Journal of Neurophysiology, Vol 74, Issue 6 2548-2557, Copyright © 1995 by APS

ARTICLES

Transfer characteristics of lateral geniculate nucleus X neurons in the cat: effects of spatial frequency and contrast

H. Cheng, Y. M. Chino, E. L. Smith 3rd, J. Hamamoto and K. Yoshida
College of Optometry, University of Houston, Texas 77204-6052, USA.

1. The dependence of signal transfer in the lateral geniculate nucleus (LGN) on stimulus spatial frequency and contrast was investigated by comparing responses of individual X cells with their direct retinal inputs. 2. We used extracellular single-cell recording methods to isolate action potentials (LGN) and S potentials (SPs) from individual neurons in layers A and A1 of anesthetized and paralyzed cats. The stimuli were drifting sinusoidal gratings that were presented at each neuron's preferred orientation. The effects of stimulus spatial frequency and contrast on retinogeniculate signal transfer were determined by comparing the amplitude of the fundamental Fourier responses measured for a cell's action potentials (LGN) and its retinal input (SP) and calculating the transfer ratio (LGN amplitude/SP amplitude) for each stimulus condition. 3. In all units, the LGN response amplitude was lower than that of its retinal input regardless of stimulus spatial frequency. The mean transfer ratio measured at the peak spatial frequency for individual units was 0.56 +/- 0.03 (SE). For the majority of X LGN neurons, however, the efficiency of signal transfer varied considerably with stimulus spatial frequency. The average transfer ratio increased monotonically from 0.08 cycle/deg to near the high cutoff spatial frequency. 4. The effects of stimulus contrast on geniculate signal transfer were far more complex than previously reported and varied substantially between individual neurons. At low stimulus contrasts (< 10%), where all units exhibited linear response characteristics, only one third of our sample showed a monotonic decrease in transfer ratio with increasing stimulus contrast. The remaining two thirds either exhibited proportionately greater signal transfer for higher stimulus contrasts, or signal transfer remained relatively unchanged with increasing stimulus contrasts. When stimulus contrasts exceeded 10%, where response amplitude began to saturate, the transfer ratio was relatively constant in all units and independent of stimulus contrast. 5. Our results demonstrate that signal transfer from retina to visual cortex is regulated by LGN neurons in a stimulus-dependent manner, which appears to reflect the complex interactions between local membrane mechanisms and extraretinal inputs.

This article has been cited by other articles:

				T. G. Weyand Retinogeniculate Transmission in Wakefulness J Neurophysiol, August 1, 2007; 98(2): 769 - 785. [Abstract] [Full Text] [PDF]

				S. E. Palmer and K. D. Miller Effects of Inhibitory Gain and Conductance Fluctuations in a Simple Model for Contrast-Invariant Orientation Tuning in Cat V1 J Neurophysiol, July 1, 2007; 98(1): 63 - 78. [Abstract] [Full Text] [PDF]

				I. M. Andolina, H. E. Jones, W. Wang, and A. M. Sillito Corticothalamic feedback enhances stimulus response precision in the visual system PNAS, January 30, 2007; 104(5): 1685 - 1690. [Abstract] [Full Text] [PDF]

				V. Bonin, V. Mante, and M. Carandini The statistical computation underlying contrast gain control. J. Neurosci., June 7, 2006; 26(23): 6346 - 6353. [Abstract] [Full Text] [PDF]

				V. Bonin, V. Mante, and M. Carandini The Suppressive Field of Neurons in Lateral Geniculate Nucleus J. Neurosci., November 23, 2005; 25(47): 10844 - 10856. [Abstract] [Full Text] [PDF]

				M. Carandini, J. B. Demb, V. Mante, D. J. Tolhurst, Y. Dan, B. A. Olshausen, J. L. Gallant, and N. C. Rust Do We Know What the Early Visual System Does? J. Neurosci., November 16, 2005; 25(46): 10577 - 10597. [Abstract] [Full Text] [PDF]

				T. Z. Lauritzen and K. D. Miller Different Roles for Simple-Cell and Complex-Cell Inhibition in V1 J. Neurosci., November 12, 2003; 23(32): 10201 - 10213. [Abstract] [Full Text] [PDF]

				T. W. Troyer, A. E. Krukowski, and K. D. Miller LGN Input to Simple Cells and Contrast-Invariant Orientation Tuning: An Analysis J Neurophysiol, June 1, 2002; 87(6): 2741 - 2752. [Abstract] [Full Text] [PDF]

				T. Wennekers Orientation Tuning Properties of Simple Cells in Area V1 Derived from an Approximate Analysis of Nonlinear Neural Field Models Neural Comput., August 1, 2001; 13(8): 1721 - 1747. [Abstract] [Full Text]

				A. Kayser, N. J. Priebe, and K. D. Miller Contrast-Dependent Nonlinearities Arise Locally in a Model of Contrast-Invariant Orientation Tuning J Neurophysiol, May 1, 2001; 85(5): 2130 - 2149. [Abstract] [Full Text] [PDF]

				T. W. Troyer, A. E. Krukowski, N. J. Priebe, and K. D. Miller Contrast-Invariant Orientation Tuning in Cat Visual Cortex: Thalamocortical Input Tuning and Correlation-Based Intracortical Connectivity J. Neurosci., August 1, 1998; 18(15): 5908 - 5927. [Abstract] [Full Text] [PDF]

				F. S. Chance, S. B. Nelson, and L. F. Abbott Synaptic Depression and the Temporal Response Characteristics of V1 Cells J. Neurosci., June 15, 1998; 18(12): 4785 - 4799. [Abstract] [Full Text] [PDF]