This study evaluated how the brain of male mice processes future memory and found that synchronized activity in the hippocampus CA1 neurons during sleep is linked with preset cells. Scientists investigated how neuronal ensembles are transformed into memory engrams.
Vital vectors containing TRE-hKikGR were developed for hippocampal injections, and stereotactic surgery was performed to implant the gradient refractive index (GRIN) lenses for imaging and Electroencephalogram (EEG)/ electromyogram (EMG) electrodes for sleep stage differentiation. This study was published in Nature Communications, double-transgenic mice can conduct engram labelling and calcium imaging using microscopy and EEG/EMG recordings after recovery.
Cosine similarity thresholds used to select engram cells, identified engram cells were tracked using KikGR expression and corrected and analyzed using Ca2+ imaging data for motion tracking. Specific subgroups and their co-occurrences with engram-to-be cells were analyzed using dynamic engram activity.
Non-negative matrix factorization (NMF), with adjustments for the Akaike Information Criterion (AIC), was used to extract the coactivity patterns. In non-engram populations, principal component analysis (PCA) and independent component analysis (ICA) were used to analyse the latent coactivity structures.
