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Response of rabbit horizontal cells to a contrast reversal stimulus
198
Brain Research, 185 (1980) 198-202 © Elsevier/North-Holland Biomedical Press
Response of rabbit horizontal cells to a contrast reversal stimulus
D. L HAMASAKI, KYOJI TASAKI and HITOSHI SUZUKI Department of Physiology, Tohoku University, Sendai (Japan)
(Accepted November 8th, 1979) Key words: rabbit retina - - horizontal cells - - X- and Y-cells - - linear and non-linear spatial
summation
Retinal ganglion cells of cats 4, rhesus monkeys 2 and rabbits 1,s can be segregated into two types based on whether they demonstrate linear (X-cells) or non-linear (Ycells) spatial summation. The neural network which gives rise to these two types of response patterns has not been determined although it has been suggested that X-cells receive their main input from bipolar cells, while Y-cells receive their main input from amacrine cells 10. What role the horizontal cells might play in determining the linearity of spatial summation by the ganglion cells has been largely ignored, although it is known that current (hyperpolarizing and depolarizing) injected into horizontal cells can alter the firing pattern of ganglion cells of catfish 12, carp 13 and pikOL In order to detemine whether horizontal cells in the rabbit retina show linear or non-linear spatial summation, we recorded the responses elicited by a contrast reversal or alternating phase stimulus placed at different positions in the receptive field 7,9. In an earlier study s, we showed that with the same stimulus, rabbit ganglion cells can be segregated into linear X-cells and non-linear Y-cells. We wish to report here that at low stimulus intensity levels, horizontal cells show linear spatial summation and the response pattern resembles that of the X ganglion cells. At higher intensities, the horizontal cells demonstrate non-linear spatial summation. The non-linearity is seen as a doubling of the frequency which is characteristic of the Y ganglion cells in cats 9 and rabbits s. Experiments were conducted on the isolated eye-cup preparation (retina, choroid and sclera) of rabbits. The preparation was maintained in a Ringer-Locke incubating medium, and good responses were obtained up to 12 h after enucleation (for complete details, see ref. 8). Bevelled glass microelectrodes (40-80 M ~ after bevelling) were used to record intracellularly from horizontal cells 16. Responses were identified as arising from horizontal cells by the following criteria. First, the response * To whom reprint requests should be addressed at : William L. McKnight Vision Research Center, Department of Ophthalmology, University of Miami School of Medicine, 1638 N.W. 10th Avenue, Miami, Fla, 33136, U.S.A:
199 Eccentric
Null 5.5
. . . . .
---
5.0 4.5
4.0 3.5
~ ~
3 ~
.
-'--'-"---
0 _ ~stl m
~ .
~
~
.....
Fig. 1. Intracellular recordings from a horizontal cell. The responses recorded when the contrast reversal stimulus was placed eccentrically in the receptive field are shown in the left column, and the responses recorded when the stimulus was placed at the null position are shown in the right column. The diagrams at the bottom show the relationship between the stimulus and the receptive field of the horizontal cell. The numbers between the two columns represent the value of the neutral density filter used to attenuate the full intensity stimulus. The full intensity stimulus was 9.4 × 10-6 W/sq. cm. Calibration: 0.5 sec, 5 mV for all recordings except at eccentric 3.0 and 2.5 where calibration is 10 mV. was a hyperpolarizing potential change, the shape of which resembled the S-potentials recorded from the rabbit a and other species 6. Second, the responses were largest after a negative DC shift of 20-50 mV which usually occurred in several steps. Third, recordings were obtained at a mean depth of 113.1 # m (n ---- 13) from the vitreous surface of the retina. Fourth, the amplitude of the response was large and the response remained stable for up to 45 min. The contrast reversal stimulus was a 50° bipartite field which covered the entire retina. The intensity of each half of the stimulus changed sinusoidally (at 1.0 Hz), and was 180° out of phase with the intensity over the other half of the field. The intensity was altered from 9.4 × l0 -12 to 9.4 × l0 -6 W/cm 2, and the filters were used to eliminate the infra-red and UV portion of the spectrum. The contrast was kept constant at 90 % The responses recorded from a horizontal ceil are shown in Fig. 1. On the left are shown the responses elicited when the stimulus was positioned so that the whole receptive field was stimulated by one-half of the stimulus (see diagram at bottom). At low intensity levels (5.0-4.0), the shape of the response is approximately sinusoidal and resembles the shape of the stimulus (lower trace). At the higher intensity levels (3.5 -2.5), the shape of the response is no longer sinusoidal; the duration of the hyperpolarizing phase is significantly longer than the depolarizing phase. The shape of
200
13
A 4.0
4.0 s
t
i
m
.
