Selected Brain Areas Research Articles

Transcranial direct current stimulation influences the cardiac autonomic nervous control

To investigate whether the manipulation of brain excitability by transcranial direct current stimulation (tDCS) modulates the heart rate variability (HRV), the effect of tDCS applied at rest on the left temporal lobe in athletes (AG) and non-athletes (NAG) was evaluated. The HRV parameters (natural logarithms of LF, HF, and LF/HF) was assessed in 20 healthy men before, and immediately after tDCS and sham stimulation. After anodal tDCS in AG the parasympathetic activity (HFlog) increased (P<0.01) and the sympathetic activity (LFlog) and sympatho-vagal balance (LF/HFlog) decreased (P<0.01), whereas no significant effects were detected in NAG (P>0.05). No significant changes in HRV indexes were provoked by sham stimulation in both AG and NAG (P>0.05). In conclusion, tDCS applied on the left temporal lobe significantly increased the overall HRV in AG, enhancing the parasympathetic and decreasing the sympathetic modulation of heart rate. Consequently the sympatho-vagal balance decreased at rest in AG but not in NAG. Releasing a weak electric current to stimulate selected brain areas may induce favorable effects on the autonomic control to the heart in highly fit subjects.

Differential distribution of DHA-phospholipids in rat brain after feeding: A lipidomic approach

On a per-weight basis, the brain is the organ richest in lipids, including a remarkable proportion of polyunsaturated fatty acids (PUFAs) of the omega 3 series, namely eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. The cerebral effects of exogenous DHA likely depend on its degree of incorporation into neuronal phospholipids and on its distribution among the various brain structures, after intake. Hence, because PUFAs are not evenly distributed among the brain phospholipid classes and because the existence of class-specific phospholipases that regulate their turnover, we sought to investigate the incorporation of omega 3 PUFAs in selected brain areas regions and specific phospholipid classes. Rats ( n=7) were administered, by oral gavage, 100 mg/kg/d of a commercially available fish oil (containing ∼84% of long-chain omega 3 fatty acids, of which ∼38% of DHA and ∼46% of EPA). Control rats ( n=7) received liquid paraffin. This treatment was continued for 30 days. Thereafter, we dissected three areas, namely the hippocampus, the striatum, and the cortex. Quantization of individual phospholipid classes and their molecular species was performed by ESI-MS/MS. Principal component analysis was used to examine the variation of the molecular lipid profiles (as percentage) induced by omega 3 supplementation. Our results show that provision of omega 3 fatty acids to rats results in their incorporation into brain phospholipids, the extent of which is lower in the striatum as compared with cortex and hippocampus. These data might in part explain the mixed therapeutic results obtained in neurological disorders, many of which are likely region-specific.

GW1929: A nonthiazolidinedione PPARγ agonist, ameliorates neurological damage in global cerebral ischemic-reperfusion injury through reduction in inflammation and DNA fragmentation

Transient global cerebral ischemia results in acute neurodegeneration in selective brain areas. Global cerebral ischemic-reperfusion (IR) injury induced selective hippocampal damage results into various neurobehavioral deficits including spatial memory and learning deficiencies. In this study, we have investigated the protective effects of a nonthiazolidinedione PPARγ agonist, N-(2-benzoylphenyl)-O-[2-(methyl-2-pyridinylamino)ethyl]- l-tyrosine (GW1929), against global cerebral IR injury induced neurobehavioral deficits and brain damage in gerbils. Bilateral carotid artery occlusion induced global cerebral ischemia in gerbils resulted in neurological deficits, hyperlocomotion, reduced response latency in passive avoidance test and hippocampal damage. Hippocampal neurodegeneration after cerebral IR injury was also associated with significant increase in iNOS and MMP-9 immunoreactivity along with TNFα and IL-6 levels. Massive apoptotic DNA fragmentation as evident from increased TUNEL (terminal deoxynucleotidyl transferase mediated dUTP nick end labelling)-positive cells was also observed in the CA1 hippocampal region of IR challenged gerbils. GW1929 treatment significantly ameliorated cerebral IR induced neurological symptoms, hyperlocomotion, cognitive deficits and hippocampal neuronal damage in CA1 hippocampus region in gerbils. Significant reduction in IR injury induced iNOS and MMP-9 immunoreactivity, TNFα and IL-6 levels and apoptotic DNA fragmentation was also observed with GW1929 treatment. Pioglitazone, thiazolidinedione PPARγ agonist also exhibited similar effects on inflammatory parameters after global cerebral IR injury. In summary, this study demonstrates neuroprotective effects of GW1929 in global cerebral IR injury induced neurobehavioral deficits and brain pathology which may be attributed to reduced inflammation and apoptotic DNA fragmentation, suggesting therapeutic potential of PPARγ agonists in cerebral IR injury.

