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Neonatal hypoxia-ischemia (HI) is the leading cause of mortality and morbidity in newborns, occurring in approximately 2% of live births. Neuroprotective actions of progesterone (PROG) have already been described in animal models of brain lesions. However, PROG actions on neonates are still controversial. Here, we treated male Wistar rats exposed to HI with PROG. Five experimental groups were defined (n = 6/group) according to the scheme of PROG administration (10 mg/kg): SHAM (animals submitted to a fictitious surgery, without ischemia induction, and maintained under normoxia), HI (animals undergoing HI), BEFORE (animals undergoing HI and receiving PROG immediately before HI), AFTER (animals undergoing HI and receiving PROG at 6 and 24 h after HI) and BEFORE/AFTER (animals undergoing HI and receiving PROG immediately before and 6 and 24 h after HI). At P14 (7 days following HI), the volumes of lesion of the cerebral hemisphere and the hippocampus ipsilateral to the cerebral ischemia were evaluated, along with p-Akt, cleaved caspase-3 and GFAP expression in the hippocampus. PROG reduces the loss of brain tissue caused by HI. Moreover, when administered after HI, PROG was able to increase p-Akt expression and reduce both cleaved caspase-3 and GFAP expression in the hippocampus. In summary, it was possible to observe a neuroprotective action of PROG on the brain of neonatal animals exposed to experimental HI. This is the first study suggesting PROG-dependent Akt activation is able to regulate negatively cleaved caspase-3 and GFAP expression protecting neonatal hypoxic-ischemic brain tissue from apoptosis and reactive gliosis.

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INTRODUCTION: Neonatal Hypoxia-Ischemia (HI) is a major cause of morbidity and mortality, and is frequently associated with short and long-term neurologic and cognitive impairments. The HI injury causes mitochondrial damage leading to increased production of reactive oxygen species (ROS). Phytoestrogens are non-steroidal plant substances structurally and functionally similar to estrogen. Coumestrol is a potent isoflavonoid with a protective effect against ischemic brain damage in adult rats. Our aim was to determine if coumestrol treatment following neonatal HI attenuates the long-term cognitive deficits induced by neonatal HI, as well as to investigate one possible mechanism underlying its potential effect. METHODS: On the 7th postnatal day, male Wistar rats were submitted to the Levine-Rice HI model. Intraperitoneal injections of 20 mg/kg of coumestrol, or vehicle, were administered immediately pre-hypoxia or 3 h post-hypoxia. At 12 h after HI the mitochondrial status and ROS levels were determined. At 60th postnatal day the cognitive deficits were revealed in the Morris water maze reference and working spatial memories. Following behavioral analysis, histological assessment was performed and reactive astrogliosis was measured by GFAP expression. RESULTS: Results demonstrate that both pre- and post-HI administration of coumestrol were able to counteract the long-term cognitive and morphological impairments caused by HI, as well as to block the late reactive astrogliosis. The pre-HI administration of coumestrol was able to prevent the early mitochondrial dysfunction in the hippocampus of injured rat pups. CONCLUSION: Present data suggest that coumestrol exerts protection against experimental neonatal brain hypoxia-ischemia through, at least in part, early modulation of mitochondrial function.

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The authors hereby declare that the Figure 4 in page eight of the paper "Stem cells from human exfoliated deciduous teeth modulate early astrocyte response after spinal cord contusion" authored by Fabrício Nicola and colleagues (DOI: 10.1007/s12035-018-1127-4) was mistakenly included.

