Aged mice lacking a nerve growth receptor have weaker muscles
Strength-test scores were 41.75% in mice lacking the receptor versus 100% in controls, whose performance served as the reference.
Limit: Lifelong absence of p75 could not isolate its effects specifically in old age
Edited by Boris Djordjevic · AgingResearch.News
In C57BL/6J mice of both sexes aged 24–26 months, researchers tested how lifelong absence of p75, a receptor for nerve growth signals, affected nerve–muscle connections and strength. The animal experiment compared genetically altered mice with control littermates. Researchers assessed strength by testing how much weight mice could hold and for how long, accounting for body weight.
Although nerve–muscle connections retained their overall shape, a greater share had lost their nerve supply in mice lacking p75. The connections also had less coverage by terminal Schwann cells, which support nerve endings. Receptors on muscle cells that receive signals to contract were less stable. Mice lacking p75 also performed worse in the strength test. The authors interpreted the findings as consistent with cumulative effects of persistent p75 deficiency during aging.
Why it matters
Deterioration of nerve–muscle connections contributes to age-related weakness. The authors suggest p75 may be relevant to efforts to prevent age-associated decline in nerve–muscle function.
Caveats
Lifelong absence of p75 could not isolate its effects specifically in old age. The mouse experiment did not test whether changing p75 activity later in life could preserve muscle function.
The paper
p75 neurotrophin receptor preserves neuromuscular synapse stability and muscle strength during aging
University of Concepción; Austral University of Chile
npj Aging, May 16, 2026, Open access
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