Olfaction, among the First Senses to Develop and Decline

Olfaction is one of the most conserved senses across species. It plays a crucial role in animals’ and humans’ life by influencing food intake, reproduction and social behavior. The olfactory system is composed of a peripheral neuroepithelium and a central olfactory nerve and is one of the few central nervous system (CNS) structures with direct access to the external environment without passage through the Blood Brain Barrier (BBB). This makes this nerve system of importance for understanding how exogenous stimuli may contribute to neuronal damage as well as for diagnostic and therapeutic purposes. Interestingly, olfactory activity physiologically declines with aging, but its alteration can be further impaired by various neurological conditions. For example, in progressive neurodegenerative disorders, such as Alzheimer’s disease (AD), olfaction is the first sense to be impaired before the onset of cognitive symptoms, suggesting that olfactory transmission may characterize early neural network imbalances. In this work, we will explore the main olfactory anatomical structures, the cytoarchitecture, the neurogenesis, several pathological conditions characterized by olfactory deficit and the potential use of this sense to diagnose and treat CNS pathologies

Effects of Persea americana leaf extracts on body weight and liver lipids in rats fed hyperlipidaemic diet

The effects of aqueous and methanolic leaf extracts of Persea americana on body weight and liver lipids in rats were studied. Male albino rats were fed a modified diet containing 0.5% cholesterol and0.25% cholic acid to provoke hyperlipidaemia. The hyperlipidaemic rats were given 10 mg/kg body weight of either aqueous or methanolic extract of P. americana leaf daily for 8 weeks. There were nosignificant differences (p>0.05) in the overall body weight gain of the hyperlipidaemic rats compared to normal control. However, the administration of the aqueous and methanolic extracts provoked 14 and25% reduction, respectively, in the body weight gain of the treated rats compared to the hyperlipidaemic control. Mean liver weights were markedly increased (

Notch1 hallmarks fibrillary depositions in sporadic Alzheimer’s disease

Background: Notch1 signaling is a cellular cascade with a fundamental role from brain development to adult brain function. Reduction in Notch1 affects synaptic plasticity, memory and olfaction. On the other hand, Notch1 overactivation after brain injury is detrimental for neuronal survival. Some familial Alzheimer’s disease (FAD) mutations in Presenilins can affect Notch1 processing/activation. Others report that Notch1 is overexpressed in sporadic Alzheimer’s disease (AD). These works indicate that imbalances in Notch1 may be implicated in AD pathophysiology. In this study, we addressed whether Notch1 alteration can be considered a hallmark of AD.Results: Immunohistochemical analysis of Notch1 on cortical and hippocampal tissue from post-mortem patients indicates an accumulation of Notch1 in plaque-like structures in the brain parenchyma of subjects with sporadic AD. Further analysis shows that displaced Notch1 is associated with fibrillary tangles/plaques. Biochemical validation confirms an accumulation of Notch1 in cytosolic brain fractions. This increase in protein is not accompanied with a raise in the Notch1 targets Hes1 and Hey1. Examination of the cerebrospinal fluid (CSF) indicates that the full length and truncations of the Notch1 protein are reduced in AD patients hinting at an accumulation in the brain parenchyma.Conclusions: Our research indicates that Notch1 is significantly displaced and accumulated in fibrillary structures in the susceptible hippocampal and cortical regions of sporadic AD patients. The dominant deposition of Notch1 in the brain parenchyma and its general signal reduction in neurons is consistent in all the AD patients analyzed and suggests that Notch1 may potentially be considered a novel hallmark of AD

Notch1 Regulates Hippocampal Plasticity Through Interaction with the Reelin Pathway, Glutamatergic Transmission and CREB Signaling

Notch signaling plays a crucial role in adult brain function such as synaptic plasticity, memory and olfaction. Several reports suggest an involvement of this pathway in neurodegenerative dementia. Yet, to date, the mechanism underlying Notch activity in mature neurons remains unresolved. In this work, we investigate how Notch regulates synaptic potentiation and contributes to the establishment of memory in mice. We observe that Notch1 is a postsynaptic receptor with functional interactions with the Reelin receptor, apolipoprotein E receptor 2 (ApoER2) and the ionotropic receptor, N-methyl-D-aspartate receptor (NMDAR). Targeted loss of Notch1 in the hippocampal CA fields affects Reelin signaling by influencing Dab1 expression and impairs the synaptic potentiation achieved through Reelin stimulation. Further analysis indicates that loss of Notch1 affects the expression and composition of the NMDAR but not AMPAR. Glutamatergic signaling is further compromised through downregulation of CamKII and its secondary and tertiary messengers resulting in reduced cAMP response element-binding (CREB) signaling. Our results identify Notch1 as an important regulator of mechanisms involved in synaptic plasticity and memory formation. These findings emphasize the possible involvement of this signaling receptor in dementia. HIGHLIGHTS: In this paper, we propose a mechanism for Notch1-dependent plasticity that likely underlies the function of Notch1 in memory formation: Notch1 interacts with another important developmental pathway, the Reelin cascade.Notch1 regulates both NMDAR expression and composition.Notch1 influences a cascade of cellular events culminating in CREB activation

Misura della posizione del pilota tramite una action camera

In questa tesi viene messo a punto un sistema per determinare la posizione del pilota durante la guida di una motocicletta. Questo metodo utilizza una telecamera montata sulla moto che riprende il pilota. Tramite le immagini aquisite dalla telecamera si stima la posizione del pilota rispetto alla moto. Dopo aver messo a punto il metodo tramiteuna procedura di calibrazione, verranno effettuate delle prove sperimentali con una motocicletta strumentataope

WAVELET ANALYSIS OF HUMAN PHOTORECEPTORAL RESPONSE

Feature detection of biomedical signals is crucial for deepening our knowledge of the physiological phenomena giving rise to them. To achieve this aim, even if many analytic approaches have been suggested only few are able to deal with signals whose features are time dependent, and to provide useful clinical information. In this work we use the wavelet analysis to extract peculiarities of the early response of the photoreceptoral human system, known as a-wave ERG-component. The analysis of the a-wave features is important since this component reflects the functional integrity of the two populations of photoreceptors, rods and cones whose activation dynamics are not well known. Moreover, in incipient photoreceptoral pathologies the eventual anomalies in a-wave are not always detectable with a naked eye analysis of the traces. We here propose the possibility to discriminate the pathologic from the healthy traces throughout the differentiation of their time-frequency characteristics, revealed by the wavelet analysis. The investigated pathologies are the Achromatopsia, a cone disease and the Congenital Stationary Night Blindness, a rod trouble. The results show that the number of stable frequencies present and their times of occurrence are indicative of the status of the retinal photoreceptors. In particular, in the pathological cases, the frequency components shift toward lower values and change their times of occurrence, with respect to healthy traces