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Frequency Responses of Rat Retinal Ganglion Cells.

Hadjinicolaou AE, Cloherty SL, Hung YS, Kameneva T, Ibbotson MR - PLoS ONE (2016)

Bottom Line: The least responsive cells were the B2 and C3 types (peaks: 2-5 Hz, cutoffs: 8-11 Hz).We found no difference between cells stratifying in the inner and outer IPL (i.e., ON and OFF cells) or between cells with large and small somas or dendritic fields.Intrinsic physiological properties (input resistance, spike width and sag) had little impact on frequency response at low frequencies, but account for 30-40% of response variability at frequencies >30 Hz.

View Article: PubMed Central - PubMed

Affiliation: National Vision Research Institute, Australian College of Optometry, Carlton, Victoria, Australia.

ABSTRACT
There are 15-20 different types of retinal ganglion cells (RGC) in the mammalian retina, each encoding different aspects of the visual scene. The mechanism by which post-synaptic signals from the retinal network generate spikes is determined by each cell's intrinsic electrical properties. Here we investigate the frequency responses of morphologically identified rat RGCs using intracellular injection of sinusoidal current waveforms, to assess their intrinsic capabilities with minimal contributions from the retinal network. Recorded cells were classified according to their morphological characteristics (A, B, C or D-type) and their stratification (inner (i), outer (o) or bistratified) in the inner plexiform layer (IPL). Most cell types had low- or band-pass frequency responses. A2, C1 and C4o cells were band-pass with peaks of 15-30 Hz and low-pass cutoffs above 56 Hz (A2 cells) and ~42 Hz (C1 and C4o cells). A1 and C2i/o cells were low-pass with peaks of 10-15 Hz (cutoffs 19-25 Hz). Bistratified D1 and D2 cells were also low-pass with peaks of 5-10 Hz (cutoffs ~16 Hz). The least responsive cells were the B2 and C3 types (peaks: 2-5 Hz, cutoffs: 8-11 Hz). We found no difference between cells stratifying in the inner and outer IPL (i.e., ON and OFF cells) or between cells with large and small somas or dendritic fields. Intrinsic physiological properties (input resistance, spike width and sag) had little impact on frequency response at low frequencies, but account for 30-40% of response variability at frequencies >30 Hz.

No MeSH data available.


Related in: MedlinePlus

The effect of dendritic field size on the frequency response of retinal ganglion cells.Panels (A–D) show the mean frequency response of A2, C2, D1 and D2 RGC types. Within each RGC type, cells are grouped and their frequency responses averaged according to their dendritic field diameter. Within each RGC type, cells with the largest dendritic fields are shown in black and those with the smallest dendritic fields are shown in grey. For comparison, the frequency response, averaged over all cells of a given type, irrespective of dendritic field size, is shown by the dashed line. Black dots indicate statistically significant differences between large-field and small-field RGC responses (t-tests, p < 0.05). Panels (E–H) show distributions of dendritic field diameter for each of the A2, C2, D1 and D2 RGC types, respectively.
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pone.0157676.g007: The effect of dendritic field size on the frequency response of retinal ganglion cells.Panels (A–D) show the mean frequency response of A2, C2, D1 and D2 RGC types. Within each RGC type, cells are grouped and their frequency responses averaged according to their dendritic field diameter. Within each RGC type, cells with the largest dendritic fields are shown in black and those with the smallest dendritic fields are shown in grey. For comparison, the frequency response, averaged over all cells of a given type, irrespective of dendritic field size, is shown by the dashed line. Black dots indicate statistically significant differences between large-field and small-field RGC responses (t-tests, p < 0.05). Panels (E–H) show distributions of dendritic field diameter for each of the A2, C2, D1 and D2 RGC types, respectively.

Mentions: The effect of dendritic field size was found to vary with cell type. Fig 7A–7D show frequency responses for cells with large and small dendritic field diameters within each morphological cell type. Fig 7E–7H show distributions of dendritic field diameter for each cell type, indicating those cells in the upper and lower tails of each distribution designated as large (black bars; {A2, C2, D1, D2 dendritic field diameter} > {420, 370, 400, 500 μm}) and small (grey bars; {A2, C2, D1, D2 dendritic field diameter} < {370, 290, 300, 350 μm}) cells, respectively. A2 cells with large dendritic field diameters (>420 μm) were not as responsive to high frequency stimuli (p < 0.05 for frequencies ≥30 Hz) as those with small dendritic field diameters (<375 μm). Large-field D2 cells (>575 μm) were also outperformed by their small-field counterparts (<350 μm) when excited by low frequency stimuli (p < 0.049 for frequencies ≤5 Hz), although their average spiking response was greater when stimulated by higher frequencies (p > 0.282 for frequencies ≥20 Hz). Dendritic field size was also found to influence the mean spike probability (see Fig 4) in these two cell classes. In response to 60 Hz stimuli, the spiking probability for small-field A2 cells converged to ~17%, with large-field A2 cells converging to ~9%. Similarly, spiking probability in large- and small-field D2 cells reached ~8% and ~3%, respectively (data not shown). Large-field and small-field cells of the C2 and D1 classes had similar frequency responses (C2: p > 0.085; D1: p > 0.423).


