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Modulation of a Single Neuron Has State-Dependent Actions on Circuit Dynamics(,.)

Gutierrez GJ, Marder E - eNeuro (2014)

Bottom Line: We determined the effects of varying ḡCa , ḡK , and ḡh on the frequency, amplitude, and duty cycle of a single neuron oscillator.For a different set of network parameters, circuit behavior varied with the maximal conductances of the hub neuron.This demonstrates that neuromodulation of a single target neuron may dramatically alter the performance of an entire network when the network is in one state, but have almost no effect when the circuit is in a different state.

View Article: PubMed Central - HTML - PubMed

Affiliation: Volen Center for Complex Systems and Biology Department, Brandeis University, Waltham, Massachusetts 02454.

ABSTRACT

When does neuromodulation of a single neuron influence the output of the entire network? We constructed a five-cell circuit in which a neuron is at the center of the circuit and the remaining neurons form two distinct oscillatory subnetworks. All neurons were modeled as modified Morris-Lecar models with a hyperpolarization-activated conductance (ḡh ) in addition to calcium (ḡCa ), potassium (ḡK ), and leak conductances. We determined the effects of varying ḡCa , ḡK , and ḡh on the frequency, amplitude, and duty cycle of a single neuron oscillator. The frequency of the single neuron was highest when the ḡK and ḡh conductances were high and ḡCa was moderate whereas, in the traditional Morris-Lecar model, the highest frequencies occur when both ḡK and ḡCa are high. We randomly sampled parameter space to find 143 hub oscillators with nearly identical frequencies but with disparate maximal conductance, duty cycles, and burst amplitudes, and then embedded each of these hub neurons into networks with different sets of synaptic parameters. For one set of network parameters, circuit behavior was virtually identical regardless of the underlying conductances of the hub neuron. For a different set of network parameters, circuit behavior varied with the maximal conductances of the hub neuron. This demonstrates that neuromodulation of a single target neuron may dramatically alter the performance of an entire network when the network is in one state, but have almost no effect when the circuit is in a different state.

No MeSH data available.


Related in: MedlinePlus

hn candidates and intrinsic properties. The hn candidates all have isolated frequencies within the range of 0.5717 ± 0.01 Hz. The set of 143 individual neurons spans ionic conductance space in a V-formation. A, hn candidate duty cycles spanned the range of 4.27% to 52.7%. B, The peak voltages are the mean supra-threshold oscillation peak voltages and these ranged from 0.7132 to 69.5211 mV. C, The first two panels are two-dimensional plots of duty cycles containing the same data as A. A histogram for hn candidate duty cycles (right); mean duty cycle is 21.33%, standard deviation 11.24. D, One-dimensional plots for peak voltages as function of individual hn conductances (left) make the correlations in B more apparent. These are further summarized in the middle plot showing the relationships between the three conductances and the peak voltages of the hn candidates with regression lines. Right, Histogram for hn candidate peak voltages; mean of peak voltages is 36.2955 mV, standard deviation 17.8493 mV.
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Figure 5: hn candidates and intrinsic properties. The hn candidates all have isolated frequencies within the range of 0.5717 ± 0.01 Hz. The set of 143 individual neurons spans ionic conductance space in a V-formation. A, hn candidate duty cycles spanned the range of 4.27% to 52.7%. B, The peak voltages are the mean supra-threshold oscillation peak voltages and these ranged from 0.7132 to 69.5211 mV. C, The first two panels are two-dimensional plots of duty cycles containing the same data as A. A histogram for hn candidate duty cycles (right); mean duty cycle is 21.33%, standard deviation 11.24. D, One-dimensional plots for peak voltages as function of individual hn conductances (left) make the correlations in B more apparent. These are further summarized in the middle plot showing the relationships between the three conductances and the peak voltages of the hn candidates with regression lines. Right, Histogram for hn candidate peak voltages; mean of peak voltages is 36.2955 mV, standard deviation 17.8493 mV.

Mentions: We created a population of model neurons with vastly ranging conductances and similar frequencies to examine the effects of modulation of the intrinsic properties of these centralized neurons on circuit output. Therefore, we generated 143 hub neuron candidates with frequencies of 0.5717 ± 0.01 Hz. Figure 5 shows their properties.


