Protocol for quantifying muscle fiber size, number, and central nucleation of mouse skeletal muscle cross-sections using Myotally software.

Here, we present a protocol for using Myotally, a user-friendly software for fast, automated quantification of muscle fiber size, number, and central nucleation from immunofluorescent stains of mouse skeletal muscle cross-sections. We describe steps for installing the software, preparing compatible images, finding the file path, and selecting key parameters like image quality and size limits. We also detail optional features, such as measuring mean fluorescence.

Spatial transcriptomic clocks reveal cell proximity effects in brain ageing.

Old age is associated with a decline in cognitive function and an increase in neurodegenerative disease risk. Brain ageing is complex and is accompanied by many cellular changes. Furthermore, the influence that aged cells have on neighbouring cells and how this contributes to tissue decline is unknown.

A mouse model of volumetric muscle loss and therapeutic scaffold implantation.

Skeletal myofibers naturally regenerate after damage; however, impaired muscle function can result in cases when a prominent portion of skeletal muscle mass is lost, for example, following traumatic muscle injury. Volumetric muscle loss can be modeled in mice using a surgical model of muscle ablation to study the pathology of volumetric muscle loss and to test experimental treatments, such as the implantation of acellular scaffolds, which promote de novo myogenesis and angiogenesis. Here we provide step-by-step instructions to perform full-thickness surgical ablation, using biopsy punches, and to remove a large volume of the tibialis anterior muscle of the lower limb in mice.

Spatiotemporal transcriptomic profiling and modeling of mouse brain at single-cell resolution reveals cell proximity effects of aging and rejuvenation.

Old age is associated with a decline in cognitive function and an increase in neurodegenerative disease risk. Brain aging is complex and accompanied by many cellular changes. However, the influence that aged cells have on neighboring cells and how this contributes to tissue decline is unknown.