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The transplantation of stem cells from human exfoliated deciduous teeth (SHED) has been studied as a possible treatment strategy for spinal cord injuries (SCIs) due to its potential for promoting tissue protection and functional recovery. The aim of the present study was to investigate the effects of the early transplantation of SHED on glial scar formation and astrocytic reaction after an experimental model of SCI. Wistar rats were spinalized using the NYU Impactor. Animals were randomly distributed into three groups: control (naive) (animal with no manipulation); SCI (receiving laminectomy followed by SCI and treated with vehicle), and SHED (SCI rat treated with intraspinal SHED transplantation, 1 h after SCI). In vitro investigation demonstrated that SHED were able to express mesenchymal stem cells, vimentin and S100B markers, related with neural progenitor and glial cells, respectively. The acute SHED transplantation promoted functional recovery, measured as from the first week after spinal cord contusion by Basso, Beattie, and Bresnahan scale. Twenty-four and 48 h after lesion, flow cytometry revealed a spinal cord vimentin+ cells increment in the SHED group. The increase of vimentin+ cells was confirmed by immunofluorescence. Moreover, the bioavailability of astrocytic proteins such as S100B and Kir4.1 shown to be increased in the spinal cord of SHED group, whereas there was a glial scar reduction, as indicated by ELISA and Western blot techniques. The presented results support that SHED act as a neuroprotector agent after transplantation, probably through paracrine signaling to reduce glial scar formation, inducing tissue plasticity and functional recovery.

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Emerging evidence has suggested global histone H4 acetylation status plays an important role in neural plasticity. For instance, the imbalance of this epigenetic marker has been hypothesized as a key factor for the development and progression of several neurological diseases. Likewise, astrocytic reactivity - a well-known process that markedly influences the tissue remodeling after a central nervous system injury - is crucial for tissue remodeling after spinal cord injury (SCI). However, the linkage between the above-mentioned mechanisms after SCI remains poorly understood. We sought to investigate the relation between both glial fibrillary acidic protein (GFAP) and S100 calcium-binding protein B (S100B) (astrocytic reactivity classical markers) and global histone H4 acetylation levels. Sixty-one male Wistar rats (aged ~3 months) were divided into the following groups: sham; 6 hours post-SCI; 24 hours post-SCI; 48 hours post-SCI; 72 hours post-SCI; and 7 days post-SCI. The results suggested that GFAP, but not S100B was associated with global histone H4 acetylation levels. Moreover, global histone H4 acetylation levels exhibited a complex pattern after SCI, encompassing at least three clearly defined phases (first phase: no changes in the 6, 24 and 48 hours post-SCI groups; second phase: increased levels in the 72 hours post-SCI group; and a third phase: return to levels similar to control in the 7 days post-SCI group). Overall, these findings suggest global H4 acetylation levels exhibit distinct patterns of expression during the first week post-SCI, which may be associated with GFAP levels in the perilesional tissue. Current data encourage studies using H4 acetylation as a possible biomarker for tissue remodeling after spinal cord injury.

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During development, the brain goes through fundamental processes, including organization of neural networks and plasticity. Environmental interventions may change initial brain programming, leading to long-lasting effects and altering the susceptibility to psychopathologies, including depression disorder. It is known that depression is a psychiatric disorder with a high prevalence worldwide, including high rates among adolescents. In this study, we evaluated whether social isolation in the prepubertal period and chronic use of high-fat diet (HFD) may induce depressive-like behavior in male adult rats. We also investigated hippocampal plasticity markers and neurotransmitter systems. We found both social isolation and HFD induced a depressive-like behavior in the forced swimming task. Moreover, chronic HFD reduced synaptic markers in hippocampus, demonstrated by reductions in ßIII-tubulin (neuronal marker), PSD-95, SNAP-25, and neurotrophin-3. The HFD group also presented decreased glutamatergic and GABAergic receptors subunits. On the other hand, stress affected hippocampal brain-derived neurotrophic factor (BDNF) signaling pathways, and increased expression of subunit of the NMDA receptor (NR2A). Both factors (stress and diet) decreased GR in the hippocampus without affecting plasma corticosterone at basal levels. Interactions between early stress and HFD access were observed only in the BNDF receptor (tropomyosin receptor kinase B; TrkB) and synaptophysin. In summary, these findings showed that a brief social isolation and chronic HFD, during a sensitive developmental period, cause depressive-like behavior in adulthood. The mechanisms underlying these behavioral effects may involve changes in the levels of synaptic proteins in hippocampus: HFD consumption appears to affect synaptic markers, while social isolation affected BDNF signaling more significantly.

