Repetitive Neuronal Stimulation Reprograms Mature Neurons Into Immature States

Decades after electroconvulsive therapy (ECT) and repetitive transcranial magnetic stimulation (rTMS) became clinical workhorses for depression and schizophrenia, the cellular logic behind their durable benefits has remained elusive. Now, researchers have developed REPOPS, a patterned neuronal stimulation paradigm in mice intended to reproduce key features of ECT-like activation while allowing mechanistic interrogation.

In behavioral experiments, REPOPS boosted locomotor activity and reduced depression-like behaviors. Importantly, the treatment did not merely produce short-term excitation; it triggered lasting state changes reminiscent of ECT-like outcomes. These functional effects were accompanied by a striking cellular transformation: adult neurons entered a dematuration program, adopting gene expression signatures similar to early postnatal development.

Timing proved critical. Stimulation for three days yielded only transient transcriptional changes, whereas ten-day stimulation produced a stable dematuration state that persisted for more than a month. Genome-wide chromatin accessibility mapping further supported permanence, revealing widespread, durable remodeling of regulatory landscapes that can outlast the stimulation window.

The most surprising clue came from cell-cycle-linked molecular readouts. Although neurons are post-mitotic, REPOPS induced expression patterns characteristic of the G2/M phase in dividing cells, along with mitosis-associated nuclear hallmarks. These included histone phosphorylation, nuclear lamina disruption, and chromatin condensation—signatures consistent with nuclear reprogramming rather than transient activation.

To test causality, the team used genome editing to remove Cyclin B, a central G2/M transition regulator. Without Cyclin B, both nuclear reprogramming and stimulation-driven behavioral changes were reduced, implicating a mechanistic driver that connects “cell-cycle-like” signaling to the redefined neuronal identity.

The study then addressed how reprogramming altered computation. Using calcium imaging in behaving animals, the researchers observed a non-binary effect: REPOPS shifted information encoding in a patterned way. Spatial coding was suppressed, while speed-related coding was enhanced, and this altered coding strategy lasted for over two weeks.

Together, molecular, nuclear, epigenomic, and systems-level results support a model in which ECT-like stimulation creates an “intermediate state” of heightened plasticity. In this framework, neurons reside neither in a fully mature nor fully immature attractor state. Instead, the precise configuration may depend on stimulation strength, frequency, and context—factors that could be beneficial in depression but harmful under conditions such as epilepsy or neurodegeneration.

Finally, clinical relevance was suggested by reanalyzing postmortem RNA-seq datasets from mood-disorder patients. Dentate gyrus neurons from ECT-treated individuals showed an immature-like expression pattern similar to that observed in stimulated animals, strengthening the case that dematuration-like processes may occur in humans.