Effect of acute stress on the expression of BDNF in the hippocampus of the Roman rats, a genetic model of stress-induced depression-like behaviour

The outbred Roman High- (RHA) and Roman Low-Avoidance (RLA) rats were psychogenetically selected for rapid vs. poor acquisition of active avoidance, respectively, and differ in many behavioural traits. Thus, RHA rats are impulsive, novelty seekers, and proactive copers, whereas RLA rats display behavioural traits that resemble some of the cardinal symptoms of depression (1). Beyond the monoamine hypothesis, compelling evidence suggests that mood disorders are characterized by reduced neuronal plasticity. Thus, it has been shown that exposure to stress and antidepressant treatments modulate the expression of neurotrophic factors, and that these changes show an anatomical specificity (2). To characterize the molecular and neuronal systems involved in the pathogenesis of stress-induced depression and in the mechanism of action of antidepressant treatments, we performed western blot (WB) and immunohistochemistry studies to assess the localization of the brain-derived neurotrophic factor (BDNF) in the hippocampus of RHA and RLA rats, both under basal conditions and after exposure to an acute stressor, i.e., the Forced Swim Test (FST). WB analyses showed that, under basal conditions, the relative levels of BDNF were lower in RLA vs. RHA rats, whereas, after FST, the relative levels of BDNF were markedly higher in the hippocampus of RLA vs. RHA rats. In brain tissue sections, BDNF-like immunoreactive material labeled neuronal cell bodies, proximal processes and varicose nerve fibers. Densitometric analysis used to compare immunostained brain sections from the two rat lines showed that, under basal conditions and upon FST, major differences were limited to the hippocampus proper, mostly to the CA3 and CA2 sectors, whereas the dentate gyrus (DG) showed no line-related differences. These results are at variance with previous studies showing that the expression of BDNF in the hippocampus is reduced in depressed patients and in rats exposed to stressors. In conclusion, the present study provides morphological evidence for an unexpected differential regional expression of BDNF in the hippocampus of RLA vs. RHA rats and supports the view that acute stress stimulates neuronal plasticity in genetic animal models of depression. This work was supported by grants from L.R. 07/2007, RAS project 2012

Anatomia Clavis et Clavus Medicinae

This illustrated book consists of seven chapters. The first 3, ranging from proto-history to the present day, address most of historical moments of the evolution of knowledge and teaching in Human Anatomy and related Sciences produced in South Sardinia, the City of Cagliari, its University and Anatomical Institutions. Chapter 4 is entirely devoted to the city of Cagliari Anatomical Theatres and Anatomical Rooms, places previously little known or totally unknown: an itinerary from Palazzo Belgrano seat of the Rectorate, to the Anatomical Institute of via Porcell. The latter, opened in 1922-23 has been Cagliari most important Anatomical Institution until 1998. Chapter 5 outlines the historical evolution of methods used for anatomical studies, from dissection to microscopy, tracing the links of Anatomy with various philosophical and scientific disciplines as well. Chapter 6 summarizes the general chronology and offers a prosopographical insight into the life, thought, and historical-social context of the Persons who have alternated in Anatomy teaching. Besides Professors, Sectors and Assistants, several of whom renowned protagonists of the international scientific world, are carefully considered. Chapter 7. Finally, we dedicate an ample space to the most recent changes that highlight the evolution of the investigation methods applied by optical microscopy and transmission and scanning electron microscopy; they encompass immunochemistry, morphometry, cell cultures, in a constantly transforming academic context. Developments in the last 55 years allowed us to write pages of history closer to our times and rich in memories of places, facts and people. They concern the Institute which later became a Department, the PhD program, the museum spaces in which excels the Anatomical Wax Museum, for its worldwide relevance and undisputed beauty of the works. Last, but not least, a space is dedicated to the Research Laboratories of the present-day Cytomorphology Section of the Department of Biomedical Sciences, and their contribution to the progress of scientific research in the morphological and functional field

Brain-derived neurotrophic factor (BDNF) and polysialylated-neural cell adhesion molecule (PSA-NCAM) in the human brainstem precerebellar nuclei from prenatal to adult age.