Time-dependent effects of escitalopram on brain derived neurotrophic factor (BDNF) and neuroplasticity related targets in the central nervous system of rats

Chronic treatment with antidepressants affects several proteins linked to neuroplasticity, particularly brain derived neurotrophic factor (BDNF): this leads eventually to their therapeutic effects. It is possible that also for putative early therapeutic onset, antidepressants may act by promoting cellular adaptations linked to neuroplasticity. Escitalopram, known to be already effective in preclinical models of depression after 7 days, allowed us to investigate whether two effective treatment regimens (7 and 21 days) may contribute to synaptic plasticity by acting on BDNF signalling. We focused our attention on two regulators of BDNF transcription, CREB and CaRF (calcium responsive factor), and on kinases, CaMKII, ERK1/2 and p38 MAPK, linked to BDNF that play a distinctive role in synaptic plasticity. We evaluated whether the effects of escitalopram on these targets may be different in brain areas involved in the depressive symptomatology (hippocampus, frontal and prefrontal cortex). Here we demonstrate that escitalopram regulates intracellular pathways linked to neuroplasticity at both the time points evaluated in an area-specific manner. While the two escitalopram-treatment regimens failed to affect gene expression in the rat frontal cortex, 7 days of treatment with escitalopram activated intracellular pathways linked to BDNF and increased the levels of Pro-BDNF in the rat prefrontal cortex. Moreover, 21 days of treatment with escitalopram decreased CREB/BDNF signalling while increasing p38 levels in the rat hippocampus. Even if further experiments with different antidepressant strategies will be needed, our data suggest that escitalopram efficacy may be mediated by early and late effects on synaptic plasticity in selective brain areas.

Distribution of estrogen receptor beta containing cells in the brains of bacterial artificial chromosome transgenic mice

In the brain, estrogen receptor β (ERβ) plays important roles in autonomic functions, stress reactivity and learning and memory processes. However, understanding the function of ERβ has been restricted by the limited availability of specific antisera, by difficulties discriminating the discrete localization of ERβ-immunoreactivity (ir) at the light microscopic level in many brain regions and the identification of ERβ-containing neurons in neurophysiological and molecular studies. Here, we demonstrate that a Esr2 bacterial artificial chromosome (BAC) transgenic mouse line that expresses ERβ identified by enhanced green fluorescent protein (EGFP) overcomes these shortcomings. Throughout the brain, ERβ-EGFP was detected in the nuclei and cytoplasm of cells, the majority of which resembled neurons. EGFP often extended into dendritic processes and could be identified either natively or following intensification of EGFP using immunolabeling. The distribution of ERβ-EGFP cells in brain closely corresponded to that reported for ERβ protein and mRNA. In particular, ERβ-EGFP cells were found in autonomic brain regions (i.e., hypothalamic paraventricular nucleus, rostral ventrolateral medulla and nucleus of the solitary tract), in regions associated with anxiety and stress behaviors (i.e., bed nucleus of the stria terminalis, amygdala, periaqueductal gray, raphe and parabrachial nuclei) and in regions involved in learning and memory processes (i.e., basal forebrain, cerebral cortex and hippocampus). Additionally, dual label light and electron microscopic studies in select brain areas demonstrate that cell containing ERβ-EGFP colocalize with both nuclear and extranuclear ERβ-immunoreactivity. These findings support the utility of Esr2 BAC transgenic reporter mice for future studies understanding the role of ERβ in CNS function.

