Pial arteries respond earlier than penetrating arterioles to neural activation in the somatosensory cortex in awake mice exposed to chronic hypoxia: An additional mechanism to proximal integration signaling?

Yuta Sekiguchi, Hiroyuki Takuwa, Hiroshi Kawaguchi, Takahiro Kikuchi, Eiji Okada, Iwao Kanno, Hiroshi Ito, Yutaka Tomita, Yoshiaki Itoh, Norihiro Suzuki, Ryo Sudo, Kazuo Tanishita, Kazuto Masamoto

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The pial and penetrating arteries have a crucial role in regulating cerebral blood flow (CBF) to meet neural demand in the cortex. Here, we examined the longitudinal effects of chronic hypoxia on the arterial diameter responses to single whisker stimulation in the awake mouse cortex, where activity-induced responses of CBF were gradually attenuated. The vasodilation responses to whisker stimulation under prehypoxia normal conditions were 8.1% and 12% relative to their baselines in the pial arteries and penetrating arterioles, respectively. After 3 weeks of hypoxia, however, these responses were significantly reduced to 5.5% and 4.1%, respectively. The CBF response, measured using laser-Doppler flowmetry (LDF), induced by the same whisker stimulation was also attenuated (14% to 2.6%). A close linear correlation was found for the responses between the penetrating arteriolar diameter and LDF, and their temporal dynamics. After 3 weeks of chronic hypoxia, the initiation of vasodilation in the penetrating arterioles was significantly extended, but the pial artery responses remained unchanged. These results show that vasodilation of the penetrating arterioles followed the pial artery responses, which are not explainable in terms of proximal integration signaling. The findings therefore indicate an additional mechanism for triggering pial artery dilation in the neurovascular coupling.

Original languageEnglish
Pages (from-to)1761-1770
Number of pages10
JournalJournal of Cerebral Blood Flow and Metabolism
Volume34
Issue number11
DOIs
Publication statusPublished - 2014 Jan 1

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Keywords

  • activity-induced vasodilation
  • cerebral blood flow regulation
  • laser scanning microscopy
  • microvascular plasticity
  • neurovascular coupling

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine

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