Neuronal Spiking Reveals Universal Ground State in the Brain
Publication Title: Neuronal spiking in the mammalian forebrain is dominated by a heterogeneous ground state
Summary
- Question
- This study investigated how neurons in the mammalian forebrain exhibit distinct modes of activity, focusing on a universal low-rate 'ground state' (GS) mode and faster, more regular 'activated states' (AS). The researchers sought to determine the prevalence and characteristics of these modes and their role in brain function.
- Why it Matters
- Understanding how neurons operate in different modes is essential for decoding brain function. The findings shed light on how neural circuits balance persistent activity and responsiveness, which has implications for understanding information processing, brain energy use, and disorders where this balance is disrupted, such as epilepsy or cognitive dysfunction.
- Methods
- The researchers analyzed neural activity in six regions of the rodent forebrain (including the hippocampus, thalamus, and visual cortex) during waking and sleep states. They used statistical modeling to classify interspike intervals (time between neuronal spikes) into GS and AS modes. They also developed computational models to replicate these activity patterns and identify their underlying mechanisms.
- Key Findings
- The study revealed that most neuronal spikes occur in the GS mode, characterized by irregular spiking at low, neuron-specific rates (typically below 1 spike per second). In contrast, AS modes were associated with faster, more regular spiking that varied by brain region and state, such as during sensory processing or cognitive engagement. Computational models suggested that GS spiking arises from a balance of excitatory and inhibitory inputs, while AS spiking is linked to network-level dynamics.
- Implications
- The dominance of GS spiking highlights its potential role in maintaining baseline brain activity and network stability. AS spiking, on the other hand, likely facilitates communication and information transfer within and between brain regions. These insights could inform therapeutic strategies targeting neural activity patterns in neurological disorders.
- Next Steps
- Future research should explore how GS and AS modes contribute to specific behaviors and cognitive functions. Investigating how these modes are regulated by neuromodulators and testing their roles in maintaining network stability or enabling plasticity will also be important.
- Funding Information
- This research was supported by the National Institutes of Health (awards MH122391, MH13921, and U19NS107616). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Full Citation
Levenstein D, Gornet J, Huszár R, Girardeau G, Grosmark A, Peyrache A, Senzai Y, Watson B, Mizuseki K, Rinzel J, Buzsáki G. Neuronal spiking in the mammalian forebrain is dominated by a heterogeneous ground state. Neuron 2026, 114: 1246-1256.e3. PMID: 41713414, PMCID: PMC13225456, DOI: 10.1016/j.neuron.2025.12.018.
This AI-assisted summary has been reviewed and approved by at least one of the study's authors to ensure it accurately reflects the research.
Authors
Daniel Levenstein, PhD
First AuthorAssistant Professor
György Buzsáki
Last Author
Other Authors
Research Themes
Concepts
- Mammalian forebrain;
- Spike patterns;
- Low-rate;
- Neuronal firing patterns;
- Neuronal spiking;
- Neuronal dynamics;
- Excitatory neurons;
- Firing rate;
- Forebrain areas;
- Firing patterns;
- Irregular spiking;
- Response to stimuli;
- Forebrain;
- Neurons;
- Physiological importance;
- GS mode;
- Spikes;
- Network patterns;
- Modeling approach;
- Framework