Strategic Modification of Gut Microbiota through Oral Bacteriotherapy Influences Hypoxia Inducible Factor-1α: Therapeutic Implication in Alzheimer’s Disease

Dysbiosis contributes to Alzheimer’s disease (AD) pathogenesis, and oral bacteriotherapy represents a promising preventative and therapeutic opportunity to remodel gut microbiota and to delay AD onset and progression by reducing neuroinflammation and amyloid and tau proteins aggregation. Specifically, SLAB51 multi-strain probiotic formulation positively influences multiple neuro-chemical pathways, but exact links between probiotics oral consumption and cerebral beneficial effects remain a gap of knowledge. Considering that cerebral blood oxygenation is particularly reduced in AD and that the decreased neurovascular function contributes to AD damages, hypoxia conditioning represents an encouraging strategy to cure diseases of the central nervous system. In this work, 8-week-old 3xTg-AD and wild-type mice were chronically supplemented with SLAB51 to evaluate effects on hypoxia-inducible factor-1α (HIF-1α), a key molecule regulating host-microbial crosstalk and a potential target in neurodegenerative pathologies. We report evidence that chronic supplementation with SLAB51 enhanced cerebral expression of HIF-1α and decreased levels of prolyl hydroxylase 2 (PHD2), an oxygen dependent regulator of HIF-1α degradation; moreover, it successfully counteracted the increase of inducible nitric oxide synthase (iNOS) brain expression and nitric oxide plasma levels in AD mice. Altogether, the results demonstrate an additional mechanism through which SLAB51 exerts neuroprotective and anti-inflammatory effects in this model of AD.

Impact of Motivation on Selected Aspects of Attention in Children with ADHD

Earlier reports showed the co-occurrence of a motivation deficit in children with ADHD. The purpose of this study was to assess the impact of extrinsic motivation on selected aspects of attention in children with ADHD, as well as to measure cortical activity and dimensions of motivation as per the self-determination theory. The study included 30 children with ADHD and 30 typically developing (TD) children aged 9–13 years. Children with ADHD exhibited a higher theta/beta power ratio (TBR) in the midline and a lower regional cerebral blood oxygenation (rCBO2) level in prefrontal areas measured using the HEG ratio compared to TD children. Children with ADHD were more likely to undertake activity under the pressure of external stimuli and exhibited attention deficits regarding vigilance, visual search and divided attention. Differences between groups regarding attention decreased in conditions of increased motivation, indicating that motivation can reduce cognitive deficits in children with ADHD.

Characteristic of Mayer Waves in Electrophysiological, Hemodynamic and Vascular Signals

We evaluated the properties of oscillations in the Mayer waves (MW) frequency range ([Formula: see text][Formula: see text]Hz) detected in blood pressure, heart rate variability, cerebral blood oxygenation changes and evolution of electroencephalographic (EEG) rhythms to elucidate the mechanisms of MW generation. We examined the persistence of MW in different signals and stability of their oscillations on the level of individual MW waveforms, which was achieved by applying matching pursuit (MP). MP yields adaptive time-frequency approximation of signal’s structures in terms of frequency, amplitude, time occurrence, and time-span. The number of waveforms contributing to 95% of the energy of the signals was vastly different for the time series, but the average number of waveforms conforming to the MW criteria was almost the same ([Formula: see text] per 120[Formula: see text]s epoch). In all the investigated signals, MW had the same distributions of frequency and the number of cycles. We show that the MW energy ratios in different signals varied strongly, [Formula: see text]. The highest percentage of MW energy was observed in blood pressure signals, heart rate variability, and reduced hemoglobin, in contrast to brain signals and oxygenated hemoglobin. The percentage of MW energy was related to the strength of causal influence exerted by them on the other signals. Our results indicate existence of a common mechanism of MW generation and support the hypothesis of MW generation in the baroreflex loop; however, they do not exclude the action of a central pacemaker.