~
~
_
:5.5 ---
I
5.0
:3.0
i
2.5
s
t
i
m
.
~
-
W
~
Fig. 2. Intracellular recordings from two horizontal cells. The numbers represent the neutral density filter used to attenuate the full intensity stimulus. Calibration: 0.5 sec, 5 mV for A and 2.5 mV for B. A: responses elicited from a horizontal cell by a square pulse of light of different stimulus intensities. Same cell as shown in Fig. 1. B" responses recorded from a different horizontal cell when the stimulus was placed symmetrically on opposite sides of the null position. Responses are shown for two different stimulus intensities. the responses elicited by the higher intensities closely resembles the responses recorded f r o m the horizontal cells of cats at high luminance levels 5. By displacing the stimulus across the receptive field in small steps, a critical position was found where there is no potential change synchronized with the change in the stimulus intensity (Fig. l, right column, 5.04.0). This position is then comparable to the null position of the X ganglion cells, and thus the horizontal cells under these stimulus conditions are X-like. At the higher stimulus intensities (3.5-2.5), the response of the horizontal cell is no longer null but there is a regular sinusoidal potential change. This response, however, differs from that obtained when the stimulus is placed eccentrically in the receptive field in that are two responses for each cycle of the stimulus, i.e. there is a doubling of the frequency. This doubling of the response is similar to that reported for the Y ganglion cells in cats 9 and rabbits s. The question then arises regarding the origin of the response, and why there is a doubling of the frequency at the higher stimulus intensities. Examination of the responses elicited from this same horizontal cell by a step input of light gives a clue to this question (Fig. 2A). At the lower stimulus intensities, the potential change at light on and off is symmetrical, i.e. the latency and rise time of the hyperpolarizing phase is comparable to that during the depolarizing phase. At the higher stimulus intensities, the response is no longer symmetrical; the hyperpolarizing phase at light on has a shorter latency and a faster 'rise time' than the depolarizing phase. These same characteristics have been reported for the horizontal cells in the cat 5,15. H o w this asymmetry results in a doubling of the response can be noted by examining Fig. 2B. The stimulus was placed at the null position so that the responses
201 elicited when both halves of the receptive field were stimulated were similar to that shown in Fig. lB. Then one half of the stimulus was blocked off by another polaroid, and the response elicited are shown as the uppermost traces in Fig. 2B (for I -- 4.0 and 3.0). The polaroid was then rotated by 90°, and the responses recorded from the other half of the receptive field are shown as the middle trace. The bottom trace shows the change of the stimulus intensity over one half of the field. At the lower stimulus intensity (4.0), the responses from each half of the receptive field are symmetrical and 180° out of phase, and the 'addition' of these two signals will result in no potential change. At the higher stimulus intensity level (3.0), the responses are no longer symmetrical, and the 'addition' of the response will not cancel but result in two responses for each cycle of the stimulus. (The larger responses from one half of the field, shown in the middle trace, indicate that the stimulus was not placed at the exact null position.) We have examined 9 horizontal cells under similar conditions, and in all cases the responses were similar to that described. The effect of stimulus intensity was not tested on the first 4 horizontal cells. How the X- and Y-ganglion cells in the rabbit's retina will be altered under identical changes in the stimulus intensities will be presented later. We wish to thank Dr. Joji Watanabe for his advice and assistance, and Mr. K. Kurama and Y. Takahashi for their help with the experiments. D.I.H. was supported by a grant from the Japan Society for the Promotion of Science as part of an exchange program with the National Eye Institute, U.S.A.
