Temperature elevations can induce switches to homoclinic action potentials that alter neural encoding and...

Area of Science:

• Computational neuroscience
• Mathematical biology
• Neurophysiology

Background:

• Action potential generation mechanisms are well-known, but their computational consequences require further exploration.
• Saddle-node homoclinic orbit bifurcation dynamics in action potentials have received limited research attention.
• Understanding these dynamics is crucial for comprehending brain electrical activity.

Purpose of the Study:

• To investigate action potential dynamics arising from saddle-node homoclinic orbit bifurcations.
• To explore the influence of physiological parameter changes on these dynamics.
• To determine the role of homoclinic spiking in neural network synchronization and brain activity states.

Main Methods:

• Utilized mathematical modeling to analyze action potential dynamics.
• Investigated the effects of physiological parameter variations, such as temperature elevation.
• Examined network synchronization patterns under conditions inducing homoclinic spiking.
• Correlated findings with in-vitro experimental data from rodent brains.

Main Results:

• Identified specific physiological parameter changes, like increased temperature, that promote homoclinic spiking.
• Demonstrated that homoclinic dynamics favor synchronization patterns in neural networks.
• Observed that synchronization becomes prominent when parameters induce homoclinic spiking.
• Found in-vitro evidence supporting the occurrence of homoclinic spikes in the rodent brain.

Conclusions:

• Homoclinic spikes, previously underestimated, may be prevalent in the brain.
• These spikes represent a critical link between biophysical parameter changes and abrupt shifts in brain activity states (asynchronous to synchronous).
• The findings provide a new perspective on how physiological changes impact neural network function and information processing.