Increased voluntary ethanol consumption and c-Fos expression in selected brain areas induced by fear memory retrieval in ethanol withdrawn rats

Withdrawal from chronic ethanol administration facilitated the formation of contextual fear memory. The effect of fear memory retrieval on subsequent ethanol consumption, by employing a two-bottle free-choice procedure with either water or ethanol (2-8% v/v), was investigated in ethanol withdrawn rats. The effect of fear memory extinction with or without d-cycloserine (DCS, 5mg/kgi.p.) on subsequent ethanol consumption was also evaluated. In addition, we examined c-Fos expression in different brain areas following the fear memory recall. The retrieval of such fear memory induced a significant increase in ethanol consumption in ethanol withdrawn but not in control animals. Regardless of DCS treatment, this increase was attenuated by extinction training. In ethanol withdrawn rats, context-dependent memory retrieval was accompanied by an increased c-Fos expression in the basolateral amygdala, ventrolateral periaqueductal gray, dentate gyrus and dorsomedial periaqueductal gray. Among these brain areas suggested to be implicated in the modulation of motivation and of emotional states, the basolateral amygdala has a crucial role in the emergence of negative affective state during ethanol withdrawal. These data suggest that retrieval of fear memory in ethanol withdrawn rats affected ethanol consumption and that amygdala may be involved in this effect.

Previous stress exposure enhances both anxiety-like behaviour and p35 levels in the basolateral amygdala complex: Modulation by midazolam

Stress exposure induces long lasting neurobiological changes in selected brain areas, which could be associated with the emergence of negative emotional responses. In the present study, previously restrained animals exhibited excessive anxiety one day later in the elevated plus maze. We explore whether stress exposure affects the expression levels of cyclin-dependent kinase 5 (Cdk5) and of its activator protein p35, in diverse amygdaloid nuclei. Stress exposure enhanced p35 levels selectively in the basolateral amygdala (BLA). This up-regulation might be functionally associated with the occurrence of exaggerated anxiety since such emotional response was selectively reversed by an intra-BLA infusion of olomoucine, a Cdk5 inhibitor, 15 min prior to the restraint session. Moreover, pre-treatment with midazolam, a benzodiazepine ligand, not only prevented the excessive anxiety but also attenuated the p35 increase in the BLA of stressed rats. In conclusion, we suggest a pivotal role of the Cdk5/p35 complex, specifically in BLA in the excessive anxiety induced by a previous stressful experience.

Gene expression profiling in C57BL/6J and A/J mouse inbred strains reveals gene networks specific for brain regions independent of genetic background

BackgroundWe performed gene expression profiling of the amygdala and hippocampus taken from inbred mouse strains C57BL/6J and A/J. The selected brain areas are implicated in neurobehavioral traits while these mouse strains are known to differ widely in behavior. Consequently, we hypothesized that comparing gene expression profiles for specific brain regions in these strains might provide insight into the molecular mechanisms of human neuropsychiatric traits. We performed a whole-genome gene expression experiment and applied a systems biology approach using weighted gene co-expression network analysis.ResultsWe were able to identify modules of co-expressed genes that distinguish a strain or brain region. Analysis of the networks that are most informative for hippocampus and amygdala revealed enrichment in neurologically, genetically and psychologically related pathways. Close examination of the strain-specific gene expression profiles, however, revealed no functional relevance but a significant enrichment of single nucleotide polymorphisms in the probe sequences used for array hybridization. This artifact was not observed for the modules of co-expressed genes that distinguish amygdala and hippocampus.ConclusionsThe brain-region specific modules were found to be independent of genetic background and are therefore likely to represent biologically relevant molecular networks that can be studied to complement our knowledge about pathways in neuropsychiatric disease.

3D-reconstructions and virtual 4D-visualization to study metamorphic brain development in the sphinx moth Manduca sexta

During metamorphosis, the transition from the larva to the adult, the insect brain undergoes considerable remodeling: new neurons are integrated while larval neurons are remodeled or eliminated. One well acknowledged model to study metamorphic brain development is the sphinx moth Manduca sexta. To further understand mechanisms involved in the metamorphic transition of the brain we generated a 3D standard brain based on selected brain areas of adult females and 3D reconstructed the same areas during defined stages of pupal development. Selected brain areas include for example mushroom bodies, central complex, antennal- and optic lobes. With this approach we eventually want to quantify developmental changes in neuropilar architecture, but also quantify changes in the neuronal complement and monitor the development of selected neuronal populations. Furthermore, we used a modeling software (Cinema 4D) to create a virtual 4D brain, morphing through its developmental stages. Thus the didactical advantages of 3D visualization are expanded to better comprehend complex processes of neuropil formation and remodeling during development. To obtain datasets of the M. sexta brain areas, we stained whole brains with an antiserum against the synaptic vesicle protein synapsin. Such labeled brains were then scanned with a confocal laser scanning microscope and selected neuropils were reconstructed with the 3D software AMIRA 4.1.