Occurrence and distribution of the neurotrophin brain-derived neurotrophic factor (BDNF) and polysialylated-neural cell adhesion molecule (PSA-NCAM), a neuroplasticity marker known to modulate BDNF signalling, were examined by immunohistochemistry in the human brainstem precerebellar nuclei at prenatal, perinatal and adult age. Western blot analysis performed in human brainstem showed for both molecules a single protein band compatible with the molecular weight of the dimeric form of mature BDNF and with that of PSA-NCAM. Detectability of both molecules up to 72 h post-mortem was also assessed in rat brain. In neuronal perikarya, BDNF-like immunoreactivity (LI) appeared as intracytoplasmic granules, whereas PSA-NCAM-LI appeared mostly as peripheral staining, indicative of membrane labelling; immunoreactivity to both substances also labelled nerve fibres and terminals. BDNF- and PSA-NCAM-LI occurred in the external cuneate nucleus, perihypoglossal nuclei, inferior olive complex, arcuate nucleus, lateral reticular formation, vestibular nuclei, pontine reticulotegmental and paramedian reticular nuclei, and pontine basilar nuclei. With few exceptions, for both substances the distribution pattern detected at prenatal age persisted later on, though the immunoreactivity appeared often higher in preand full-term newborns than in adult specimens. The results obtained suggest that BDNF operates in the development, maturation, maintenance and plasticity of human brainstem precerebellar neuronal systems. They also imply a multiple origin for the BDNF-LI of the human cerebellum. The codistribution of BDNF- and PSA-NCAM-LI in analyzed regions suggests that PSA-NCAM may modulate the functional interaction between BDNF and its high and low affinity receptors, an issue worth further analysis, particularly in view of the possible clinical significance of neuronal trophism in cerebellar neurodegenerative disorders.

Morphological changes induced by neuropeptide in vitro stimulation of the rat parotid gland

The effect of in vitro stimulation of rat parotid gland with the neuropeptides substance P, calcitonin gene-related peptide and galanin has been studied by microfilament fluorescence staining and in semithin sections, and compared to control incubations and in vitro stimulation with b­adrenergic and muscarinic agonists. Clear-cut aspects of massive granule exocytosis and cytoplasm vacuolation, indicative of protein and fluid secretion respectively, were obvious only after substance P stimulation, whereas treatment with galanin and calcitonin gene-related peptide produced little to no morphological changes. The results being in agreement with the outcome of other methodological approaches, these procedures appear reliable, may be effectively applied to the study of the functional regulation of secretory mechanisms, and may be particularly useful in human tissue analyses

Anti-Inflammatory Effect of Beta-Caryophyllene Mediated by the Involvement of TRPV1, BDNF and trkB in the Rat Cerebral Cortex after Hypoperfusion/Reperfusion

We have previously shown that bilateral common carotid artery occlusion followed by reperfusion (BCCAO/R) is a model to study early hypoperfusion/reperfusion-induced changes in biomarkers of the tissue physiological response to oxidative stress and inflammation. Thus in this study, we investigate with immunochemical assays if a single dose of beta-caryophyllene (BCP), administered before the BCCAO/R, can modulate the TRPV1, BDNF, and trkB receptor in the brain cortex; the glial markers GFAP and Iba1 were also examined. Frontal and temporal-occipital cortical regions were analyzed in two groups of male rats, sham-operated and submitted to BCCAO/R. Six hours before surgery, one group was gavage fed a dose of BCP (40 mg/per rat in 300 mu L of sunflower oil), the other was pre-treated with the vehicle alone. Western blot analysis showed that, in the frontal cortex of vehicle-treated rats, the BCCAO/R caused a TRPV1 decrease, an increment of trkB and GFAP, no change in BDNF and Iba1. The BCP treatment caused a decrease of BDNF and an increase of trkB levels in both sham and BCCAO/R conditions while inducing opposite changes in the case of TRPV1, whose levels became higher in BCCAO/R and lower in sham conditions. Present results highlight the role of BCP in modulating early events of the cerebral inflammation triggered by the BCCAO/R through the regulation of TRPV1 and the BDNF-trkB system

