HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Barlow, H. B. Articles by Levick, W. R. Search for Related Content PubMed PubMed Citation Articles by Barlow, H. B. Articles by Levick, W. R.

1. The mean rate, impulse interval distribution, and pulse number distribution of the maintained discharge of ganglion cells in the retina of the cat have been studied after prolonged adaptation at different luminance levels.

2. From a state of complete dark adaptation up to a luminance of about 5 x 10^-3 cd/m² (viewed through a 7 mm² pupil) the mean rate of on-centre units increases. From darkness up to a somewhat higher luminance the mean rate of some off-centre units decreases, but others show little change.

3. Above 10^-2 cd/m² the mean rate ceases to show a regular relation with adaptation level. On units often decrease and then increase again at a higher level. Rhythmical fluctuations are common near 10^-2 cd/m², especially if the retina is not in first class condition. Mean rates above 70/sec and below 1/sec are very rare at any adaptation level.

4. Over the range where mean rate increases monotonically with adaptation level, it is shown that the surround of on-centre units does not inhibit and off responses cannot be elicited. When the monotonic increase is slowed or reversed it becomes possible to elicit responses from the surround. We suspect that the surround exerts a sustained, tonic, inhibiting effect at higher adaptation levels, thus holding down the maintained discharge.

5. There are rare units, forming less than 1% of those isolated, that show a regularly increasing frequency with increase of adaptation level above 10^-2 cd/m². These units have concentric `on' and `off' zones in their receptive fields, but the responses to rapidly changing stimuli are sluggish and they have an unusually regular maintained discharge. They have been tentatively called `luminance units'.

6. The impulse-interval and pulse-number distributions of on-centre units change predictably with adaptation level; the variance of the pulse number distribution is usually several times the mean at very low adaptation levels, but only a fraction of the mean at high levels. Off-centre units do not show predictable changes. Luminance units fire more regularly, and have narrower pulse-number and impulse interval distributions than other concentric units.

7. A simple model is proposed to account for the statistical characteristics of the maintained discharge of on-centre units.

This article has been cited by other articles:

				K. Y. Wong, F. A. Dunn, D. M. Graham, and D. M. Berson Synaptic influences on rat ganglion-cell photoreceptors J. Physiol., July 1, 2007; 582(1): 279 - 296. [Abstract] [Full Text] [PDF]

				D. J. Margolis and P. B. Detwiler Different Mechanisms Generate Maintained Activity in ON and OFF Retinal Ganglion Cells J. Neurosci., May 30, 2007; 27(22): 5994 - 6005. [Abstract] [Full Text] [PDF]

				T. Vladusich, M. P. Lucassen, and F. W. Cornelissen Do Cortical Neurons Process Luminance or Contrast to Encode Surface Properties? J Neurophysiol, April 1, 2006; 95(4): 2638 - 2649. [Abstract] [Full Text] [PDF]

				A. Vogel, R. M. Hennig, and B. Ronacher Increase of Neuronal Response Variability at Higher Processing Levels as Revealed by Simultaneous Recordings J Neurophysiol, June 1, 2005; 93(6): 3548 - 3559. [Abstract] [Full Text] [PDF]

				C. F. Vaquero, A. Pignatelli, G. J. Partida, and A. T. Ishida A Dopamine- and Protein Kinase A-Dependent Mechanism for Network Adaptation in Retinal Ganglion Cells J. Neurosci., November 1, 2001; 21(21): 8624 - 8635. [Abstract] [Full Text] [PDF]

				C. L. Passaglia, C. Enroth-Cugell, and J. B. Troy Effects of Remote Stimulation on the Mean Firing Rate of Cat Retinal Ganglion Cells J. Neurosci., August 1, 2001; 21(15): 5794 - 5803. [Abstract] [Full Text] [PDF]

				M. J. Chacron, A. Longtin, and L. Maler Negative Interspike Interval Correlations Increase the Neuronal Capacity for Encoding Time-Dependent Stimuli J. Neurosci., July 15, 2001; 21(14): 5328 - 5343. [Abstract] [Full Text] [PDF]

				R. Ratnam and M. E. Nelson Nonrenewal Statistics of Electrosensory Afferent Spike Trains: Implications for the Detection of Weak Sensory Signals J. Neurosci., September 1, 2000; 20(17): 6672 - 6683. [Abstract] [Full Text] [PDF]

				D. E. Nelson and J. S. Takahashi Integration and saturation within the circadian photic entrainment pathway of hamsters Am J Physiol Regulatory Integrative Comp Physiol, November 1, 1999; 277(5): R1351 - R1361. [Abstract] [Full Text] [PDF]

				E. D. Cohen Interactions of Inhibition and Excitation in the Light-Evoked Currents of X Type Retinal Ganglion Cells J Neurophysiol, December 1, 1998; 80(6): 2975 - 2990. [Abstract] [Full Text] [PDF]

				M. J. Berry, D. K. Warland, and M. Meister The structure and precision of retinal spike trains PNAS, May 13, 1997; 94(10): 5411 - 5416. [Abstract] [Full Text] [PDF]