A Delayed Methadone Encephalopathy: Clinical and Neuroradiological Findings

Several studies on opiates demonstrated that selected brain areas as cerebellum and limbic system have the greatest density of opioid receptors. Recently, few cases of severe cerebellitis following methadone poisoning have been reported in children. We present the case of a 30-month-old girl who developed a delayed encephalopathy after methadone intoxication. She was admitted to our emergency department in coma, and after naloxone infusion, she completely recovered. Five days after intoxication, she developed psychomotor agitation, slurred speech, abnormal movements, and ataxia despite a negative neuroimaging finding. A repeat magnetic resonance imaging (MRI) performed 19 days after the intoxication for persistent symptoms showed signal abnormalities in the temporomesial regions, basal ganglia, and substantia nigra. To our knowledge, this is the first report of these delayed MRI findings associated with synthetic opioid intoxication.

Inverse correlation of brain and blood BDNF levels in a genetic rat model of depression

There is accumulating evidence that brain-derived neurotrophic factor (BDNF) plays a critical role in the pathophysiology of depression. Decreased serum levels have been reported in major depression, and a correlation between BDNF reduction and the severity of the disease was found. Moreover, in post-mortem hippocampal tissue, increased levels of BDNF immunoreactivity have been reported in subjects treated with antidepressants compared to untreated subjects. These findings indicate parallel changes in brain and serum BDNF levels during depression. BDNF has been measured in selected brain areas in several animal models. In investigations between Flinders Sensitive Line (FSL) and Flinders Resistant Line (FRL) rats, a genetic rat model of depression, no differences were found in BDNF levels in the frontal cortex and hippocampus, areas believed to be core brain regions in depression. However, to our knowledge brain and serum BDNF levels have never been reported in parallel for any psychiatric disease model. Therefore, we examined the levels of BDNF in whole blood, serum, cerebrospinal fluid (CSF), hippocampus, and frontal cortex in male FSL and FRL rats. BDNF levels in serum and whole blood of FSL rats were significantly increased compared to FRL rats. In contrast, in the hippocampus the BDNF level was significantly decreased in FSL compared to FRL rats while no differences were found in the frontal cortex and CSF. The differential regulation of the BDNF levels in hippocampus, serum, and whole blood in FSL/FRL rats adds to the hypothesis that neurotrophic factors are related to the pathophysiology of depression.

Experimental protocol for activation‐induced manganese‐enhanced MRI (AIM‐MRI) based on quantitative determination of Mn content in rat brain by fast T1 mapping

In activation-induced manganese-enhanced MRI (AIM-MRI) experiments, differential accumulation of Mn in activated and silent brain areas is generally assessed using T(1)-weighted images and quantified by the enhancement of signal intensity (SI), calculated with reference to SI before Mn administration or to SI of brain regions unaffected by the specific stimulus. However, SI enhancement can be unreliable when animals are removed from and reinserted into the magnet. We have developed an experimental protocol based on repeated intraperitoneal (i.p.) injections of Mn, quantitative determination of T(1), and coregistration of images to a rat brain atlas that allows absolute quantification of Mn concentration in selected brain areas. Results showed that interanimal variability of postcontrast T(1) values was very low (compared to the experimental error in T(1) determinations) allowing detection of differential regional Mn uptake in stimulated and unstimulated animals. In addition we have determined in vivo relaxivity of Mn in brain tissue and its frequency dependence.

Brain-region responsiveness to DT56a (Femarelle) administration on allopregnanolone and opioid content in ovariectomized rats