The human nucleus cuneatus contains discrete territories that share neurochemical features with the relay nuclei for nociceptive information

Traditionally, the spinal dorsal column and the gracile (GN) and cuneate (CN) nuclei are believed to be involved in somatic tactile and proprioceptive perceptions. However, more recent clinical and experimental studies show that this system is also involved in the neurotransmission of visceral nociceptive stimuli (Willis et al., Proc. Natl. Acad. Sci. USA 96, 7675, 1999; Pale?ek J., Physiol. Res. 53, S125, 2004). Early studies in our laboratory (Del Fiacco et al., Brain Res. 264, 142, 1983; Neuroscience, 12, 591, 1984) showed that, at variance with that of laboratory animals, the human CN contains discrete subregions that are strongly immunoreactive to substance P, a neuropeptide classically involved in pain transmission. Here we provide further information on the chemical neuroanatomy of the human dorsal column nuclei and show that the substance P-immunoreactive subregions of the CN retain the neurochemical features of the protopathic relay nuclei. Tissue distribution of a number of neuropeptides, trophic factors and neuroplasticity-associated proteins was analyzed by immunohistochemistry in postmortem specimens of medulla oblongata from subjects aged 21 gestation weeks to 78 years, with no signs of neuropathology. Immunoreactivity to neuropeptides calcitonin gene-related peptide, leucine- and methionine-enkephalin, somatostatin, galanin, and peptide histidine-isoleucine, to trophins of the Neurotrophin and glial-derived neurotrophic factor families and related receptors, and to the neuroplasticity-associated proteins growth-associated protein-43 and polysialylated-neural cell adhesion molecule labels neuronal elements in restricted areas of the cuneate nucleus, located along its dorsal edge or embedded in the white matter of the cuneate fasciculus. Multiple immunolabelling shows that, with respect to one another, the examined substances are distributed in these regions as in the superficial layers of the spinal dorsal horn and trigeminal subnucleus caudalis. By contrast, the immunoreactivity in the GN is usually sparse and not gathered in definite subregions. The results show that, at variance with that of laboratory mammals, including primates, the human CN contains clear-cut subregions with neurochemical features reminiscent of those present in the relay nuclei for protopathic and pain perception. Moreover, the peculiar localization of the examined substances suggests that the superficial layers of those regions may constitute a “gelatinous subnucleus”. The origin as well as the functional involvement of such innervation remains to be elucidated

Effects of forced swimming stress on ERK and histone H3 phosphorylation in limbic areas of Roman high-and low-avoidance rats

Stressful events evoke molecular adaptations of neural circuits through chromatin remodeling and regulation of gene expression. However, the identity of the molecular pathways activated by stress in experimental models of depression is not fully understood. We investigated the effect of acute forced swimming (FS) on the phosphorylation of the extracellular signal-regulated kinase (ERK)1/2 (pERK) and histone H3 (pH3) in limbic brain areas of genetic models of vulnerability (RLA, Roman low-avoidance rats) and resistance (RHA, Roman high-avoidance rats) to stress-induced depression-like behavior. We demonstrate that FS markedly increased the density of pERK-positive neurons in the infralimbic (ILCx) and the prelimbic area (PrLCx) of the prefrontal cortex (PFCx), the nucleus accumbens, and the dorsal blade of the hippocampal dentate gyrus to the same extent in RLA and RHA rats. In addition, FS induced a significant increase in the intensity of pERK immunoreactivity (IR) in neurons of the PFCx in both rat lines. However, RHA rats showed stronger pERK-IR than RLA rats in the ILCx both under basal and stressed conditions. Moreover, the density of pH3-positive neurons was equally increased by FS in the PFCx of both rat lines. Interestingly, pH3-IR was higher in RHA than RLA rats in PrLCx and ILCx, either under basal conditions or upon FS. Finally, colocalization analysis showed that in the PFCx of both rat lines, almost all pERK-positive cells express pH3, whereas only 50% of the pH3-positive neurons is also pERK-positive. Moreover, FS increased the percentage of neurons that express exclusively pH3, but reduced the percentage of cells expressing exclusively pERK. These results suggest that (i) the distinctive patterns of FS-induced ERK and H3 phosphorylation in the PFCx of RHA and RLA rats may represent molecular signatures of the behavioural traits that distinguish the two lines and (ii) FS-induced H3 phosphorylation is, at least in part, ERK-independent

