Modeling apical and basal tree contribution to orientation selectivity in a mouse primary visual cortex layer 2/3 pyramidal cell
- Department of Biology, University of Crete, Greece
- IMBB, FORTH, Greece
- Department of Neurology, Brigham and Women’s Hospital and Jamaica Plain Veterans Administration Hospital, Harvard Medical School, United States
Figures
Figure 1 with 1 supplement
Dendritic properties of a L2/3 V1 neuron model.
(A) Graphical representation of the iterative paired-pulse protocol. Green dots represent allocated synapses. Synapses were activated only within the designated (red) dendritic segment, with all …
Figure 1—figure supplement 1
Visualization of dendritic non-linear properties.
(A) Expected vs Actual plot for all basal dendrites undergoing the I3P protocol for 1–200 synapses. Blue line represents the dendrite in Figure 1B (basal dendrite #0). (B) Same as A, but for all …
Figure 2 with 5 supplements
Neuronal orientation preference is robust and resists dendritic tuning disparity.
(A) Orientation tuning curve for the ‘biologically plausible’ model. (B) Example from a configuration of a model neuron set to a disparity of 40°. Right-side polar plots display the distribution of …
Figure 2—figure supplement 1
Comparing model output with two-photon imaging data.
Simultaneous recordings from basal dendritic segments and somata of L2/3 V1 pyramidal neurons were performed in anesthetized mice (spontaneous activity of 11 neurons from 2 mice, see Extended …
Figure 2—figure supplement 2
Properties of the GcaMP6s kernel.
(A) Illustration of the output of the kernel function for a single event (AP) occurring at t0 = 500ms. (marked as a red line). (B) Response intensity as a function of the number of events (APs) …
Figure 2—figure supplement 3
Waveforms of detected calcium fluorescence events.
Somatic waveforms in blue, basal dendritic waveforms in red. Spike onset detected at t=5 dt. (A) Waveforms from all detected events from both mice. (B) Waveforms from all detected events in mouse 1. …
Figure 2—figure supplement 4
Event-triggered averages of detected events and statistical testing of event pairs.
(A) Event-triggered averages for somatic (blue) and basal dendrite (red) events in mouse 1. (B) Event-triggered averages for somatic (blue) and basal dendrite (red) events in mouse 2. Note the …
Figure 2—figure supplement 5
Comparison of orientation tuning behavior seen in the model under control (blue) and apical dendrite ablation (red) configurations.
Note that the y-axis shows the normalized response (firing rate values divided by their corresponding maximum). Error bars: standard error of the mean.
Figure 3 with 1 supplement
Neuronal output relies disproportionately on apical sodium conductance.
(A) Diagram describing the ionic intervention protocol, with example traces on the right. Shaded areas on the traces denote the pre-spike (grey) and post-spike (red) intervention time windows. (B) …
Figure 3—figure supplement 1
Example traces showing the spatiotemporal evolution of somatodendritic voltage before, during and after the generation of a dendritic-sodium-mediated somatic spike, across different dendritic paths.
(A) Visualization of basal dendrites. Colors correspond to traces in panels B and C. (B) Voltage traces from the basal dendrites and soma (blue) around the occurrence of an apically driven somatic …
Figure 4 with 1 supplement
Orientation tuning critically depends on apical sodium conductance and ampa/nmda activity.
(A) Orientation tuning curves (left) and mean OSI values (right) for the experiment where stimulus-driven synapses are completely absent on either the apical (‘apical target’; red) or basal (‘basal …
Figure 4—figure supplement 1
Results from experiments similar to Figure 4C, only with a reduction in apical sodium conductance.
(A) Apical gNa decreased by 5%. Elimination of the apical sodium component results in total loss of tuning. (B) Apical gNa decreased by 10%. Unlike A, elimination of the apical or basal sodium …
Figure 5 with 1 supplement
Dendritic morphological and electrophysiological properties affect both local and somatic behavior.
