TY - JOUR
T1 - Fractal features of dark, maintained, and driven neural discharges in the cat visual system
AU - Lowen, Steven B.
AU - Ozaki, Tsuyoshi
AU - Kaplan, Ehud
AU - Saleh, Bahaa E.A.
AU - Teich, Malvin C.
N1 - Funding Information:
This work was supported by the U.S. Office of Naval Research under Grants N00014-92-J-1251 and N0014-93-12079, by the National Institute for Mental Health under Grant MH5066, by the National Eye Institute under Grants EY4888 and EY11276, by the Whitaker Foundation under Grant RG-96-0411, and by the National Science Foundation. E. Kaplan is Jules and Doris Stein Research-to-Prevent-Blindness Professor at Mt. Sinai School of Medicine.
PY - 2001
Y1 - 2001
N2 - We employ a number of statistical measures to characterize neural discharge activity in cat retinal ganglion cells (RGCs) and in their target lateral geniculate nucleus (LGN) neurons under various stimulus conditions, and we develop a new measure to examine correlations in fractal activity between spike-train pairs. In the absence of stimulation (i.e., in the dark), RGC and LGN discharges exhibit similar properties. The presentation of a constant, uniform luminance to the eye reduces the fractal fluctuations in the RGC maintained discharge but enhances them in the target LGN discharge, so that neural activities in the pair cease to be mirror images of each other. A drifting-grating stimulus yields RGC and LGN driven spike trains similar in character to those observed in the maintained discharge, with two notable distinctions: action potentials are reorganized along the time axis so that they occur only during certain phases of the stimulus waveform, and fractal activity is suppressed. Under both uniform-luminance and drifting-grating stimulus conditions (but not in the dark), the discharges of pairs of LGN cells are highly correlated over long time scales; in contrast discharges of RGCs are nearly uncorrelated with each other. This indicates that action-potential activity at the LGN is subject to a common fractal modulation to which the RGCs are not subjected.
AB - We employ a number of statistical measures to characterize neural discharge activity in cat retinal ganglion cells (RGCs) and in their target lateral geniculate nucleus (LGN) neurons under various stimulus conditions, and we develop a new measure to examine correlations in fractal activity between spike-train pairs. In the absence of stimulation (i.e., in the dark), RGC and LGN discharges exhibit similar properties. The presentation of a constant, uniform luminance to the eye reduces the fractal fluctuations in the RGC maintained discharge but enhances them in the target LGN discharge, so that neural activities in the pair cease to be mirror images of each other. A drifting-grating stimulus yields RGC and LGN driven spike trains similar in character to those observed in the maintained discharge, with two notable distinctions: action potentials are reorganized along the time axis so that they occur only during certain phases of the stimulus waveform, and fractal activity is suppressed. Under both uniform-luminance and drifting-grating stimulus conditions (but not in the dark), the discharges of pairs of LGN cells are highly correlated over long time scales; in contrast discharges of RGCs are nearly uncorrelated with each other. This indicates that action-potential activity at the LGN is subject to a common fractal modulation to which the RGCs are not subjected.
UR - http://www.scopus.com/inward/record.url?scp=0034847401&partnerID=8YFLogxK
U2 - 10.1006/meth.2001.1207
DO - 10.1006/meth.2001.1207
M3 - Article
AN - SCOPUS:0034847401
SN - 1046-2023
VL - 24
SP - 377
EP - 394
JO - Methods
JF - Methods
IS - 4
ER -