Archives Italiennes De Biologie最新文献

In the present study we evaluated the long-term effects of lithium administration to a knock-out double transgenic mouse model (Smn-/-; SMN1A2G+/-; SMN2+/+) of Spinal Muscle Atrophy type III (SMA-III). This model is characterized by very low levels of the survival motor neuron protein, slow disease progression and motor neuron loss, which enables to detect disease-modifying effects at delayed time intervals. Lithium administration attenuates the decrease in motor activity and provides full protection from motor neuron loss occurring in SMA-III mice, throughout the disease course. In addition, lithium prevents motor neuron enlargement and motor neuron heterotopy and suppresses the occurrence of radial-like glial fibrillary acidic protein immunostaining in the ventral white matter of SMA-III mice. In SMA-III mice long-term lithium administration determines a dramatic increase of survival motor neuron protein levels in the spinal cord. These data demonstrate that long-term lithium administration during a long-lasting motor neuron disorder attenuates behavioural deficit and neuropathology. Since low level of survival motor neuron protein is bound to disease severity in SMA, the robust increase in protein level produced by lithium provides solid evidence which calls for further investigations considering lithium in the long-term treatment of spinal muscle atrophy.

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease resulting in increasing disability, being uniformly fatal. Since its approval in the 1990s, riluzole remained for long time the unique treatment, offering modest survival benefit. Most recently a second drug has been approved by the US Food and Drug Administration for treatment of ALS: edaravone. Significant advances have been made in the symptomatic management of the disease but more effective drug therapy targeting disease progression is still dreadfully needed, the success appearing almost a miracle. Recent discoveries related to genetics indicate divergent mechanisms of disease encouraging precision medicine leading to molecularly tailored interventions. The search for effective therapy still faces important challenges in the areas of both basic science and animal research, adequate translation of results into human clinical trials, inherent bias in human studies, and issues related to delays in clinical diagnosis. It is interesting to point out that ALS research may speed up drug development not only for this disease, but also for other more prevalent neurodegenerative diseases: the reverse is also conceivable.

Amyotrophic Lateral Sclerosis (ALS) is a fast progressive neurodegenerative disease characterized by muscle denervation, weakening and atrophy, which eventually culminates into death, mainly due to respiratory failure. The traditional view of ALS as a disorder affecting selectively motor neurons throughout the central nervous system has been progressively dispelled by innumerous lines of evidence indicating that other cells but motor neurons may be affected as well. Remarkably, this disorder is not limited to the motor system but rather configures as a systemic disease yielding a plethora of clinical signs. Among this broad clinical spectrum, sensory neuropathy occurring parallel to motor dysfunction is a quite frequent feature within ALS patients, which has spurred the interest of many investigators during the years. In line with this, morphological studies have confirmed that sensory neurons and axons' degeneration may occur in both ALS- experimental models and -patients. Noteworthy, this may have a nonetheless negligible role in ALS -related motor decline, as highlighted by recent studies showing that, degeneration of type I/II proprioceptive fibers is a primary source of alpha-motor neurons' death. These latter in fact, differently from gamma motor neurons, are a direct monosynaptic target of proprioceptive fibers. The present findings contribute to define a novel scenario of sensorimotor ALS pathophysiology where the gamma loop's fine connectivity may play a key role. In support to this view, in the present manuscript we provide a reappraisal on the role of single gamma loop's components in ALS.

The present study is aimed at further exploring structural and functional correlates of fatigue in Relapsing- Remitting Multiple Sclerosis (RRMS) patients by using a combined approach by means of transcranial magnetic stimulation (TMS) and a Diffusion Tensor Imaging (DTI). The physiopathology of fatigue in MS is still poorly understood, although a variety of pathogenic mechanisms has been proposed. Our working hypothesis is that diffuse microstructural white matter damage may subtend the cortico-subcortical functional disconnection described in patients with MS and fatigue. We enrolled 30 RRMS patients (mean age 39±13; age range 24-63 years) with mild neurological impairment Expanded Disability Status Scale <3.5, divided into two groups on the basis of their fatigue severity scale (FSS) scoring (cutoff ≥ 4). All the patients underwent a neurological evaluation, a brain MRI acquisition (including DTI study) and a neurophysiological assessment by means of TMS in a pre-movement facilitation paradigm. Our data showed a significant mean diffusivity (MD) increase (p=0.036) in left thalamo-frontal reconstructions in the MS patients with fatigue compared to those classified as non-fatigued. Moreover, significant correlations were observed between FSS scale and MD as well as planar coefficient (CP) values extracted from frontal-thalamic connections bilaterally. Instead, the pre-movement facilitation showed a significant difference between the groups with particular regard to the Reaction Time- MEP50ms amplitude (p=0.03). Our work confirms that fatigue is associated with a disruption of brain networks involved in motor preparation processes, depending on several frontal-thalamic pathways. Such findings can have an important role when dealing with fatigue management in MS patients and could be eventually used as prognostic marker of MS course.

