mechanisms of neurovascular coupling remain poorly understood.

Blood-Brain Barrier Permeability Is Regulated by Lipid Transport-Dependent Suppression of Caveolae-Mediated Transcytosis.

The blood-brain barrier (BBB) provides a constant homeostatic brain environment that is essential for proper neural function. An unusually low rate of vesicular transport (transcytosis) has been identified as one of the two unique properties of CNS endothelial cells, relative to peripheral endothelial cells, that maintain the restrictive quality of the BBB. However, it is not known how this low rate of transcytosis is achieved.

Gradual Suppression of Transcytosis Governs Functional Blood-Retinal Barrier Formation.

Blood-central nervous system (CNS) barriers partition neural tissues from the blood, providing a homeostatic environment for proper neural function. The endothelial cells that form blood-CNS barriers have specialized tight junctions and low rates of transcytosis to limit the flux of substances between blood and CNS. However, the relative contributions of these properties to CNS barrier permeability are unknown.

The molecular constituents of the blood-brain barrier.

The blood-brain barrier (BBB) maintains the optimal microenvironment in the central nervous system (CNS) for proper brain function. The BBB comprises specialized CNS endothelial cells with fundamental molecular properties essential for the function and integrity of the BBB. The restrictive nature of the BBB hinders the delivery of therapeutics for many neurological disorders.