27 research outputs found

    Running towards amblyopia recovery

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    Amblyopia is a neurodevelopmental disorder of the visual cortex arising from abnormal visual experience early in life which is a major cause of impaired vision in infants and young children (prevalence around 3.5%). Current treatments such as eye patching are ineffective in a large number of patients, especially when applied after the juvenile critical period. Physical exercise has been recently shown to enhance adult visual cortical plasticity and to promote visual acuity recovery. With the aim to understand the potentialities for translational applications, we investigated the effects of voluntary physical activity on recovery of depth perception in adult amblyopic rats with unrestricted binocular vision; visual acuity recovery was also assessed. We report that three weeks of voluntary physical activity (free running) induced a marked and long-lasting recovery of both depth perception and visual acuity. In the primary visual cortex, ocular dominance recovered both for excitatory and inhibitory cells and was linked to activation of a specific intracortical GABAergic circuit

    Experience-dependent reduction of soluble β-amyloid oligomers and rescue of cognitive abilities in middle-age Ts65Dn mice, a model of Down syndrome

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    Down syndrome (DS) is the most diffused genetic cause of intellectual disability and, after the age of forty, is invariantly associated with Alzheimer's disease (AD). In the last years, the prolongation of life expectancy in people with DS renders the need for intervention paradigms aimed at improving mental disability and counteracting AD pathology particularly urgent. At present, however, there are no effective therapeutic strategies for DS and concomitant AD in mid-life people. The most intensively studied mouse model of DS is the Ts65Dn line, which summarizes the main hallmarks of the DS phenotype, included severe learning and memory deficits and age-dependent AD-like pathology. Here we report for the first time that middle-age Ts65Dn mice display a marked increase in soluble Aβ oligomer levels in their hippocampus. Moreover, we found that long-term exposure to environmental enrichment (EE), a widely used paradigm that increases sensory-motor stimulation, reduces Aβ oligomers and rescues spatial memory abilities in trisomic mice. Our findings underscore the potential of EE procedures as a non-invasive paradigm for counteracting brain aging processes in DS subjects

    Intranasal delivery of BDNF rescues memory deficits in AD11 mice and reduces brain microgliosis

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    A decrease in brain-derived neurotrophic factor (BDNF), a neurotrophin essential for synaptic function, plasticity and neuronal survival, is evident early in the progression of Alzheimer’s disease (AD), being apparent in subjects with mild cognitive impairment or mild AD, and both proBDNF and mature BDNF levels are positively correlated with cognitive measures. BDNF delivery is, therefore, considered of great interest as a potentially useful therapeutic strategy to contrast AD. Invasive BDNF administration has indeed been recently used in animal models of AD with promising results in rescuing memory deficits, synaptic density and cell loss. Here, we tested whether non-invasive intranasal administration of different BDNF concentrations after the onset of cognitive and anatomical deficits (6 months of age) could rescue neuropathological and memory deficits in AD11 mice, a model of NGF deprivation-induced neurodegeneration. In addition to AD hallmarks, we investigated BDNF effects on microglia presence in the brain of AD11 mice, since alterations in microglia activation have been associated with ageing-related cognitive decline and with the progression of neurodegenerative diseases, including AD. We found that intranasal delivery of 42 pmol BDNF (1 μM), but not PBS, was sufficient to completely rescue performance of AD11 mice both in the object recognition test and in the object context test. No further improvement was obtained with 420 pmol (10 μM) BDNF dose. The strong improvement in memory performance in BDNF-treated mice was not accompanied by an amelioration of AD-like pathology, Aβ burden, tau hyperphosphorylation and cholinergic deficit, but there was a dramatic decrease of CD11b immunoreactive brain microglia. These results reinforce the potential therapeutic uses of BDNF in AD and the non-invasive intranasal route as an effective delivery strategy of BDNF to the brain. They also strengthen the connection between neuroinflammation and neurodegenerative dementia and suggest microglia as a possible mediator of BDNF therapeutic actions in the brain
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