Article Figures & Data
Figures
- Figure 1.
Morphological characteristics of M1 and M2 cells. A1, B1, Whole-mount retinas of M1 and M2 cells filled with Neurobiotin (green) and immunostained for ChAT (red), a cholinergic amacrine cell marker. A1, M1 cell with dendrites stratifying solely in sublamina a of the IPL. A2, Tracings of M1 cells to show dendritic morphology. B1, M2 cell with dendrites stratifying solely in the sublamina b of the IPL. B2, Tracings of M2 cells to show dendritic morphology. C, Dendritic field diameter and total dendritic length of M1 (red; n = 16) and M2 (black; n = 13) cells. Mean dendritic field diameter and total dendritic length of M1 (green) and M2 (blue) cells are shown. D, Soma diameter of M1 (red: n = 16) and M2 (black: n = 13) cells. Mean soma diameter of M1 (red bar) and M2 (black bar) cells. E, F, M1 (green) and M2 (magenta) dendrites of neighboring M1 (yellow arrow) and M2 (white arrow) cells filled with Neurobiotin. ChAT, Choline acetyl transferase, IPL, inner plexiform layer. Scale bars: 50 μm.
- Figure 2.
Intrinsic light responses of M1 and M2 cells in whole-mount Opn4-EGFP mouse retinas. All light responses recorded in the presence of synaptic blockers and TTX. A, Left, EGFP signal under epifluorescent illumination of M1 (gray arrow) and M2 (white arrow) cell targeted for dual whole-cell current-clamp recordings. Right, Responses in current-clamp mode of M1 (gray trace) and M2 (black trace) cells shown in left panel to a 30 s white light stimulus. B, Left, EGFP signal under epifluorescent illumination of M1 (gray arrow) and M2 (white arrow) cell targeted for dual whole-cell voltage-clamp recordings. Right, Responses in voltage-clamp mode of M1 (gray trace) and M2 (black trace) cells shown in the left panel to a 30 s white light stimulus. C, Maximum depolarization evoked by single 30 s white light stimulus measured in current-clamp mode of M1 (gray; n = 17) and M2 (black; n = 19) cells. Mean depolarization of M1 (gray bar) and M2 (black bar) cells. D, Maximum current evoked by single 30 s white light stimulus measured in voltage-clamp mode of M1 (gray; n = 13) and M2 (black; n = 19) cells. Mean maximum current of M1 (gray bar) and M2 (black bar) cells. E, Brightness (in AUs) of epifluorescence of EGFP signal for pairs containing one M1 and one M2 cell. F, Irradiance response curves for M1 (gray; IR50 ∼ 3.25 × 1012 photons · cm−2 · s−1) and M2 (black; IR50 ∼ 3.44 × 1013 photons · cm−2 · s−1) generated by stimulating cells with increasing intensities of a 5 s 480 nm light stimulus. G, Nucleated patch recordings were made in control solution from M2 cells (n = 5). H, I, Average of 5–7 light responses recorded from nucleated patches of two cells (cell 1, left panels; cell 2, right panels) in current-clamp mode to a fixed, bright 5 s (H) or 30 s (I) white light stimulus. J, Expanded view of first 1 s of 30 s light stimulation for cell 1 (left panel) and cell 2 (right panel). Scale bars: 50 μm. IR50, Irradiance yielding half-maximal response.
- Figure 3.
Responses of M1 and M2 cells to hyperpolarizing current pulses. Recordings were performed in the presence of synaptic blockers. A, B, Responses of M1 (A) and M2 (B) cells to 1 s hyperpolarizing current injection. Values to the right of the steps indicate the maximum current injection shown. C, RN and Vm of M1 (red; n = 23) and M2 (black; n = 25) cells. Mean RN and Vm shown for M1 (green bars) and M2 (blue bars) cells. D, Mean ± SE voltage response of M1 (red, n = 15) and M2 (black, n = 12) cells to hyperpolarizing current steps. Current injections were divided by capacitance of the cells to facilitate averaging (bin = 0.5 pA/pF). Points were fit with linear regression. RN, Input resistance; Vm, resting membrane potential.
- Figure 4.
Responses of M1 and M2 cells to depolarizing current pulses. Recordings were performed in the presence of synaptic blockers. A, B, Representative response of M1 (A) and M2 (B) cells to 1 s depolarizing current injection. Values to the right of the current steps indicate maximum current injection shown. C, Instantaneous frequency of the first interspike interval for M1 cell in A (gray) and M2 cell in B (black). D, Average firing rate for duration of 1 s depolarizing steps for M1 cell in A (gray) and M2 cell in B (black). E, Instantaneous frequency over time for M1 cell in A. F, Instantaneous frequency over time for M2 cell in B. G, Mean ± SE instantaneous frequency of the first interspike interval (circles) and mean ± SE firing rate (squares) during current injection for M1 (gray, n = 15) and M2 (black, n = 12) cells. Current injection for each cell was divided by its capacitance (bin = 0.5 pA/pF) to facilitate averaging.
Additional Files
Supplemental Data
Files in this Data Supplement:
- supplemental material - Supplemental Material
- supplemental material - Supplemental Figure 1
- supplemental material - Supplemental Figure 2