1 Caldwell, J. H. and Daw, N. W., New properties of rabbit retinal ganglion cells, J. PhysioL (Lond.), 276 (1978) 257-276. 2 DeMonasterio, F. M., Properties of linear and nonlinear ganglion cells in monkey retina, Ass. Res. Vision Ophthal., (1976). 3 DeMonasterio, F. M., Spectral interactions in horizontal and ganglion cells of the isolated and arterially-perfused rabbit retina, Brain Research, 150 (1978) 239-258. 4 Enroth-Cugell, C. and Robson, J. G., The contrast sensitivity of retinal ganglion cells of the cat, J. PhysioL (Lond.), 187 (1966) 517-522. 5 Foerster, M. H., van de Grind, W. A. and Gruesser, O.-J., Frequency transfer properties of three distinct types of cat horizontal cells, Exp. Brain Res., 29 (1977), 347-366. 6 Gouras, P., S-potentials. In M. G. F. Fuortes (Ed.), Handbook Sensory Physiology, VoL 1Ill/2 1972. 7 Hamasaki, D. I. and Sutija, V. G., Classification of cat retinal ganglion cells into X- and Y-cells with a contrast reversal stimulus, Exp. Brain Res., 35 (1979) 9-23. 8 Hamasaki, D. I., Tasaki, K. and Suzuki, H., Properties of X- and Y-cells in the rabbit retina, Jap. J. PhysioL, 29 (1979) 445-458. 9 Hochstein, S. and Shapley, R. M., Quantitative analysis of retinal ganglion cell classification, J. PhysioL (Lond.), 262 (1976) 237-264. 10 Hochstein, S. and Shapley, R. M., Linear and nonlinear spatial subunits in Y cat retinal ganglion cells, J. Physiol. (Lond.), 262 (1976) 265-284. 11 Maksimova, Y. M., Effect of intracellular polarization of horizontal cells on the activity of the ganglion cells in the retina of fish, Biophysics, 14 (1970) 570-577. 12 Naka, K.-I. and Nye, P. W., Role of horizontal cells in organization of the catfish retinal receptive field, J. NeurophysioL, 34 (1971) 785-801.
202 13 Negishi, K., Kato, S., Teranishi, T. and Hayashi, T., Effects of extrinsic horizontal cell polarization on spike discharges in the carp retina, Brain Research, 148 (1978) 95-104. 14 Rowe, M. H. and Stone, J., Naming ofneurones. Classification and naming of cat retinal ganglion cells, Brain Behav. Evol., 14 (1978) 185-216. 15 Steinberg, R. H., Rod-cone contributions to S-potentials from the cat retina, Vision Res., 9 (1969) 1319-1329. 16 Tasaki, K., Suzuki, H., Watanabe, S. and Narashige, Tohoku J. exp. Med., in press.
Brain Research, 185 (1980) 198-202 © Elsevier/North-Holland Biomedical Press
Response of rabbit horizontal cells to a contrast reversal stimulus
D. L HAMASAKI, KYOJI TASAKI and HITOSHI SUZUKI Department of Physiology, Tohoku University, Sendai (Japan)
(Accepted November 8th, 1979) Key words: rabbit retina - - horizontal cells - - X- and Y-cells - - linear and non-linear spatial
summation
Retinal ganglion cells of cats 4, rhesus monkeys 2 and rabbits 1,s can be segregated into two types based on whether they demonstrate linear (X-cells) or non-linear (Ycells) spatial summation. The neural network which gives rise to these two types of response patterns has not been determined although it has been suggested that X-cells receive their main input from bipolar cells, while Y-cells receive their main input from amacrine cells 10. What role the horizontal cells might play in determining the linearity of spatial summation by the ganglion cells has been largely ignored, although it is known that current (hyperpolarizing and depolarizing) injected into horizontal cells can alter the firing pattern of ganglion cells of catfish 12, carp 13 and pikOL In order to detemine whether horizontal cells in the rabbit retina show linear or non-linear spatial summation, we recorded the responses elicited by a contrast reversal or alternating phase stimulus placed at different positions in the receptive field 7,9. In an earlier study s, we showed that with the same stimulus, rabbit ganglion cells can be segregated into linear X-cells and non-linear Y-cells. We wish to report here that at low stimulus intensity levels, horizontal cells show linear spatial summation and the response pattern resembles that of the X ganglion cells. At higher intensities, the horizontal cells demonstrate non-linear spatial summation. The non-linearity is seen as a doubling of the frequency which is characteristic of the Y ganglion cells in cats 9 and rabbits s. Experiments were conducted on the isolated eye-cup preparation (retina, choroid and sclera) of rabbits. The preparation was maintained in a Ringer-Locke incubating medium, and good responses were obtained up to 12 h after enucleation (for complete details, see ref. 8). Bevelled glass microelectrodes (40-80 M ~ after bevelling) were used to record intracellularly from horizontal cells 16. Responses were identified as arising from horizontal cells by the following criteria. First, the response * To whom reprint requests should be addressed at : William L. McKnight Vision Research Center, Department of Ophthalmology, University of Miami School of Medicine, 1638 N.W. 10th Avenue, Miami, Fla, 33136, U.S.A:
199 Eccentric
Null 5.5
. . . . .