The natural selective estrogen receptor modulator DT56a (Femarelle), derived from soybean, has been shown to relieve menopausal vasomotor symptoms with no effect on sex steroid hormone levels or endometrial thickness.The purpose of the present study was to evaluate the neuroendocrine effect of DT56a administration through the evaluation of brain content of allopregnanolone (AP), an endogenous neurosteroid gamma-aminobutyric acid agonist with anxiolytic properties, and through the assessment of beta-endorphin (beta-END), the endogenous opioid implicated in pain mechanism, emotional state, and autonomic control. Five groups of Wistar ovariectomized (OVX) rats received one of the following treatments: oral DT56a administration at doses of 6, 12, 60, and 120 mg kg(-1) day(-1) or estradiol valerate (E2V) at a dose of 0.05 mg kg(-1) day(-1) for 14 days. One group of fertile and one group of OVX rats receiving placebo were used as controls. The concentration of AP was assessed in the frontal and parietal cortex, hippocampus, hypothalamus, anterior pituitary, and serum, whereas the content of beta-END was evaluated in the frontal and parietal cortex, hippocampus, hypothalamus, neurointermediate lobe, anterior pituitary, and plasma. DT56a increased AP levels in all brain areas analyzed and in serum, with a classical dose-related curve in comparison with OVX rats. In some brain areas, such as the frontal cortex, the parietal cortex, and the anterior pituitary, positive results were found even with the administration of a lower DT56a dose of 60 mg kg(-1) day(-1), attaining AP levels in the range of those in animals treated with E2V. Similarly, beta-END levels were enhanced in selected brain areas such as the hippocampus, the hypothalamus, the neurointermediate lobe, and the anterior pituitary in comparison with those in OVX rats, in which the increase of the opioid was dose related and in the range of those in rats treated with E2V. This study demonstrated that DT56a positively affects brain neurosteroidogenesis and the opiatergic system: DT56a exerts an estrogen-like effect on selective areas related to mood, cognition, and homeostasis control, presenting a specific pattern of interaction with the brain function. These findings may, in part, explain the clinical effect of DT56a on menopausal symptoms.

Corticotropin-releasing factor receptors: an overview.

Corticotropin-releasing factor (CRF) is the primary physiological regulator of basal and stress-induced release of ACTH, beta-endorphin and other POMC-derived peptides from the pituitary and plays a major role in the brain and periphery in coordinating endocrine, electrophysiological, autonomic, behavioral and immune responses to stress. In addition, recent clinical data implicate CRF in the etiology and pathophysiology in a variety of endocrine, psychiatric and neurodegenerative disorders. The various effects of CRF are mediated by two distinct CRF receptors expressed at high levels in selected brain areas, but also at different levels in several other non-neuronal tissues. This chapter provides an overview of the current knowledge about CRF receptors including tissue specificity and regulatory aspects as well as molecularbiological, biochemical and pharmacological characteristics. In addition, neuroimmune, neuroendocrine and behavioral-related implications of the CRF receptor as well as its involvement in a variety of disorders are discussed. This review summarizes four decades of research beginning with the search for the factor that governs the release of ACTH and getting to the recent findings including the successful cloning of different receptor subtypes and the discovery of a new endogenous CRF-related ligand.

A distinct pattern of intracellular glucocorticoid-related responses is associated with extreme behavioral response to stress in an animal model of post-traumatic stress disorder

Activation of glucocorticoid receptors (GR) increases expression of the mitogen-activated protein kinase (MAPK) pathway leading to increased expression of Zif/268, an effector immediate early gene involved in cellular growth, intracellular signaling, and synaptic modification. Glucocorticoids induce expression of Zif/268 through two distinct mechanisms: a rapid-onset, MAPK-independent pathway and a slower-onset, MAPK-dependent mechanism. This study investigated both rapid and long-term expression of GR protein in the cytosolic extract, its translocation to the nucleus, and expression of mRNA for the Zif/268 gene in selected brain areas, associated with circulating levels of corticosterone, in an animal model of PTSD. Trauma cue-triggered Zif/268 expression was assessed eight days after stress exposure. The results demonstrated a pattern of response that was common to all exposed individuals at 30 min after exposure, characterized by a significant elevation in GR translocation to the nucleus and elevated levels of Zif/268 mRNA in the hippocampus. A distinct pattern associated with extreme behavioral response (EBR) was revealed upon further bioassay of behavioral response groups, classified according to their individual patterns of behavioral response at seven days. These EBR individuals displayed significantly higher circulating corticosterone and nuclear GR levels, compared to minimal behavioral responders and controls. No difference in Zif/268 mRNA levels was observed between the exposed and naïve animals. Following the uniform acute response, the patterns of GR protein levels and Zif/268 mRNA levels are associated with degree of behavioral disruption. Since the slower-onset mechanism for glucocorticoid-induced Zif/268 expression depends on activation of the MAPK pathway, the pattern observed only in EBR rats may be related to disruptions of this pathway.

