Astrocyte morphology is confined by cortical functional boundaries in mammals ranging from mice to human

• Published in: eLife Vol. 5
• Main Authors: Eilam, Raya, Aharoni, Rina, Arnon, Ruth, Malach, Rafael
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 10.06.2016; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Animals; Astrocytes; Astrocytes - cytology; auditory cortex; Auditory Cortex - cytology; barrel fields; Blood flow; Boundaries; Capillaries; Cell Shape; Cerebral circulation; Cortex (auditory); Cortex (somatosensory); Cytochrome; functional architecture; Functional magnetic resonance imaging; Humans; Mice; Morphology; Neural circuitry; Neurons; Neuroscience; Neurosciences; Observations; Physiological aspects; Rats; somatosensory cortex; Species; striate cortex; Visual cortex; Visual Cortex - cytology; functional architecture; mouse; auditory cortex; rat; neuroscience; striate cortex; astrocytes; somatosensory cortex; barrel fields; human
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.15915

Cortical blood flow can be modulated by local activity across a range of species; from barrel-specific blood flow in the rodent somatosensory cortex to the human cortex, where BOLD-fMRI reveals numerous functional borders. However, it appears that the distribution of blood capillaries largely ignores these functional boundaries. Here we report that, by contrast, astrocytes, a major player in blood-flow control, show a striking morphological sensitivity to functional borders. Specifically, we show that astrocyte processes are structurally confined by barrel boundaries in the mouse, by the border of primary auditory cortex in the rat and by layers IIIa/b and Cytochrome Oxidase (CO)-blobs boundaries in the human primary visual cortex. Thus, astrocytes which are critical elements in neuro-hemodynamic coupling show a significant anatomical segregation along functional boundaries across different mammalian species. These results may open a new anatomical marker for delineating functional borders across species, including post-mortem human brains.