---
5.0 4.5
4.0 3.5
~ ~
3 ~
.
-'--'-"---
0 _ ~stl m
~ .
~
~
.....
Fig. 1. Intracellular recordings from a horizontal cell. The responses recorded when the contrast reversal stimulus was placed eccentrically in the receptive field are shown in the left column, and the responses recorded when the stimulus was placed at the null position are shown in the right column. The diagrams at the bottom show the relationship between the stimulus and the receptive field of the horizontal cell. The numbers between the two columns represent the value of the neutral density filter used to attenuate the full intensity stimulus. The full intensity stimulus was 9.4 × 10-6 W/sq. cm. Calibration: 0.5 sec, 5 mV for all recordings except at eccentric 3.0 and 2.5 where calibration is 10 mV. was a hyperpolarizing potential change, the shape of which resembled the S-potentials recorded from the rabbit a and other species 6. Second, the responses were largest after a negative DC shift of 20-50 mV which usually occurred in several steps. Third, recordings were obtained at a mean depth of 113.1 # m (n ---- 13) from the vitreous surface of the retina. Fourth, the amplitude of the response was large and the response remained stable for up to 45 min. The contrast reversal stimulus was a 50° bipartite field which covered the entire retina. The intensity of each half of the stimulus changed sinusoidally (at 1.0 Hz), and was 180° out of phase with the intensity over the other half of the field. The intensity was altered from 9.4 × l0 -12 to 9.4 × l0 -6 W/cm 2, and the filters were used to eliminate the infra-red and UV portion of the spectrum. The contrast was kept constant at 90 % The responses recorded from a horizontal ceil are shown in Fig. 1. On the left are shown the responses elicited when the stimulus was positioned so that the whole receptive field was stimulated by one-half of the stimulus (see diagram at bottom). At low intensity levels (5.0-4.0), the shape of the response is approximately sinusoidal and resembles the shape of the stimulus (lower trace). At the higher intensity levels (3.5 -2.5), the shape of the response is no longer sinusoidal; the duration of the hyperpolarizing phase is significantly longer than the depolarizing phase. The shape of
200
13
A 4.0
4.0 s
t
i
m
.
~
~
_
:5.5 ---
I
5.0
:3.0
i
2.5
s
t
i
m
.
~
-
W
~
Fig. 2. Intracellular recordings from two horizontal cells. The numbers represent the neutral density filter used to attenuate the full intensity stimulus. Calibration: 0.5 sec, 5 mV for A and 2.5 mV for B. A: responses elicited from a horizontal cell by a square pulse of light of different stimulus intensities. Same cell as shown in Fig. 1. B" responses recorded from a different horizontal cell when the stimulus was placed symmetrically on opposite sides of the null position. Responses are shown for two different stimulus intensities. the responses elicited by the higher intensities closely resembles the responses recorded f r o m the horizontal cells of cats at high luminance levels 5. By displacing the stimulus across the receptive field in small steps, a critical position was found where there is no potential change synchronized with the change in the stimulus intensity (Fig. l, right column, 5.04.0). This position is then comparable to the null position of the X ganglion cells, and thus the horizontal cells under these stimulus conditions are X-like. At the higher stimulus intensities (3.5-2.5), the response of the horizontal cell is no longer null but there is a regular sinusoidal potential change. This response, however, differs from that obtained when the stimulus is placed eccentrically in the receptive field in that are two responses for each cycle of the stimulus, i.e. there is a doubling of the frequency. This doubling of the response is similar to that reported for the Y ganglion cells in cats 9 and rabbits s. The question then arises regarding the origin of the response, and why there is a doubling of the frequency at the higher stimulus intensities. Examination of the responses elicited from this same horizontal cell by a step input of light gives a clue to this question (Fig. 2A). At the lower stimulus intensities, the potential change at light on and off is symmetrical, i.e. the latency and rise time of the hyperpolarizing phase is comparable to that during the depolarizing phase. At the higher stimulus intensities, the response is no longer symmetrical; the hyperpolarizing phase at light on has a shorter latency and a faster 'rise time' than the depolarizing phase. These same characteristics have been reported for the horizontal cells in the cat 5,15. H o w this asymmetry results in a doubling of the response can be noted by examining Fig. 2B. The stimulus was placed at the null position so that the responses
