Correlation between the durations of refractory period and intrinsic optical signal of retinal spreading depression during temperature variations

• Published in: Experimental brain research Vol. 161; no. 2; pp. 201 - 208
• Main Authors: WEIMER, Marc S, HANKE, Wolfgang
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01-02-2005; Springer Nature B.V
• Subjects: Algorithms; Animals; Biological and medical sciences; Chickens - physiology; Cortical Spreading Depression - physiology; Electric Stimulation; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Male; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Photic Stimulation; Refractory Period, Electrophysiological - physiology; Retina - physiology; Temperature; Vertebrates: nervous system and sense organs; Temperature; Central nervous system; Electrophysiology; Retina; Eye; Depolarization; Visual system; Vertebrata; Retinal spreading depression (rSD); Animal; Refractory period; Chicken; Intrinsic optical signal (IOS); Membrane potential; Aves; Spreading depression; Room temperature
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-004-2060-5

Spreading depression (SD) is a neurophysiological phenomenon which occurs in the grey substance of the central nervous system. SD is characterised by a wave-like spread of depressed neuronal activity, by large ion shifts between intra- and extracellular space, by cellular depolarization, and by altered optical properties of the tissue giving rise to an intrinsic optical signal (IOS). In the shadow of SD further waves are difficult to trigger and such waves spread at lower velocity than usual. In this paper we examine the temperature dependence of the duration of this recovery (refractory) period and the temperature dependence of the duration of the IOS in the chicken retina. It is shown that these SD accompanying events are strongly dependent on temperature and that they are likely to depend on the metabolic rate in the tissue. The observed correlation of the duration of the IOS with the duration of the refractory period suggests that the IOS is a good indicator for the duration of the tissue recovery. Such a correlation would be of great value to the experimentalist who must know about the duration of the refractory period: while the latter is laborious to determine, recording the IOS is convenient.