Central modifications of allopregnanolone and β-endorphin following subcutaneous administration of Nestorone

The aim of the present study was to evaluate the potential action of Nestorone (alone or in combination with estradiol valerate) on the level of allopregnanolone and of the opioid β-endorphin in selected brain areas. Wistar ovariectomized rats were given 0.05 mg/(kg day) of estradiol valerate (E2V) or subcutaneous Nestorone at three dose levels: low dose (10 μg/(kg day)), antiovulatory dose (50 μg/(kg day)) and high dose (250 μg/(kg day)) with and without E2V. E2V therapy reversed the reduction of allopregnanolone and β-endorphin induced by ovariectomy anywhere was analyzed except for the adrenal gland. Nestorone showed no effect on allopregnanolone concentration in serum or any part of the brain tissue when given alone while it had a synergistic increasing effect in allopregnanolone concentration in some parts of the brain (hippocampus, hypothalamus, anterior pituitary and serum) when given at high dose of 250 μg/(kg day) in combination with E2V. At lower doses it possesses a synergistic effect with E2V only in the hippocampus (at 50 μg/(kg day)) and in the anterior pituitary (at 10 and 50 μg/(kg day)). Nestorone administered alone at any dose led to significant increase in β-endorphin levels in the hippocampus only while, in the high dose group, there was a significant increase in endorphin levels in anterior pituitary and hypothalamus in addition to hippocampus as compared to ovariectomized control rats. In addition, only the highest dose of Nestorone added to estrogen increased β-endorphin levels of hippocampus and plasma. Thus the lower doses of Nestorone alone or in combination with estrogen do not seem to exert any great effect on both allopregnanolone and β-endorphin. It is only the highest dose of Nestorone that increases allopregnanolone and β-endorphin levels in selected brain areas, which are the hippocampus, the hypothalamus, the anterior pituitary and serum/plasma. This suggests that Nestorone at the antiovulatory dose levels may not alter the positive effects of estrogen treatment on mood and behaviour.

A fibre‐optic laser system and cell‐specific viral vectors for chronic opto‐genetic experimentation on deep brain structures

Optical control of neuronal circuits by light using expression of light‐activated ion channels such as channelrhodopsin‐2 in chronic unrestrained animals is a highly attractive method. ChR2 can be targeted to specific cellular types using viral vectors. However, convenient hardware solutions for delivery of the frequency and intensity‐modulated light pulses to the selected brain areas in a chronic experiment have to be developed. We present implantable optrodes which can be coupled to a "Deepstar" pulse‐modulated blue laser (445 nm, 50 mW, 1:100000 contrast ratio, Omicron, Germany) via a fine (200 μm core) flexible optical cable. The optrodes are manufactured of multimode quartz/quartz glass with metal coating and are secured to the optical cable with a miniature connector (A.R.T. Photonics). Optrodes with a 400 mkm core, outer diameter of 0.52 mm and NA of 0.22 have different lengths available for implantation (6‐14 mm). The fibre is coupled to the laser via an adjustable optical connector SMA‐905‐DS to allow precise focusing of the beam. Using this hardware we achieved light output from the optrodes at 36 ± 4 % (n=10) of the laser input power, this should be ample for any experiments involving stimulation of cells expressing ChR2. We have also generated several viral vectors which target ChR2 expression to different cell types in the CNS using cell‐specific transcriptionaly‐enhanced promoters.

Neuronal and Glial Alterations Due to Focal Cortical Hypoxia Induced by Direct Cobalt Chloride (CoCl2) Brain Injection

