381 research outputs found
The cerebellum, the hypothalamus and behavior
The cerebellum has been classically considered as the subcortical center for motor control. How- ever, accumulating experimental evidence has revealed that it also plays an important role in cognition, for instance, in learning and memory, as well as in emotional behavior and nonsomatic activities, such as visceral and immunological responses
Parvalbumin, calbindin, or calretinin in cortically projecting and GABAergic, cholinergic, or glutamatergic basal forebrain neurons of the rat
The basal forebrain (BF) plays an important role in modulating cortical activity and facilitating processes of attention, learning, and memory. This role is subserved by cholinergic neurons but also requires the participation of other noncholinergic neurons. Noncholinergic neurons include gamma-amino butyric acidergic (GABAergic) neurons, some of which project in parallel with the cholinergic cells to the cerebral cortex, others of which project caudally or locally. With the original aim of distinguishing different subgroups of GABAergic neurons, we examined immunostaining for the calcium binding proteins (CBPs) parvalbumin (Parv), calbindin (Calb), and calretinin (Calret) in the rat. Although the CBP(+) cell groups were distributed in a coextensive manner with the GABAergic cells, they were collectively more numerous. Of cells retrogradely labeled with cholera toxin (CT) from the prefrontal or parietal cortex, Parv(+) and Calb(+) cells, but not Calret(+) cells, represented substantial proportions ( approximately 35-45% each) that collectively were greater than that of GABAergic projection neurons. From dual immunostaining for the CBPs and glutamic acid decarboxylase (GAD), it appeared that the vast majority (>90%) of the Parv(+) group was GAD(+), whereas only a small minority (40%) and Calret(+) (>80%) neurons were immunopositive for phosphate-activated glutaminase, the synthetic enzyme for transmitter glutamate. The results suggested that, whereas Calret(+) cells predominantly comprise caudally or locally projecting, possibly glutamatergic BF neurons, Parv(+) cells likely comprise the cortically projecting GABAergic BF neurons and Calb(+) cells the cortically projecting, possibly glutamatergic BF neurons that would collectively participate with the cholinergic cells in the modulation of cortical activity. Copyright 2003 Wiley-Liss, Inc
Behaviour and Degenerative Changes in the Basal Forebrain Systems of Aged Rats (12 Months Old) after Levo-Acetyl-Carnitine Treatments
One group of six male control rats [12 months old] and one group of six male rats of the same age, singularly maintained in a cage, and treated with acetyl-L-carnitine-HCl [(gamma-trimethyl-beta-acetyl-butyrobetaine-HCl: Sigma-Tau code ST200 or ALCAR: 60 mg/kg/day[7]/po)] for six months were tested in the spatial learning/memory Morris mazewater task and for atrophy and cell loss in seven myelo- and cytostructurally defined basal forebrain (BF) cholinergic regions [Freddi et al., 2009]. Coronal sections 25 ?m thick were cut through the BF regions and processed every 200 ?m for choline acetyltransferase (ChAT) immunohistochemistry. The ALCAR-treated rats had significantly shorter exit times on the Morris maze-water task test than the control rats (average \ub1 SD 28.3 \ub1 12.4 s vs. 61.16 \ub1 4.67 s; t = 6.07, DOF = 10, P = 0.0001). Degenerative morphological changes in the BF ChAT-positive cells were observed in the substantia innominata pars anterior of the control rats but not in the treated animals (P < 0.05). In the BF, the counted and estimated average number of ChAT + cells in the 12-month-old ALCAR-treated rats (ChAT-ALCAR-12+ [Nos. 2,3,4]) was higher but not significantly (15.288 \ub1 3281) than that counted and estimated in the 12-month-old control rats [(ChAT-CT-12 [Nos. 1,2,3]) (11.508 \ub1 3868), t = 1.82, DOF = 10, P = 0.319]. In the substantia innominata pars posterior, the ChAT+ cells were significantly more numerous (P < 0.05) in the 12-month-old ALCAR-treated rats (ChAT-ALCAR-12 + [Nos. 2,3,4]) than in the control rats (ChAT-CT-12 [Nos. 1,2,3]). Above all, these results dem-onstrate that treatment with ALCAR from the age of 6 up to 12 months significantly attenuated spatial learning/memory impairment on the Morris maze-water behavioral task (P < 0.001) and also importantly reduced degeneration in size and number of cholinergic cells in the nucleus basalis magnocellularis of the BF. Accordingly, the surviving cholinergic neurons found in the BF of the ALCAR-treated rats might play an important role in modulating cortical activity and facilitating processes of attention, learning and memory
Electroencephalographic Changes after a Marathon at 4300 M of Altitude