Modulation of a Single Neuron Has State-Dependent Actions on Circuit Dynamics(,.)

Gutierrez GJ, Marder E - eNeuro (2014)

hn candidates and intrinsic properties. The hn candidates all have isolated frequencies within the range of 0.5717 ± 0.01 Hz. The set of 143 individual neurons spans ionic conductance space in a V-formation. A, hn candidate duty cycles spanned the range of 4.27% to 52.7%. B, The peak voltages are the mean supra-threshold oscillation peak voltages and these ranged from 0.7132 to 69.5211 mV. C, The first two panels are two-dimensional plots of duty cycles containing the same data as A. A histogram for hn candidate duty cycles (right); mean duty cycle is 21.33%, standard deviation 11.24. D, One-dimensional plots for peak voltages as function of individual hn conductances (left) make the correlations in B more apparent. These are further summarized in the middle plot showing the relationships between the three conductances and the peak voltages of the hn candidates with regression lines. Right, Histogram for hn candidate peak voltages; mean of peak voltages is 36.2955 mV, standard deviation 17.8493 mV.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4596081&req=5

Figure 5: hn candidates and intrinsic properties. The hn candidates all have isolated frequencies within the range of 0.5717 ± 0.01 Hz. The set of 143 individual neurons spans ionic conductance space in a V-formation. A, hn candidate duty cycles spanned the range of 4.27% to 52.7%. B, The peak voltages are the mean supra-threshold oscillation peak voltages and these ranged from 0.7132 to 69.5211 mV. C, The first two panels are two-dimensional plots of duty cycles containing the same data as A. A histogram for hn candidate duty cycles (right); mean duty cycle is 21.33%, standard deviation 11.24. D, One-dimensional plots for peak voltages as function of individual hn conductances (left) make the correlations in B more apparent. These are further summarized in the middle plot showing the relationships between the three conductances and the peak voltages of the hn candidates with regression lines. Right, Histogram for hn candidate peak voltages; mean of peak voltages is 36.2955 mV, standard deviation 17.8493 mV.
Mentions: We created a population of model neurons with vastly ranging conductances and similar frequencies to examine the effects of modulation of the intrinsic properties of these centralized neurons on circuit output. Therefore, we generated 143 hub neuron candidates with frequencies of 0.5717 ± 0.01 Hz. Figure 5 shows their properties.

Bottom Line: We determined the effects of varying ḡCa , ḡK , and ḡh on the frequency, amplitude, and duty cycle of a single neuron oscillator.For a different set of network parameters, circuit behavior varied with the maximal conductances of the hub neuron.This demonstrates that neuromodulation of a single target neuron may dramatically alter the performance of an entire network when the network is in one state, but have almost no effect when the circuit is in a different state.

View Article: PubMed Central - HTML - PubMed

Affiliation: Volen Center for Complex Systems and Biology Department, Brandeis University, Waltham, Massachusetts 02454.

ABSTRACT

When does neuromodulation of a single neuron influence the output of the entire network? We constructed a five-cell circuit in which a neuron is at the center of the circuit and the remaining neurons form two distinct oscillatory subnetworks. All neurons were modeled as modified Morris-Lecar models with a hyperpolarization-activated conductance (ḡh ) in addition to calcium (ḡCa ), potassium (ḡK ), and leak conductances. We determined the effects of varying ḡCa , ḡK , and ḡh on the frequency, amplitude, and duty cycle of a single neuron oscillator. The frequency of the single neuron was highest when the ḡK and ḡh conductances were high and ḡCa was moderate whereas, in the traditional Morris-Lecar model, the highest frequencies occur when both ḡK and ḡCa are high. We randomly sampled parameter space to find 143 hub oscillators with nearly identical frequencies but with disparate maximal conductance, duty cycles, and burst amplitudes, and then embedded each of these hub neurons into networks with different sets of synaptic parameters. For one set of network parameters, circuit behavior was virtually identical regardless of the underlying conductances of the hub neuron. For a different set of network parameters, circuit behavior varied with the maximal conductances of the hub neuron. This demonstrates that neuromodulation of a single target neuron may dramatically alter the performance of an entire network when the network is in one state, but have almost no effect when the circuit is in a different state.

No MeSH data available.


Related in: MedlinePlus