Zika virus NS2A inhibits interferon signaling by degradation of STAT1 and STAT2

The Interferon (IFN) response is crucial to restrain pathogenic infections. Investigations into flavivirus-host interactions reported that the high virulence is linked to innate immune evasion. Zika Virus (ZIKV) has developed diversified strategies to evade the innate immune system. We report that the viral protein NS2A counteracts the IFN response by strongly suppressing the IFN signaling. NS2A targets transcription factors STAT1 and STAT2, to impede their nuclear localization, thereby suppressing the transcription of ISRE promoter and IFN-stimulated genes. We found that NS2A promotes degradation of STAT1 and STAT2. Treatment of NS2A transfected cells with MG132 restores the levels of both transcription factors, suggesting the involvement of the proteasome system. Given the impact that the IFN antagonism has on flavivirus virulence, the knowledge gained by characterizing the mechanism through which ZIKV evades the IFN response paves the ground for new strategies to attenuate the pathogenesis and to develop countermeasures against effective pharmacological targets

Effect of acute administration of Pistacia lentiscus L. essential oil on rat cerebral cortex following transient bilateral common carotid artery occlusion

<p>Abstract</p> <p>Background</p> <p>Ischemia/reperfusion leads to inflammation and oxidative stress which damages membrane highly polyunsaturated fatty acids (HPUFAs) and eventually induces neuronal death. This study evaluates the effect of the administration of <it>Pistacia lentiscus </it>L. essential oil (E.O.), a mixture of terpenes and sesquiterpenes, on modifications of fatty acid profile and endocannabinoid (eCB) congener concentrations induced by transient bilateral common carotid artery occlusion (BCCAO) in the rat frontal cortex and plasma.</p> <p>Methods</p> <p>Adult Wistar rats underwent BCCAO for 20 min followed by 30 min reperfusion (BCCAO/R). 6 hours before surgery, rats, randomly assigned to four groups, were gavaged either with E.O. (200 mg/0.45 ml of sunflower oil as vehicle) or with the vehicle alone.</p> <p>Results</p> <p>BCCAO/R triggered in frontal cortex a decrease of docosahexaenoic acid (DHA), the membrane highly polyunsaturated fatty acid most susceptible to oxidation. Pre-treatment with E.O. prevented this change and led further to decreased levels of the enzyme cyclooxygenase-2 (COX-2), as assessed by Western Blot. In plasma, only after BCCAO/R, E.O. administration increased both the ratio of DHA-to-its precursor, eicosapentaenoic acid (EPA), and levels of palmytoylethanolamide (PEA) and oleoylethanolamide (OEA).</p> <p>Conclusions</p> <p>Acute treatment with E.O. before BCCAO/R elicits changes both in the frontal cortex, where the BCCAO/R-induced decrease of DHA is apparently prevented and COX-2 expression decreases, and in plasma, where PEA and OEA levels and DHA biosynthesis increase. It is suggested that the increase of PEA and OEA plasma levels may induce DHA biosynthesis via peroxisome proliferator-activated receptor (PPAR) alpha activation, protecting brain tissue from ischemia/reperfusion injury.</p