Running at altitude is gaining greater popularity but it may expose participants to the risk of acute mountain sickness (AMS). The study investigated electroencephalographic (EEG) changes and eventual symptoms suggestive of AMS in 5 well-trained lowland native male runners (average age, 38.2 \uf0b1 4.6 years; VO2 peak 61.4 \uf0b1 2.7 mL\ub7kg\u20131\ub7min\u20131 at sea level; best marathon performance at sea level under 3 hours), who completed a marathon at 4300 m altitude. EEG, per-centage of peripheral arterial oxygen saturation (% SpaO2) and heart rate (HR) were recorded during wakefulness at rest (supine position) and in comfort: 1) at sea level; 2) at 3600 m after 32 - 38 hours of acute acclimatization; 3) at 4300 m after 145 - 153 hours of chronic acclimatization; and 4) at 4300 m immediately after a marathon race. Symptoms of AMS were evaluated with the Lake Louise questionnaire before any ECG recording. There was a significant decrease in low-voltage high-frequency activities at rest after acute hypoxic-hypobaric exposure at 3600 m as compared to sea level. After six days of acclimatization at 4300 m there was a significant increase in the power of low-voltage high-frequency activities, particularly beta and gamma, indicating an aroused waking state and an integrated activity across widely dis-tributed cortical regions. An increase in the power of low-voltage high-frequency activities over the entire cortex was observed, particularly after completion of the marathon at 4300 m. The increase in the high-frequency activities was probably due to direct and indirect reflex activation of the forebrain and reticular activating system involved in behav-ioral and metabolic integration of autonomic control and arousal and due to residual activation of the somatomotor and parietal cortex after the end of the marathon. Lake Louise score always resulted lower than 3, indicating no signs of AMS in all the runners. The results of this study indicate that in well-trained and acclimatized athletes, arousal has a protective role in preventing excessive oxygen deprivation also after an endurance exercise performed at high altitude. The absence of AMS fond in our study bear out that well trained and acclimatized runners, can safely participate in a marathon at high altitude that gives rise to temporary EEG changes without inducing paroxysmal phenomena
Blood Chemistry, Acid- Base, Electrolyte, Blood Lactate Metabolism and Sleep at 3480 m in Mountain Marathon Runners
Altered blood chemistry, acid-base and electrolyte are suggested determinants of sleep disturbance, with frequent arousal at high altitude even in well and long-trained altitude marathon runners. In this sample of experienced altitude marathon runners with maximal aerobic power at sea level of 61.4 \ub1 2.7 ml/kg 121\u387min 121 we found that pO2 and percent of oxygen saturation (%SO2) were lower at 2050 m and 3480 m than at sea level; pO2 was higher after 38 - 41 hours than after 30 - 31 hours of acclimatization at 3480 m (P < 0.05). After ascent to 3480 m %SO2 decreased (P < 0.003). Compared to sea level values, pH increased at high altitude (P < 0.05) consistent with changes in pCO2 and [HCO3-] (P < 0.05). Nocturnal %SpaO2 at a sleeping altitude of 3480 m was lower (P < 0.05) than at sea level. At high altitude, the percent of wake (W) time and delay falling asleep (DFA) increased, whereas non-rapid eye movement sleep (N-REM), REM sleep and total sleep time (TST) decreased (P < 0.05). Simple regression analysis disclosed a significant correlation between the changes in TST and the percent of REM sleep and the changes in %SpaO2 recorded during sleep (P < 0.05). Simple regression analysis showed a positive correlation between the changes in pO2 at higher altitude and the percent of W and of TST (P < 0.05). The changes in pO2, tCO2 and [HCO3-] correlated negatively and significantly with the percent of REM sleep changes at high altitude (P < 0.05). The TST changes at high altitude correlated positively with the changes in pO2 and pH and correlated negatively with the changes in %SO2, pCO2, tCO2, and [HCO3-] (P < 0.05). The changes in the percent of W at high altitude correlated significantly and positively with the changes in bases excess [BE] at high altitude (P < 0.05). The changes in the percent of REM sleep correlated significantly and positively with the changes in [iCa++] and [BE] and negatively with the changes in buffered bases [BB] and [BEeffective] (P < 0.05). The change in the percent of NREM + REM sleep at high altitude correlated significantly and positively with the changes in [BE] and [BB] concentration (P < 0.05). The increase in DFA at high altitude correlated significantly and negatively with the changes in pCO2 and significantly and negatively with the changes in [K+] (P < 0.05). Simple regression analysis demonstrated that the changes in pH at high altitude correlated positively and significantly with the percent of W and the DFA and negatively with the percent of changes in NREM sleep, REM sleep, NREM + REM sleep (P < 0.05). The decrease in the TST at high altitude correlated significantly and negatively with the changes in pCO2, tCO2, [HCO3-]and [K+] (P < 0.05). Our data demonstrate that the arterialized ear lobe techniques we used for evaluating most of the changes in blood chemistry, acid-base, electrolyte and blood lactate metabolism are suitable for clinical and laboratory assessment and are important predictors of the quality and quantity of acclimatization and sleep at high altitude
Copanlisib synergizes with conventional and targeted agents including venetoclax in B- And T-cell lymphoma models
