Author: Li Z1,2, Dai J3,4
Affiliation: <sup>1</sup>Wuhan Institute for Neuroscience and Neuroengineering, South Central University for Nationalities, Wuhan, 430074, China.
<sup>2</sup>Department of Neurobiology, College of Life Sciences, South Central University for Nationalities, Wuhan, 430074, China.
<sup>3</sup>Wuhan Institute for Neuroscience and Neuroengineering, South Central University for Nationalities, Wuhan, 430074, China. jdai@mail.scuec.edu.cn.
<sup>4</sup>Department of Neurobiology, College of Life Sciences, South Central University for Nationalities, Wuhan, 430074, China. jdai@mail.scuec.edu.cn.
Conference/Journal: Neurosci Bull.
Date published: 2016 Jun
Other:
Volume ID: 32 , Issue ID: 3 , Pages: 246-52 , Special Notes: doi: 10.1007/s12264-016-0029-6. Epub 2016 Apr 8. , Word Count: 159
The discovery of dark noise in retinal photoreceptors resulted in a long-lasting controversy over its origin and the underlying mechanisms. Here, we used a novel ultra-weak biophoton imaging system (UBIS) to detect biophotonic activity (emission) under dark conditions in rat and bullfrog (Rana catesbeiana) retinas in vitro. We found a significant temperature-dependent increase in biophotonic activity that was completely blocked either by removing intracellular and extracellular Ca(2+) together or inhibiting phosphodiesterase 6. These findings suggest that the photon-like component of discrete dark noise may not be caused by a direct contribution of the thermal activation of rhodopsin, but rather by an indirect thermal induction of biophotonic activity, which then activates the retinal chromophore of rhodopsin. Therefore, this study suggests a possible solution regarding the thermal activation energy barrier for discrete dark noise, which has been debated for almost half a century.
KEYWORDS: Biophoton; Biophoton imaging; Ca2+; Phosphodiesterase 6; Rat and bullfrog retinas; Retinal dark noise
PMID: 27059222 DOI: 10.1007/s12264-016-0029-6