Spatial working memory can be assessed in mice through the spontaneous alternation T-maze test. The T-maze is a T-shaped apparatus featuring a stem (start arm) and two lateral goal arms (left and ...right arms). The procedure is based on the natural tendency of rodents to prefer exploring a novel arm over a familiar one, which induces them to alternate the choice of the goal arm across repeated trials. During the task, in order to successfully alternate choices across trials, an animal has to remember which arm had been visited in the previous trial, which makes spontaneous alternation T-maze an optimal test for spatial working memory. As this test relies on a spontaneous behaviour and does not require rewards, punishments or pre-training, it represents a particularly useful tool for cognitive evaluation, both time-saving and animal-friendly. We describe here in detail the apparatus and the protocol, providing representative results on wild-type healthy mice.
Due to the COVID-19 pandemic, most memory clinics have had to suspend their activities. On the other hand, international dementia experts have recommended to provide urgently worldwide support for ...people living with dementia. This situation urges to play out new strategies to guarantee adequate care. Telemedicine and digital technology (DT) devices, such as smartphones, can be very helpful in remote monitoring and care. Technological devices such as videoconference or smartphone apps might be used for follow-up visits and support to patients and caregivers and to acquire digital markers of clinical progression. Hopefully, this dramatic situation would facilitate the process of progressive familiarization of neurologists with telemedicine and DT approach.
Imaging and histopathological studies have demonstrated that structural changes of the retina affect subjects with Alzheimer's disease (AD) or mild cognitive impairment (MCI). The aim of this study ...was to quantitatively investigate the retinal vessels in these disorders, using dynamic vessel analyzer (DVA) and optical coherence tomography angiography (OCTA) analysis. Twelve subjects with AD, 12 subjects with MCI, and 32 gender- and age-matched controls were prospectively enrolled. Mean ± SD age was 72.9 ± 7.2 years in the AD group, 76.3 ± 6.9 years in the MCI group, and 71.6 ± 5.9 years in the control group (p = 0.104). In the DVA dynamic analysis, the arterial dilation was decreased in the AD group (0.77 ± 2.06%), in the comparison with the control group (3.53 ± 1.25%, p = 0.002). The reaction amplitude was decreased both in AD (0.21 ± 1.80%, <0.0001) and MCI (2.29 ± 1.81%, p = 0.048) subjects, compared with controls (3.86 ± 1.94%). OCTA variables did not differ among groups. In the Pearson correlation analysis, amyloid β level in the cerebrospinal fluid was directly correlated with the arterial dilation (R = 0.441, p = 0.040) and reaction amplitude (R = 0.580, p = 0.005). This study demonstrate that Alzheimer's and MCI subjects are characterized by a significant impairment of the retinal neurovascular coupling. This impairment is inversely correlated with the level of amyloid β in the cerebrospinal fluid.
Background:
Neuroretinal atrophy is associated with whole-brain atrophy and disease activity in multiple sclerosis (MS). Recent findings support that subclinical visual pathway involvement might also ...occur in neuromyelitis optica spectrum disorders (NMOSDs).
Objective:
The objective of this study is to assess retinal thinning in MS and NMOSD and its association with disease activity.
Methods:
In total, 27 NMOSD and 54 propensity-score-matched MS patients underwent optical coherence tomography, visual acuity, and visual-evoked potentials at 2.4 years apart, in addition to routine clinical and magnetic resonance imaging (MRI) assessment. We excluded eyes with acute optic neuritis.
Results:
In NMOSD, we detected peripapillary retinal nerve fiber layer (pRNFL) thinning in patients with disease activity during follow-up (−0.494 µm/year), but not in stable patients (−0.012 µm/year). Macular ganglion cell-inner plexiform layer (GCIPL) thinning occurred instead in all patients (−0.279 µm/year). Relapsing–remitting multiple sclerosis (RRMS) meeting NEDA-3 criteria had no pRNFL or GCIPL thinning during follow-up. Active-disease RRMS and progressive MS, both active and stable, displayed pRNFL (−0.724, −0.586, −0.556 µm/year, respectively) and GCIPL loss.
Conclusion:
In MS, neuroretinal atrophy was associated with disease activity but occurred in progressive MS even when achieving NEDA-3 criteria. In NMOSD, pRNFL thinning was associated with non-ocular relapses due to a spreading of inflammatory activity. GCIPL thinning was found in all patients, supporting a primary retinal pathology targeting AQP4-rich structures.
Although the number of disease-modifying treatments for people with multiple sclerosis (pwMS) has meaningfully increased in the past years, targeting repair or compensation for central nervous system ...damage associated with the disease process remains an important clinical goal. With this aim, neurorehabilitation is a powerful approach targeting central nervous system plasticity. Another driver of brain plasticity is non-invasive brain stimulation (NIBS), receiving recent attention in neurology, particularly for its potential synergy with neurorehabilitation and as add-on treatment for several neurological conditions, from pain to fatigue to sensorimotor and cognitive deficits. In this review, we will resume the evidence exploring the neurobiological basis of NIBS and its applications to MS-related conditions.
