Alzheimer disease

Neuronal activity regulates the regional vulnerability to amyloid-β deposition Bero, A. W. et al. Nat. Neurosci. doi: 10.1038/nn.2801

Endogenous neuronal activity could account for region-specific amyloid-β (Aβ) deposition in the brain, according to a new study. Using mouse models of amyloid deposition, Bero et al. demonstrated that specific areas of the brain exhibited increased neuronal activity, which directly correlated with increased interstitial fluid Aβ concentrations and subsequent Aβ deposition. These findings may explain the vulnerability of specific brain regions to Aβ deposition in Alzheimer disease.

Parkinson disease

Reduced uptake of [18F]FDOPA PET in asymptomatic welders with occupational manganese exposure Criswell, S. R. et al. Neurology 76, 1296–1301 (2011)

While investigating welders who have been exposed to high levels of manganese, researchers have found that asymptomatic individuals show reduced function of the nigrostriatal dopamine system. This finding suggests that welders develop manganese-induced neurotoxic damage to nigrostriatal neurons, which could predispose them to parkinsonism in later life.

Pain

Loss-of-function mutations in sodium channel NaV1.7 cause anosmia Weiss, J. et al. Nature 472, 186–190 (2011)

The voltage-gated sodium channel NaV1.7 is known to be necessary for humans to experience pain, and patients with loss-of-function mutations in the gene encoding NaV1.7 (SCN9A) are also unable to sense odors, according to a new study published in Nature. The research group have now generated mouse models to investigate congenital general anosmia and the genetic basis of our sense of smell.

Neurodegenerative disease

Skin biopsy is useful for the antemortem diagnosis of neuronal intranuclear inclusion disease Sone, J. et al. Neurology 76, 1372–1376 (2011)

Histochemical and electron microscopic analysis of skin biopsies can aid the diagnosis of neuronal intranuclear inclusion disease (NIID), research published in Neurology has revealed. NIID presents with a variety of clinical manifestations, and antemortem diagnosis of the disease is difficult. In skin biopsy samples from patients with NIID, the investigators could identify intranuclear inclusions that were identical to those found in neuronal cells. These data indicate that skin biopsy represents an effective and minimally invasive method to diagnose NIID.