State-dependent activity dynamics of hypothalamic stress effector neurons
- Graduate Program in Neuroscience, Western University, Canada
- Department of Mathematics, Western University, Canada
- Brain and Mind Institute, Western University, Canada
- Department of Anatomy and Cell Biology, Schulich School of Medicine and Dentistry, Western University, Canada
- Robarts Research Institute, Western University, Canada
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, Western University, Canada
Figures
Figure 1
Optogenetic identification of CRHPVN neuron single-unit.
(A) Electrode tract (purple), TdTomato-expressing CRHPVN neurons (red) and ChR2-EYFP (green) expression. (B) An example for an isolated single-unit (blue) that also responded to light (cyan). (C) …
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Figure 1—source data 1
Optogenetic identification of CRHPVN neuron single-unit.
- https://cdn.elifesciences.org/articles/76832/elife-76832-fig1-data1-v2.xlsx
Figure 2 with 1 supplement
CRHPVN neurons fire in rhythmic bursts and single spikes.
(A) Two distinct spike patterns in a representative single-unit (top: single spikes; bottom: bursts indicated by arrow). (B) Interspike interval (ISI) distribution for the representative single-unit …
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Figure 2—source data 1
CRHPVN neurons fire in rhythmic bursts and single spikes.
- https://cdn.elifesciences.org/articles/76832/elife-76832-fig2-data1-v2.xlsx
Figure 2—figure supplement 1
Interspike interval (ISI) histograms for all CRHPVN units.
Burst rate (BR) is indicated on the top-right corner of individual histograms. Unit 18 and 30 did not fire bursts and are shown in gray.
Figure 3 with 1 supplement
CRHPVN neurons are constrained to low activity during rhythmic bursting.
(A) Peristimulus time histogram (PSTH) for a representative single-unit responding to sciatic nerve stimulation (1.5 mA, 0.5 ms × 5 pulses at 20 Hz, red line). (B–D) Raster plots for the unit shown …
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Figure 3—source data 1
CRHPVN neurons are constrained to low activity during rhythmic bursting.
- https://cdn.elifesciences.org/articles/76832/elife-76832-fig3-data1-v2.xlsx
Figure 3—figure supplement 1
Firing pattern changes persist longer with higher intensity nerve stimulations.
Raster plots of a representative single unit responding to different intensities of sciatic nerve stimulations. (A–C) 0.5 mA, (D–F) 1.0 mA, (G–I) 1.5 mA, and (J–L) 2.0 mA. Raster plots for all …
Figure 4
Prolonged silent periods precede burst firing.
(A) Preceding and proceeding interspike interval (ISI) plotted for individual spikes recorded from a representative single-unit. Blue rectangle indicates spikes with proceeding ISI <6 ms. Red …
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Figure 4—source data 1
Prolonged silent periods precede burst firin.
- https://cdn.elifesciences.org/articles/76832/elife-76832-fig4-data1-v2.xlsx
Figure 5 with 1 supplement
Recurrent inhibitory circuits generate burst firing and gate firing response to excitatory inputs in CRHPVN neurons.
(A) CRH model neuron in silico (black) fitted to current-clamp recordings of CRHPVN neurons ex vivo (red). (B) F-I curves for in silico (black) and ex vivo (red) neurons. (C) Network model diagram. …
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Figure 5—source data 1
Recurrent inhibitory circuits generate burst firing and gate firing response to excitatory inputs in CRHPVN neurons.
- https://cdn.elifesciences.org/articles/76832/elife-76832-fig5-data1-v2.xlsx
Figure 5—figure supplement 1
The temporal relationship between network and intrinsic properties with burst firing.
(A) Overlay of simulated membrane voltage (Vm; red) of representative traces of burst firing from model neurons (nneurons = 5; nbursts = 10). Note that spikes are truncated to 0 mV in this example. …
Figure 6
Recurrent inhibitory circuits underlie burst firing.
(A) Diagram of ‘network clamp’ experiment. (B–D) Time course of interspike interval (ISI) for a representative model CRH neurons (B), a biological CRHPVN neuron injected with network current (C) and …
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Figure 6—source data 1
Recurrent inhibitory circuits underlie burst firing.
- https://cdn.elifesciences.org/articles/76832/elife-76832-fig6-data1-v2.xlsx
Tables
Table 1
Parameters for spiking network model.
| Neuron parameters | Mean | S | Synapse parameters | Value |
|---|---|---|---|---|
| Number of neurons | 1000 | Ee (mV) | 0 | |
| Number of CRH neurons | 500 | Ei (mV) | –80 | |
| Number of GABA neurons | 500 | τe (ms) | 12.5 | |
| Capacitance (pF) | 22.0 | 2.6 | τCRH (ms) | 232.6 |
| τm (ms) | 26.0 | 2.5 | τi (ms) | 20.4 |
| gL (nS) | 0.9 | 0.19 | we (nS) | 3.9 |
| ∆T (mV) | 12.1 | 2.0 | wCRH (nS) | 0.005 |
| EL (mV) | –67.9 | 2.9 | wi (nS) | 3.3 |
| VT (mV) | –47.2 | 6.5 | τbr (s) | 40 |
| VR (mV) | –58.8 | 2.5 | τp (s) | 80 |
| τw (ms) | 98.2 | 54.3 | ||
| a (nS) | 0.082 | 0.13 | ||
| b (pA) | 17.9 | 9.8 |