Ischemic brain injury is a dynamic process that involves oxidative stress, inflammation, and cell death, as well as activation of endogenous adaptive and regenerative mechanisms depending on activation of transcription factors such as hypoxia inducible factor 1-alpha (HIF-1alpha). Because CoCl2 activates HIF-1alpha, we described a new focal-hypoxia model by direct intracerebral CoCl2 injection. Adult male Wistar rats were intracerebrally injected with CoCl2 (2 microl-50 mM), in frontoparietal cortex of right hemisphere, and saline (2 microl) in the contralateral hemisphere. In slides of fixed brains at 1, 6, 9, 24 h or 5 day after treatment, TTC, histochemistry (toluidine blue, Hoescht-33342, TUNEL), immunostaining (HIF-1alpha, GFAP), Lycopersicon esculentum lectin staining, and electron microscopy (EM) were performed. Immediately after 1 h post CoCl2 injection, HIF-1alpha stabilization and neuronal nuclear shrinkage and cromathin condensation were observed by immunostaining and EM, respectively. Neuronal apoptotic nuclear morphology and GFAP immunoreactivity and lectin maximal reactivity were detected during 6-9 h. Ultrastructural alterations of morphology included edematous perinuclear cytoplasm, organelles and endoplasmic reticulum (RE) enlargement, mitochondrial swelling with increased matrix density, and deposits of electron-dense material. Neurons showed particular nuclear indentations. Astrocytes and oligodendrocytes presented alterations in both nuclei and RE with dilated lumen and altered mitochondrias, and all these ultrastructural changes became detectable at day 5. CoCl2 cortical injection mimics focal brain ischemia, inducing neuronal death and glial activation. This model brings the opportunity to develop focal ischemia in selected brain areas to study their functional consequences and potential pharmacological therapies for in vivo models of stroke.

Selective effect of chlormadinone acetate on brain allopregnanolone and opioids content

Background Synthetic progestins may have different biological actions depending on the target tissue, the dose administered or the coadministration of an estrogen molecule. The purpose of the present study was to evaluate the neuroendocrine effect of chlormadinone acetate (CMA) administration, analyzing the brain content of allopregnanolone (ALLO), an endogenous neurosteroid γ-aminobutyric acid agonist with anxiolytic properties, and the brain level of β-endorphin (β-END), an endogenous opioid implicated in pain mechanism, emotional state and autonomic control. Study Design Seven groups of Wistar ovariectomized (OVX) rats received one of the following treatments: oral CMA at a dose of 0.1, 0.5 or 1 mg/kg per day; estradiol valerate (E 2V) at a dose of 0.05 mg/kg per day; CMA plus E 2V (CMA 0.1 or 0.5 or 1 mg/kg per day + E 2V 0.05 mg/kg per day) for 14 days. One group of fertile rats and one group of OVX rats were used as controls. Results CMA increased ALLO content in the hippocampus and, when it was administered with E 2V, also in the hypothalamus and anterior pituitary, evidence of a synergic effect with estrogens only in selective brain areas. β-END content increased in the neurointermediate lobe and anterior pituitary after CMA administration, and it did not antagonize the positive, estrogen-induced increase of β-END level. Conclusion CMA is effective in increasing ALLO and β-END in selective brain areas showing a specific pattern of interaction with brain function, different compared to progesterone or to other synthetic progestins. In particular, CMA action on part of the limbic system (hippocampus and hypothalamus) and on the anterior pituitary support the hypothesis that this progestin might affect cognitive function, emotional state and autonomic control.

Expression profiles of urbilaterian genes uniquely shared between honey bee and vertebrates

BackgroundLarge-scale comparison of metazoan genomes has revealed that a significant fraction of genes of the last common ancestor of Bilateria (Urbilateria) is lost in each animal lineage. This event could be one of the underlying mechanisms involved in generating metazoan diversity. However, the present functions of these ancient genes have not been addressed extensively. To understand the functions and evolutionary mechanisms of such ancient Urbilaterian genes, we carried out comprehensive expression profile analysis of genes shared between vertebrates and honey bees but not with the other sequenced ecdysozoan genomes (honey bee-vertebrate specific, HVS genes) as a model.ResultsWe identified 30 honey bee and 55 mouse HVS genes. Many HVS genes exhibited tissue-selective expression patterns; intriguingly, the expression of 60% of honey bee HVS genes was found to be brain enriched, and 24% of mouse HVS genes were highly expressed in either or both the brain and testis. Moreover, a minimum of 38% of mouse HVS genes demonstrated neuron-enriched expression patterns, and 62% of them exhibited expression in selective brain areas, particularly the forebrain and cerebellum. Furthermore, gene ontology (GO) analysis of HVS genes predicted that 35% of genes are associated with DNA transcription and RNA processing.ConclusionThese results suggest that HVS genes include genes that are biased towards expression in the brain and gonads. They also demonstrate that at least some of Urbilaterian genes retained in the specific animal lineage may be selectively maintained to support the species-specific phenotypes.