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BackgroundHypoxia-ischemia (HI) is a major cause of neurological damage in preterm newborn. Swimming during pregnancy alters the offspring's brain development. We tested the effects of swimming during pregnancy in the very immature rat brain.MethodsFemale Wistar rats (n=12) were assigned to the sedentary (SE, n=6) or the swimming (SW, n=6) group. From gestational day 0 (GD0) to GD21 the rats in the SW group were made to swim for 20 min/day. HI on postnatal day (PND) 3 rats caused sensorimotor and cognitive impairments. Animals were distributed into SE sham (SESH), sedentary HIP3 (SEHI), swimming sham (SWSH), and swimming HIP3 (SWHI) groups. At PND4 and PND5, Na+/K+-ATPase activity and brain-derived neurotrophic factor (BDNF) levels were assessed. During lactation and adulthood, neurological reflexes, sensorimotor, anxiety-related, and cognitive evaluations were made, followed by histological assessment at PND60.ResultsAt early stages, swimming caused an increase in hippocampal BDNF levels and in the maintenance of Na+/K+-ATPase function in the SWHI group. The SWHI group showed smaller lesions and the preservation of white matter tracts. SEHI animals showed a delay in reflex maturation, which was reverted in the SWHI group. HIP3 induced spatial memory deficits and hypomyelination in SEHI rats, which was reverted in the SWHI group.ConclusionSwimming during pregnancy neuroprotected the brains against HI in very immature neonatal rats.

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Regular physical activity has shown to improve the quality of life and to prevent age-related memory deficits. Memory processing requires proper regulation of several enzymes such as sodium-potassium adenosine triphosphatase (Na+, K+-ATPase) and acetylcholinesterase (AChE), which have a pivotal role in neuronal transmission. The present study investigated the effects of a treadmill running protocol in young (3 months), mature (6 months) and aged (22 months) Wistar rats, on: (a) cognitive function, as assessed in the Water maze spatial tasks; (b) Na+, K+-ATPase and AChE activities in the hippocampus following cognitive training alone or treadmill running combined with cognitive training. Animals of all ages were assigned to naïve (with no behavioral or exercise training), sedentary (non-exercised, with cognitive training) and exercised (20 min of daily running sessions, 3 times per week for 4 weeks and with cognitive training) groups. Cognition was assessed by reference and working memory tasks run in the Morris Water maze; 24 h after last session of behavioral testing, hippocampi were collected for biochemical analysis. Results demonstrated that: (a) a moderate treadmill running exercise prevented spatial learning and memory deficits in aged rats; (b) training in the Water maze increased both Na+, K+-ATPase and AChE activities in the hippocampus of mature and aged rats; (c) aged exercised rats displayed an even further increase of Na+, K+-ATPase activity in the hippocampus, (d) enzyme activity correlated with memory performance in aged rats. It is suggested that exercise prevents spatial memory deficits in aged rats probably through the activation of Na+, K+-ATPase in the hippocampus.

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BACKGROUND: In cases where autologous bone graft reconstruction is not possible (such as comminuted fractures, bone graft reabsorption, or infection) and the use of synthetic material is required, polymethylmethacrylate (PMMA) use is a safe and efficient solution. Studies comparing the incidence of postoperative complications between autologous and synthetic cranioplasty are heterogeneous, not allowing a conclusion of which is the best material for skull defects reconstruction. Current medical literature lacks prospective well-delineated studies with long-term follow-up that analyze the impact of antibiotic use in PMMA cranial reconstruction of moderate and large defects. METHODS: A prospective series of patients, who underwent cranioplasty reconstruction with PMMA impregnated with antibiotic, were followed for 2 years. Authors collected data regarding demographic status, clinical conditions, surgical information, and its complications. RESULTS: A total of 58 patients completed full follow-up with a mean group age of 40 years and a male predominance (77%). Major complications that required surgical management were identified in 5 patients, and 10 patients evolved with minor complications. Postoperative surgical site infection incidence was 3.2%. CONCLUSION: The infection rate in patients submitted to PMMA flap cranioplasty impregnated with antibiotic is significantly inferior comparing to the data described in medical literature. A lower infection incidence impacts secondary endpoints such as minimizing surgical morbidity, mortality, hospitalization period, and, consequently, costs.