Synaptosomes isolated from cryopreserved MND motor cortex reveal altered calcium handling and reduced complex IV–linked respiration

Motor neuron disease (MND) is marked by progressive neurodegeneration in which presynaptic Ca2+-handling and mitochondrial metabolism are thought to be vulnerable, but direct functional studies in human brain are scarce because most material is frozen long-term. Here, we show that synaptosomes isolated from paired fresh and experimentally frozen mouse cortex, and from cryopreserved human motor cortex, retain recognisable synaptosome ultrastructural features, synaptic proteome enrichment, and dep