The present manuscript investigates in two animal species by using two different experimental models of middle cerebral artery occlusion (permanent and transient), the neuroprotective effects of the dopamine receptor agonist apomorphine. These effects were evaluated by measuring the infarct volume and by counting muscle strength at different time points following the ischemic insult. Apomorphine at the dose of 3 mg/Kg when adminsitered at two hours following the occlusion of the middle cerebral artery was able to reduce significantly the infarct volume in the cortex of mice and the ischemic volume of the basal ganglia perfused by the perforant branches of the middle cerebral artery in the rat. In this latter case the behavioral evaluation (i.e. muscle strength) was preserved most effectively in the contralateral side at 24 and 72 hours. The present findings contribute to foster the concept that DA agonists might be useful in the treatment of cerebral ischemia. At the same time the behavioral improvement induced by DA administration following basal ganglia ischemia may be interpreted as the effects of an authentic disease modifying effect rather than a simple symtomatic relief due to a potential loss of DA containing axons in the basal ganglia. These data add on previous evidence showing analogous effects induced by the DA precursor L-DOPA. Apart from providing an evidence of a neuroprotective effect induced by increased DA stimulation the present data call for further studies aimed at comparing the effects of apomorphine with other DA agonists. In fact the quinoline moiety of apomorphine was claimed to protect neurons from a variety of insults independently from a DA agonist activity. The induction of protein clearing pathways appears to be potentially relevant for these effects.

Mother rats spend most of their time nursing their litter during the early stages of the postpartum period, only occasionally leaving the nest. The suckling stimulus from the pups elicits the adoption of nursing postures, during which milk ejection occurs, an event associated with the occurrence of non-REM (NREM) sleep in the rat. Despite this evidence, the characteristics of sleep during different nursing postures along the postpartum period remain unknown. The present study aims to describe the sleep pattern of mother rats while nursing, hovering over their pups and when being away from the pups. For this purpose, lactating females were implanted with electrodes for chronic polysomnographic recording. Simultaneous recordings of sleep-wakefulness cycle and maternal behaviors were performed in both the light and dark phases of the first and second postpartum weeks. Results indicate that while mothers were most of the time awake when hovering over pups and when staying away from pups, they mainly remained in NREM sleep when adopting low kyphosis posture, the most common nursing posture. The sleep-wake pattern during most maternal behaviors was quite stable between the light and dark phases of the first and second postpartum weeks. In addition, the sleep fragmentation was higher during the nursing bouts compared to that observed when mother rats slept without the pups, but sleep depth did not differ between these behaviors. Our results provide an original description of how mother rats synchronize their own sleep-wakefulness cycle with the maternal care of the pups during the postpartum period.

The effect of oxidative stress on muscle damage inducted by physical exercise is widely debated. It is generally agreed that endurance and intense exercise can increase oxidative stress and generate changes in antioxidant power inducing muscle damage; however, regular and moderate exercise can be beneficial for the health improving the antioxidant defense mechanisms in the majority of cases. Growing evidences suggest that an increased oxidative/nitrosative stress is involved in the pathogenesis of several muscular dystrophies (MDs). Notably, physical training has been considered useful for patients with these disorders. This review will focus on the involvement of oxidative stress in MDs and on the possible effects of physical activities to decrease oxidative damage and improve motor functions in MDs patients.

Several studies have shown that physical activity has positive effects on cognition in healthy older adults without cognitive complains but lesser is known about the effectiveness of aerobic exercise in patients suffering from Mild Cognitive Impairment (MCI). The aim of the present study was to systematically review the evidence from randomized controlled trials (RCTs) about the effects of aerobic exercise upon cognition in MCI patients. To this end, PubMed, Cochrane and Web of Science databases were analytically searched for RCTs including aerobic exercise interventions for MCI patients. There is evidence that aerobic exercise improves cognition in MCI patients. Overall research reported moderate effects for global cognition, logical memory, inhibitory control and divided attention. Due to methodological limitations of the investigated studies, findings should be interpreted with caution. Standardized training protocols, larger scale interventions and follow-ups may also provide better insight into the preventive effects of aerobic exercise on cognitive deterioration in MCI and its conversion into dementia.