201 elicited when both halves of the receptive field were stimulated were similar to that shown in Fig. lB. Then one half of the stimulus was blocked off by another polaroid, and the response elicited are shown as the uppermost traces in Fig. 2B (for I -- 4.0 and 3.0). The polaroid was then rotated by 90°, and the responses recorded from the other half of the receptive field are shown as the middle trace. The bottom trace shows the change of the stimulus intensity over one half of the field. At the lower stimulus intensity (4.0), the responses from each half of the receptive field are symmetrical and 180° out of phase, and the 'addition' of these two signals will result in no potential change. At the higher stimulus intensity level (3.0), the responses are no longer symmetrical, and the 'addition' of the response will not cancel but result in two responses for each cycle of the stimulus. (The larger responses from one half of the field, shown in the middle trace, indicate that the stimulus was not placed at the exact null position.) We have examined 9 horizontal cells under similar conditions, and in all cases the responses were similar to that described. The effect of stimulus intensity was not tested on the first 4 horizontal cells. How the X- and Y-ganglion cells in the rabbit's retina will be altered under identical changes in the stimulus intensities will be presented later. We wish to thank Dr. Joji Watanabe for his advice and assistance, and Mr. K. Kurama and Y. Takahashi for their help with the experiments. D.I.H. was supported by a grant from the Japan Society for the Promotion of Science as part of an exchange program with the National Eye Institute, U.S.A.
1 Caldwell, J. H. and Daw, N. W., New properties of rabbit retinal ganglion cells, J. PhysioL (Lond.), 276 (1978) 257-276. 2 DeMonasterio, F. M., Properties of linear and nonlinear ganglion cells in monkey retina, Ass. Res. Vision Ophthal., (1976). 3 DeMonasterio, F. M., Spectral interactions in horizontal and ganglion cells of the isolated and arterially-perfused rabbit retina, Brain Research, 150 (1978) 239-258. 4 Enroth-Cugell, C. and Robson, J. G., The contrast sensitivity of retinal ganglion cells of the cat, J. PhysioL (Lond.), 187 (1966) 517-522. 5 Foerster, M. H., van de Grind, W. A. and Gruesser, O.-J., Frequency transfer properties of three distinct types of cat horizontal cells, Exp. Brain Res., 29 (1977), 347-366. 6 Gouras, P., S-potentials. In M. G. F. Fuortes (Ed.), Handbook Sensory Physiology, VoL 1Ill/2 1972. 7 Hamasaki, D. I. and Sutija, V. G., Classification of cat retinal ganglion cells into X- and Y-cells with a contrast reversal stimulus, Exp. Brain Res., 35 (1979) 9-23. 8 Hamasaki, D. I., Tasaki, K. and Suzuki, H., Properties of X- and Y-cells in the rabbit retina, Jap. J. PhysioL, 29 (1979) 445-458. 9 Hochstein, S. and Shapley, R. M., Quantitative analysis of retinal ganglion cell classification, J. PhysioL (Lond.), 262 (1976) 237-264. 10 Hochstein, S. and Shapley, R. M., Linear and nonlinear spatial subunits in Y cat retinal ganglion cells, J. Physiol. (Lond.), 262 (1976) 265-284. 11 Maksimova, Y. M., Effect of intracellular polarization of horizontal cells on the activity of the ganglion cells in the retina of fish, Biophysics, 14 (1970) 570-577. 12 Naka, K.-I. and Nye, P. W., Role of horizontal cells in organization of the catfish retinal receptive field, J. NeurophysioL, 34 (1971) 785-801.
202 13 Negishi, K., Kato, S., Teranishi, T. and Hayashi, T., Effects of extrinsic horizontal cell polarization on spike discharges in the carp retina, Brain Research, 148 (1978) 95-104. 14 Rowe, M. H. and Stone, J., Naming ofneurones. Classification and naming of cat retinal ganglion cells, Brain Behav. Evol., 14 (1978) 185-216. 15 Steinberg, R. H., Rod-cone contributions to S-potentials from the cat retina, Vision Res., 9 (1969) 1319-1329. 16 Tasaki, K., Suzuki, H., Watanabe, S. and Narashige, Tohoku J. exp. Med., in press.