Frequency Responses of Rat Retinal Ganglion Cells.

Hadjinicolaou AE, Cloherty SL, Hung YS, Kameneva T, Ibbotson MR - PLoS ONE (2016)

The effect of dendritic field size on the frequency response of retinal ganglion cells.Panels (A–D) show the mean frequency response of A2, C2, D1 and D2 RGC types. Within each RGC type, cells are grouped and their frequency responses averaged according to their dendritic field diameter. Within each RGC type, cells with the largest dendritic fields are shown in black and those with the smallest dendritic fields are shown in grey. For comparison, the frequency response, averaged over all cells of a given type, irrespective of dendritic field size, is shown by the dashed line. Black dots indicate statistically significant differences between large-field and small-field RGC responses (t-tests, p < 0.05). Panels (E–H) show distributions of dendritic field diameter for each of the A2, C2, D1 and D2 RGC types, respectively.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4920367&req=5

pone.0157676.g007: The effect of dendritic field size on the frequency response of retinal ganglion cells.Panels (A–D) show the mean frequency response of A2, C2, D1 and D2 RGC types. Within each RGC type, cells are grouped and their frequency responses averaged according to their dendritic field diameter. Within each RGC type, cells with the largest dendritic fields are shown in black and those with the smallest dendritic fields are shown in grey. For comparison, the frequency response, averaged over all cells of a given type, irrespective of dendritic field size, is shown by the dashed line. Black dots indicate statistically significant differences between large-field and small-field RGC responses (t-tests, p < 0.05). Panels (E–H) show distributions of dendritic field diameter for each of the A2, C2, D1 and D2 RGC types, respectively.
Mentions: The effect of dendritic field size was found to vary with cell type. Fig 7A–7D show frequency responses for cells with large and small dendritic field diameters within each morphological cell type. Fig 7E–7H show distributions of dendritic field diameter for each cell type, indicating those cells in the upper and lower tails of each distribution designated as large (black bars; {A2, C2, D1, D2 dendritic field diameter} > {420, 370, 400, 500 μm}) and small (grey bars; {A2, C2, D1, D2 dendritic field diameter} < {370, 290, 300, 350 μm}) cells, respectively. A2 cells with large dendritic field diameters (>420 μm) were not as responsive to high frequency stimuli (p < 0.05 for frequencies ≥30 Hz) as those with small dendritic field diameters (<375 μm). Large-field D2 cells (>575 μm) were also outperformed by their small-field counterparts (<350 μm) when excited by low frequency stimuli (p < 0.049 for frequencies ≤5 Hz), although their average spiking response was greater when stimulated by higher frequencies (p > 0.282 for frequencies ≥20 Hz). Dendritic field size was also found to influence the mean spike probability (see Fig 4) in these two cell classes. In response to 60 Hz stimuli, the spiking probability for small-field A2 cells converged to ~17%, with large-field A2 cells converging to ~9%. Similarly, spiking probability in large- and small-field D2 cells reached ~8% and ~3%, respectively (data not shown). Large-field and small-field cells of the C2 and D1 classes had similar frequency responses (C2: p > 0.085; D1: p > 0.423).

Bottom Line: The least responsive cells were the B2 and C3 types (peaks: 2-5 Hz, cutoffs: 8-11 Hz).We found no difference between cells stratifying in the inner and outer IPL (i.e., ON and OFF cells) or between cells with large and small somas or dendritic fields.Intrinsic physiological properties (input resistance, spike width and sag) had little impact on frequency response at low frequencies, but account for 30-40% of response variability at frequencies >30 Hz.

View Article: PubMed Central - PubMed

Affiliation: National Vision Research Institute, Australian College of Optometry, Carlton, Victoria, Australia.

ABSTRACT
There are 15-20 different types of retinal ganglion cells (RGC) in the mammalian retina, each encoding different aspects of the visual scene. The mechanism by which post-synaptic signals from the retinal network generate spikes is determined by each cell's intrinsic electrical properties. Here we investigate the frequency responses of morphologically identified rat RGCs using intracellular injection of sinusoidal current waveforms, to assess their intrinsic capabilities with minimal contributions from the retinal network. Recorded cells were classified according to their morphological characteristics (A, B, C or D-type) and their stratification (inner (i), outer (o) or bistratified) in the inner plexiform layer (IPL). Most cell types had low- or band-pass frequency responses. A2, C1 and C4o cells were band-pass with peaks of 15-30 Hz and low-pass cutoffs above 56 Hz (A2 cells) and ~42 Hz (C1 and C4o cells). A1 and C2i/o cells were low-pass with peaks of 10-15 Hz (cutoffs 19-25 Hz). Bistratified D1 and D2 cells were also low-pass with peaks of 5-10 Hz (cutoffs ~16 Hz). The least responsive cells were the B2 and C3 types (peaks: 2-5 Hz, cutoffs: 8-11 Hz). We found no difference between cells stratifying in the inner and outer IPL (i.e., ON and OFF cells) or between cells with large and small somas or dendritic fields. Intrinsic physiological properties (input resistance, spike width and sag) had little impact on frequency response at low frequencies, but account for 30-40% of response variability at frequencies >30 Hz.

No MeSH data available.


Related in: MedlinePlus