Copanlisib is a pan-class I phosphoinositide 3-kinase (PI3K) inhibitor with preferred activity toward PI3Ka and PI3Kd. Despite the clear overall clinical benefit, the number of patients achieving complete remissions with the single agent is relatively low, a problem shared by the vast majority of targeted agents. Here, we searched for novel copanlisib-based combinations. Copanlisib was tested as a single agent, in combination with an additional 17 drugs in 26 cell lines derived from mantle cell lymphoma (MCL), marginal zone lymphoma (MZL), and T-cell lymphomas. In vivo experiments, transcriptome analyses, and immunoblotting experiments were also performed. Copanlisib as a single agent showed in vitro dose-dependent antitumor activity in the vast majority of the models. Combination screening identified several compounds that synergized with copanlisib. The strongest combination was with the B-cell lymphoma 2 (BCL2) inhibitor venetoclax. The benefit of the combination over single agents was also validated in an MZL xenograft model and in MCL primary cells, and was due to increased induction of apoptosis, an effect likely sustained by the reduction of the antiapoptotic proteins myeloid cell leukemia 1 (MCL1) and BCL-XL, observed in MCL and MZL cell lines, respectively. These data supported the rationale for the design of the Swiss Group for Clinical Cancer Research (SAKK) 66/18phase 1 study currently exploring the combination of copanlisib and venetoclax in relapsed/refractory lymphomas
Adult cardiac stem cells are multipotent and robustly myogenic: c-kit expression is necessary but not sufficient for their identification
Multipotent adult resident cardiac stem cells (CSCs) were first identified by the expression of c-kit, the stem cell factor receptor. However, in the adult myocardium c-kit alone cannot distinguish CSCs from other c-kit-expressing (c-kitpos) cells. The adult heart indeed contains a heterogeneous mixture of c-kitpos cells, mainly composed of mast and endothelial/progenitor cells. This heterogeneity of cardiac c-kitpos cells has generated confusion and controversy about the existence and role of CSCs in the adult heart. Here, to unravel CSC identity within the heterogeneous c-kit-expressing cardiac cell population, c-kitpos cardiac cells were separated through CD45-positive or -negative sorting followed by c-kitpos sorting. The blood/endothelial lineage-committed (Lineagepos) CD45posc-kitpos cardiac cells were compared to CD45neg(Lineageneg/Linneg) c-kitpos cardiac cells for stemness and myogenic properties in vitro and in vivo. The majority (~90%) of the resident c-kitpos cardiac cells are blood/endothelial lineage-committed CD45posCD31posc-kitpos cells. In contrast, the LinnegCD45negc-kitpos cardiac cell cohort, which represents 10% of the total c-kitpos cells, contain all the cardiac cells with the properties of adult multipotent CSCs. These characteristics are absent from the c-kitneg and the blood/endothelial lineage-committed c-kitpos cardiac cells. Single Linnegc-kitpos cell-derived clones, which represent only 1–2% of total c-kitpos myocardial cells, when stimulated with TGF-β/Wnt molecules, acquire full transcriptome and protein expression, sarcomere organisation, spontaneous contraction and electrophysiological properties of differentiated cardiomyocytes (CMs). Genetically tagged cloned progeny of one Linnegc-kitpos cell when injected into the infarcted myocardium, results in significant regeneration of new CMs, arterioles and capillaries, derived from the injected cells. The CSC’s myogenic regenerative capacity is dependent on commitment to the CM lineage through activation of the SMAD2 pathway. Such regeneration was not apparent when blood/endothelial lineage-committed c-kitpos cardiac cells were injected. Thus, among the cardiac c-kitpos cell cohort only a very small fraction has the phenotype and the differentiation/regenerative potential characteristics of true multipotent CSCs
Caracterização do genoma e teste de proteção vacinal para amostras do vÃrus da bronquite infecciosa das aves associadas a surtos ?atÃpicos?? da doença.
Projeto/Plano de Ação: 02.05.01.018
Tripotential Differentiation of Adherently Expandable Neural Stem (NS) Cells
BACKGROUND: A recent study has shown that pure neural stem cells can be derived from embryonic stem (ES) cells and primary brain tissue. In the presence of fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF), this population can be continuously expanded in adherent conditions. In analogy to continuously self-renewing ES cells, these cells were termed ‘NS’ cells (Conti et al., PLoS Biol 3: e283, 2005). While NS cells have been shown to readily generate neurons and astrocytes, their differentiation into oligodendrocytes has remained enigmatic, raising concerns as to whether they truly represent tripotential neural stem cells. METHODOLOGY/PRINCIPAL FINDINGS: Here we provide evidence that NS cells are indeed tripotent. Upon proliferation with FGF2, platelet-derived growth factor (PDGF) and forskolin, followed by differentiation in the presence of thyroid hormone (T3) and ascorbic acid NS cells efficiently generate oligodendrocytes (∼20%) alongside astrocytes (∼40%) and neurons (∼10%). Mature oligodendroglial differentiation was confirmed by transplantation data showing that NS cell-derived oligodendrocytes ensheath host axons in the brain of myelin-deficient rats. CONCLUSIONS/SIGNIFICANCE: In addition to delineating NS cells as a potential donor source for myelin repair, our data strongly support the view that these adherently expandable cells represent bona fide tripotential neural stem cells
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