Neuronal Activity in the Subthalamic Cerebrovasodilator Area under Partial-Gravity Conditions in Rats

Life

Jorge L. Zeredo¹  Kazuo Toda² 

[1] Graduate School, Tokyo Medical and Dental University, Tokyo 113-8549, Japan;Graduate School, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan; E-Mail:

关键词: parabolic flight;    gravity;    threshold;    electrophysiology;    brain;    subthalamic cerebrovasodilator area;    cerebral blood flow;    partial gravity;    intracranial EEG;    rats;   

DOI  :  10.3390/life4010107

来源: mdpi

【 摘 要 】

The reduced-gravity environment in space is known to cause an upward shift in body fluids and thus require cardiovascular adaptations in astronauts. In this study, we recorded in rats the neuronal activity in the subthalamic cerebrovasodilator area (SVA), a key area that controls cerebral blood flow (CBF), in response to partial gravity. “Partial gravity” is the term that defines the reduced-gravity levels between 1 g (the unit gravity acceleration on Earth) and 0 g (complete weightlessness in space). Neuronal activity was recorded telemetrically through chronically implanted microelectrodes in freely moving rats. Graded levels of partial gravity from 0.4 g to 0.01 g were generated by customized parabolic-flight maneuvers. Electrophysiological signals in each partial-gravity phase were compared to those of the preceding 1 g level-flight. As a result, SVA neuronal activity was significantly inhibited by the partial-gravity levels of 0.15 g and lower, but not by 0.2 g and higher. Gravity levels between 0.2–0.15 g could represent a critical threshold for the inhibition of neurons in the rat SVA. The lunar gravity (0.16 g) might thus trigger neurogenic mechanisms of CBF control. This is the first study to examine brain electrophysiology with partial gravity as an experimental parameter.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.