Figure 5.

Presynaptic alterations in NMJs of male mice fed with HFD. The sternomastoid muscle of mice fed with high fat and standard diets were fixed and stained with BTX-Alexa549 to label AChR and with antibodies against neurofilament (green) to label axons. A. Example of an NMJ from an age-matched non-obese mouse fed the standard diet. B. Example of an NMJ from an HFD-obese mouse (7 months). The AChE (red) channel shows the original area of the synapse. The absence of overlying AChR (blue) and NF (green) signals from areas identified by AChEs staining (dashed lines) indicates regions where both axon terminals and AChRs were lost. C. A high-resolution confocal image of a representative NMJ from 9-month-old HFD-obese mouse displaying partial denervation. The inset images show faint AChR clusters (see bracket) without an overlying nerve terminal. D. Example of an NMJ of an HFD-obese mice (9 months) showing regions of high receptor density covered by the nerve terminal (arrows) and regions of low density of AChR devoid of nerves (brackets). E. Quantification of results from a series of synapses labelled with fluorescent BTX and neurofilament antibody. F. Example of an NMJ of an HFD-obese mouse (9 months) contacted by two axons (arrows). Scale bars: 10 μm.