(A) Left: Attenuation of a 20 mV dendritic EPSP (measured at the soma) as a function of dendritic segment length. Right: Comparison of length-normalized EPSP attenuation at the soma between apical …
Figure 5—figure supplement 1
Results from analyses similar to Figure 5.
Dendritic segments were stimulated with a number of synapses sufficient to elicit dendritic sodium spiking, and the attenuation at the soma was measured. (A) Somatic sodium spike attenuation as a …
Figure 6
Graphical representation of AP generation via bimodal Input coincidence in a L2/3 V1 pyramidal neuron model.
Action potential generation requires the spatiotemporal coincidence of apical sodium spikes with either basal sodium spikes or significant basal depolarizations, allowing the neuron to respond to …
Tables
Table 1
Outline of passive, active, and synaptic mechanisms present in the model neuron.
| Compartment type | Passive/active mechanisms | Synaptic mechanisms |
|---|---|---|
| Soma | Hodgkin/Huxley voltage-gated Na+ channels Hodgkin/Huxley voltage-gated K+ channels Muscarinic voltage-gated K+ channels A-Type voltage-gated K+ channels T-Type Ca++ channels High voltage activated (HVA) Ca++ channels Calcium-dependent K+ channels Active ATP Ca++ pumps | GABAA (background-driven) |
| Basal dendrites | AMPA (background-driven) NMDA (background-driven) GABAA (background-driven) AMPA (stimulus-driven) NMDA (stimulus-driven) GABAA (stimulus-driven) | |
| Apical dendrites |
Table 2
Outline of membrane mechanism conductances (not synaptic).
Reproduced from Park et al., 2019.
| Conductance (mS/cm2) | Soma | Apical | Basal |
|---|---|---|---|
| gNa | 0.505 | 0.303 | 0.303 |
| gKdr | 0.05 | 1.5*10–3 | 1.5*10–3 |
| gKm | 2.8*10–3 | 1.27*10–3 | 1.27*10–3 |
| gA | 5.4 | Diameter ≤0.8 μm: 108 Diameter >0.8 μm: 10.8 | Diameter ≤0.8 μm: 108 Diameter >0.8 μm: 10.8 |
| gT | 0.03 | x≤260 μm: 0.029*sin(0.009*x+0.88) x>260 μm: 0.012 | 0.03+6*10–5*x |
| gHVA | 0.05*10–3 | x≤260 μm: 0.049*10–3*sin(0.009*x+0.88) x>260 μm: 0.02*10–3 | 0.05*10–3+10–7*x |
| gKCa | 2.1*10–3 | 2.1*10–3 | 2.1*10–3 |
Table 3
Outline of model electrophysiological properties.
RMP: resting membrane potential, IR: Input Resistance measured at hyperpolarizing current (–0.04 nA), AP: action potential, AHP: after hyperpolarization measured at depolarizing current (0.16 nA), …
| Model | Cho et al., 2010 | |
|---|---|---|
| RMP, mV | –79 | –78.56 ± 1.34 |
| IR, MΩ | 123.6 | 125.2 ± 8.2 |
| τ, ms | 17.3 | 16 ± 0.7 |
| AP amplitude, mV | 66.1 | 67.8 ± 1.8 |
| AP threshold, mV | –41.8 | –37.7 ± 1.3 |
| AHP, mV | 17.9 | 13.3 ± 0.5 |
| P-T time, ms | 38.6 | 55.3 ± 2.7 |
| AP adaptation | 1.16 | 1.18 ± 0.02 |
Table 4
Outline of synaptic mechanism conductances and time constants.
Reproduced from Park et al., 2019.
| Conductance (nS) | τ1, ms | τ2, ms | |
|---|---|---|---|
| NMDA | 1.15 | 2 | 30 |
| AMPA | 0.84 | 0.1 | 2.5 |
| GABAA | 1.25 | 0.2 | 1.4 |
