Neuronal ensembles in cortical function and disease - PubMed
5 days ago
- #optogenetics
- #neuronal ensembles
- #cortical function
- Neuronal ensembles are groups of coactive neurons and serve as physiological modules in the cerebral cortex.
- Calcium imaging and optogenetics enable mapping and manipulation of ensembles with single-cell resolution in the mouse visual cortex.
- Ensembles dominate cortical activity, can be generated endogenously or by sensory stimulation, and are imprinted by synchronous neuron activation.
- Intrinsic excitability mediates ensemble coactivation and reactivation, while UP states protect ongoing ensembles from external inputs.
- Neurons can belong to multiple ensembles, forming a combinatorial system for accurate and stable visual stimulus encoding.
- Ensembles include pyramidal neurons, interneurons, and inhibited 'offsemble' cells, with cross-inhibition ensuring orthogonality between ensembles.
- Astrocytic activation increases ensemble occurrence, and ensembles can persist for weeks, supporting long-term information storage.
- Ensembles capture recent stimulus history, implementing short-term memory, and are necessary and sufficient for visual discrimination and perceptual states.
- Altered ensembles are observed in epilepsy, schizophrenia, Alzheimer's disease, autism spectrum disorders, and medically-induced loss of consciousness.
- A proposed ensemble model describes them as functional units activating via trigger cells and silencing non-desired ensembles through cross-inhibition, forming a powerful memory and processing system.