Dravet syndrome (DS) is a severe epileptic encephalopathy caused mainly by heterozygous loss-of-function mutations of the SCN1A gene, indicating haploinsufficiency as the pathogenic mechanism. Here ...we tested whether catalytically dead Cas9 (dCas9)-mediated Scn1a gene activation can rescue Scn1a haploinsufficiency in a mouse DS model and restore physiological levels of its gene product, the Nav1.1 voltage-gated sodium channel. We screened single guide RNAs (sgRNAs) for their ability to stimulate Scn1a transcription in association with the dCas9 activation system. We identified a specific sgRNA that increases Scn1a gene expression levels in cell lines and primary neurons with high specificity. Nav1.1 protein levels were augmented, as was the ability of wild-type immature GABAergic interneurons to fire action potentials. A similar enhancement of Scn1a transcription was achieved in mature DS interneurons, rescuing their ability to fire. To test the therapeutic potential of this approach, we delivered the Scn1a-dCas9 activation system to DS pups using adeno-associated viruses. Parvalbumin interneurons recovered their firing ability, and febrile seizures were significantly attenuated. Our results pave the way for exploiting dCas9-based gene activation as an effective and targeted approach to DS and other disorders resulting from altered gene dosage.
Colasante et al. exploit an activatory CRISPR-targeting Scn1a gene promoter as a therapeutic strategy to rescue Scn1a haploinsufficiency in a mouse model of Dravet syndrome and restore physiological levels of its gene product, the Nav1.1 voltage-gated sodium channel.
Abstract
P23H is the most common mutation in the RHODOPSIN (RHO) gene leading to a dominant form of retinitis pigmentosa (RP), a rod photoreceptor degeneration that invariably causes vision loss. ...Specific disruption of the disease P23H RHO mutant while preserving the wild-type (WT) functional allele would be an invaluable therapy for this disease. However, various technologies tested in the past failed to achieve effective changes and consequently therapeutic benefits. We validated a CRISPR/Cas9 strategy to specifically inactivate the P23H RHO mutant, while preserving the WT allele in vitro. We, then, translated this approach in vivo by delivering the CRISPR/Cas9 components in murine Rho+/P23H mutant retinae. Targeted retinae presented a high rate of cleavage in the P23H but not WT Rho allele. This gene manipulation was sufficient to slow photoreceptor degeneration and improve retinal functions. To improve the translational potential of our approach, we tested intravitreal delivery of this system by means of adeno-associated viruses (AAVs). To this purpose, the employment of the AAV9-PHP.B resulted the most effective in disrupting the P23H Rho mutant. Finally, this approach was translated successfully in human cells engineered with the homozygous P23H RHO gene mutation. Overall, this is a significant proof-of-concept that gene allele specific targeting by CRISPR/Cas9 technology is specific and efficient and represents an unprecedented tool for treating RP and more broadly dominant genetic human disorders affecting the eye, as well as other tissues.
Introduction
The pandemic has implemented the need for new digital technologies as useful tools during the emergency and the long recovery phase that will follow. SARS-CoV-2 has strongly impacted ...stroke care with significant contraction in a number of patients treated.
Methods
This mini-review is an initiative of the “Digital Technologies, Web and Social Media Study Group” of the Italian Society of Neurology and briefly discusses digital tools for managing the acute phase and the rehabilitation after stroke, even considering the new apps that will improve the process of remote monitoring of patients after discharge at home.
Results
Telemedicine and digital technologies could play a role in each of the three stroke-belt stages: hyperacute treatment and reperfusion, acute care, etiological classification and secondary prevention and rehabilitation.
Conclusion
The global emergency represented by the COVID-19 pandemic can be the stimulus to accelerate the digitalization process in the field of stroke for the use of new methods on a large scale.
Understanding the mechanisms underlying progression and developing new treatments for progressive multiple sclerosis (PMS) are among the major challenges in the field of central nervous system (CNS) ...demyelinating diseases. Over the last 10 years, also because of some technological advances, the visual pathways have emerged as a useful platform to study the processes of demyelination/remyelination and their relationship with axonal degeneration/protection. The wider availability and technological advances in optical coherence tomography (OCT) have allowed to add information on structural neuroretinal changes, in addition to functional information provided by visual evoked potentials (VEPs). The present review will address the role of the visual pathway as a platform to assess functional and structural damage in MS, focusing in particular on the role of VEPs and OCT, alone or in combination, in the prognosis and monitoring of PMS.
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