Limits...
Gating multiple signals through detailed balance of excitation and inhibition in spiking networks.

Vogels TP, Abbott LF - Nat. Neurosci. (2009)

Bottom Line: We illustrate gating through detailed balance in large networks of integrate-and-fire neurons.We show successful gating of multiple signals and study failure modes that produce effects reminiscent of clinically observed pathologies.Provided that the individual signals are detectable, detailed balance has a large capacity for gating multiple signals.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurobiology and Behavior, Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, New York, USA.

ABSTRACT
Recent theoretical work has provided a basic understanding of signal propagation in networks of spiking neurons, but mechanisms for gating and controlling these signals have not been investigated previously. Here we introduce an idea for the gating of multiple signals in cortical networks that combines principles of signal propagation with aspects of balanced networks. Specifically, we studied networks in which incoming excitatory signals are normally cancelled by locally evoked inhibition, leaving the targeted layer unresponsive. Transmission can be gated 'on' by modulating excitatory and inhibitory gains to upset this detailed balance. We illustrate gating through detailed balance in large networks of integrate-and-fire neurons. We show successful gating of multiple signals and study failure modes that produce effects reminiscent of clinically observed pathologies. Provided that the individual signals are detectable, detailed balance has a large capacity for gating multiple signals.

Show MeSH

Related in: MedlinePlus

Network Pathologies(a) Average firing rate of the sender neurons without and with an oscillatory input. (b–d). Responses of excitatory (red histogram) and inhibitory (blue trace) receiver neurons with: b) Correct tuning. c) Weakened local inhibition, leading to a gating deficit. d) A hyperactive receiver region causing a response to the gating modulation. Conditions shown in the different columns are: No signal and no modulation. No signal but gated on. Signal on and gated on. Signal on but gated off. Firing rates are calculated in 5 ms bins.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2693069&req=5

Figure 5: Network Pathologies(a) Average firing rate of the sender neurons without and with an oscillatory input. (b–d). Responses of excitatory (red histogram) and inhibitory (blue trace) receiver neurons with: b) Correct tuning. c) Weakened local inhibition, leading to a gating deficit. d) A hyperactive receiver region causing a response to the gating modulation. Conditions shown in the different columns are: No signal and no modulation. No signal but gated on. Signal on and gated on. Signal on but gated off. Firing rates are calculated in 5 ms bins.

Mentions: The basic requirement to achieve a state of detailed balance is local inhibition strong enough to cancel signals in the gated-off state. In addition, the gain modulation used to unbalance and gate-on a pathway must not have an excessively destabilizing effect on the global excitatory-inhibitory balance of the network. With this in mind, we examined additional ways in which network gating can fail when tuning is relaxed. Fig. 5 shows gated off and gated on states with no signal and in the presence of an oscillatory signal. With proper tuning (Fig. 5b), the excitatory neurons of the receiver subnetwork respond robustly only when the signal is present and gating is on, although there is a weak transient response when the signal is present but gating is off.


Gating multiple signals through detailed balance of excitation and inhibition in spiking networks.

Vogels TP, Abbott LF - Nat. Neurosci. (2009)

Network Pathologies(a) Average firing rate of the sender neurons without and with an oscillatory input. (b–d). Responses of excitatory (red histogram) and inhibitory (blue trace) receiver neurons with: b) Correct tuning. c) Weakened local inhibition, leading to a gating deficit. d) A hyperactive receiver region causing a response to the gating modulation. Conditions shown in the different columns are: No signal and no modulation. No signal but gated on. Signal on and gated on. Signal on but gated off. Firing rates are calculated in 5 ms bins.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2693069&req=5

Figure 5: Network Pathologies(a) Average firing rate of the sender neurons without and with an oscillatory input. (b–d). Responses of excitatory (red histogram) and inhibitory (blue trace) receiver neurons with: b) Correct tuning. c) Weakened local inhibition, leading to a gating deficit. d) A hyperactive receiver region causing a response to the gating modulation. Conditions shown in the different columns are: No signal and no modulation. No signal but gated on. Signal on and gated on. Signal on but gated off. Firing rates are calculated in 5 ms bins.
Mentions: The basic requirement to achieve a state of detailed balance is local inhibition strong enough to cancel signals in the gated-off state. In addition, the gain modulation used to unbalance and gate-on a pathway must not have an excessively destabilizing effect on the global excitatory-inhibitory balance of the network. With this in mind, we examined additional ways in which network gating can fail when tuning is relaxed. Fig. 5 shows gated off and gated on states with no signal and in the presence of an oscillatory signal. With proper tuning (Fig. 5b), the excitatory neurons of the receiver subnetwork respond robustly only when the signal is present and gating is on, although there is a weak transient response when the signal is present but gating is off.

Bottom Line: We illustrate gating through detailed balance in large networks of integrate-and-fire neurons.We show successful gating of multiple signals and study failure modes that produce effects reminiscent of clinically observed pathologies.Provided that the individual signals are detectable, detailed balance has a large capacity for gating multiple signals.

View Article: PubMed Central - PubMed

Affiliation: Center for Neurobiology and Behavior, Department of Physiology and Cellular Biophysics, Columbia University College of Physicians and Surgeons, New York, New York, USA.

ABSTRACT
Recent theoretical work has provided a basic understanding of signal propagation in networks of spiking neurons, but mechanisms for gating and controlling these signals have not been investigated previously. Here we introduce an idea for the gating of multiple signals in cortical networks that combines principles of signal propagation with aspects of balanced networks. Specifically, we studied networks in which incoming excitatory signals are normally cancelled by locally evoked inhibition, leaving the targeted layer unresponsive. Transmission can be gated 'on' by modulating excitatory and inhibitory gains to upset this detailed balance. We illustrate gating through detailed balance in large networks of integrate-and-fire neurons. We show successful gating of multiple signals and study failure modes that produce effects reminiscent of clinically observed pathologies. Provided that the individual signals are detectable, detailed balance has a large capacity for gating multiple signals.

Show MeSH
Related in: MedlinePlus