scholarly journals Aromatase is pre-synaptic and sexually dimorphic in the adult zebra finch brain

2005 ◽  
Vol 272 (1576) ◽  
pp. 2089-2096 ◽  
Author(s):  
R. Scott Peterson ◽  
Lakshmi Yarram ◽  
Barney A Schlinger ◽  
Colin J Saldanha
Keyword(s):  
Zebra Finch ◽  
Brain Regions ◽  
Projection Neurons ◽  
Aromatase Activity ◽  
Sexually Dimorphic ◽  
Brain Areas ◽  
Synaptic Boutons ◽  
Caudomedial Nidopallium ◽  
Vertebrate Central Nervous System

Oestrogens organize and activate circuits within the vertebrate central nervous system. Oestrogen synthesis occurs via the expression of aromatase, a P 450 enzyme detected in microsomes and more recently in pre-synaptic boutons. Synaptic aromatase has only been described in brain regions that express aromatase in many subcellular compartments, so its function remains poorly understood. To more thoroughly study the role of oestrogen synthesis at synaptic terminals, we examined the ultrastructural compartmentalization of aromatase in the zebra finch; a species in which high aromatase activity can be measured in brain areas that do not contain somal aromatase. Here, we report the presence of aromatase in pre-synaptic boutons in the hippocampus and the high vocal centre brain areas with low and undetectable somal aromatase, respectively, in addition to areas with abundant somal aromatase such as the preoptic area and caudomedial nidopallium. At these brain areas, males had more total synapses, more aromatase pre-synaptic boutons and importantly, the proportion of total synaptic profiles that expressed aromatase was significantly higher in males relative to females. Aromatase-positive pre-synaptic boutons were always observed innervating aromatase-negative post-synaptic elements. We conclude that oestrogen may be provided to discrete oestrogen-sensitive targets by synaptic aromatization. Further, some targets may be exposed to more oestrogen in males. The expression of aromatase in individual synapses of projection neurons represents a unique mechanism of neuroendocrine action. Neurons with steroidogenic capability may modulate distant targets with the specificity of axonal innervation.

scholarly journals Osmotic Demyelination: From an Oligodendrocyte to an Astrocyte Perspective

2019 ◽  
Vol 20 (5) ◽  
pp. 1124 ◽  
Author(s):  
Charles Nicaise ◽  
Catherine Marneffe ◽  
Joanna Bouchat ◽  
Jacques Gilloteaux
Keyword(s):  
Glial Cells ◽  
Serum Sodium ◽  
Brain Regions ◽  
Osmotic Demyelination Syndrome ◽  
Brain Areas ◽  
Osmotic Demyelination ◽  
Central Myelin ◽  
Barrier Breakdown ◽  
Blood Brain Barrier Breakdown

Osmotic demyelination syndrome (ODS) is a disorder of the central myelin that is often associated with a precipitous rise of serum sodium. Remarkably, while the myelin and oligodendrocytes of specific brain areas degenerate during the disease, neighboring neurons and axons appear unspoiled, and neuroinflammation appears only once demyelination is well established. In addition to blood‒brain barrier breakdown and microglia activation, astrocyte death is among one of the earliest events during ODS pathology. This review will focus on various aspects of biochemical, molecular and cellular aspects of oligodendrocyte and astrocyte changes in ODS-susceptible brain regions, with an emphasis on the crosstalk between those two glial cells. Emerging evidence pointing to the initiating role of astrocytes in region-specific degeneration are discussed.

scholarly journals Effects of the alpha-1 antagonist prazosin on KOR agonist-induced reinstatement of alcohol seeking

2019 ◽  
Author(s):  
Douglas Funk ◽  
Kathleen Coen ◽  
Sahar Tamadon ◽  
A D Lê
Keyword(s):  
Stress Responses ◽  
Brain Activation ◽  
Brain Regions ◽  
Stress Disorders ◽  
Kappa Opioid Receptors ◽  
Brain Areas ◽  
Adrenoceptor Antagonist ◽  
Fos Expression ◽  
Alcohol Seeking

Abstract Background Stress is associated with relapse to alcohol seeking during abstinence, but the processes underlying this relationship are poorly understood. Noradrenaline is a key transmitter in stress responses and in stress-induced drug seeking. The alpha-1 adrenoceptor antagonist prazosin has been investigated as a treatment for alcoholism and for chronic stress disorders that are frequently comorbid with alcoholism. In rats, we previously showed that prazosin blocks reinstatement of alcohol seeking induced by footshock and yohimbine stressors, and reduces yohimbine-induced brain activation. The role of alpha-1 adrenoceptors in reinstatement induced by other stressors is not known. Our most recent work is on the role of kappa opioid receptors (KOR) in stress-induced reinstatement of alcohol seeking and have reported that the selective KOR agonist U50,488 induces reinstatement and neuronal activation in stress- and relapse-related brain regions. Here we determine the involvement of alpha-1 receptors in reinstatement and brain activation induced by U50,488. Methods We trained male Long-Evans rats to self-administer alcohol (12% w/v), extinguished alcohol-reinforced responding and then determined the effects of prazosin (1 mg/kg) on U50,488 (2.5 mg/kg)-induced reinstatement and regional Fos expression. Results Prazosin blocked U50,488-induced reinstatement and decreased U50,488-induced Fos expression in the OFC, NAC core, ventral BNST, CeA, BLA and VTA. Conclusions These findings suggest that prazosin may reduce U50,488-induced relapse by inhibiting activity in one or more of these brain areas.

Engaging regularly with fiction influences connectivity in cortical areas for language and mentalizing

2017 ◽  
Author(s):  
Roel M. Willems ◽  
Franziska Hartung
Keyword(s):  
Functional Connectivity ◽  
Time Course ◽  
Language Skills ◽  
Brain Regions ◽  
Brain Areas ◽  
Daily Lives ◽  
Cortical Areas ◽  
Social Abilities ◽  
Behavioral Evidence ◽  
Amount Of Reading

Behavioral evidence suggests that engaging with fiction is positively correlated with social abilities. The rationale behind this link is that engaging with fictional narratives offers a ‘training modus’ for mentalizing and empathizing. We investigated the influence of the amount of reading that participants report doing in their daily lives, on connections between brain areas while they listened to literary narratives. Participants (N=57) listened to two literary narratives while brain activation was measured with fMRI. We computed time-course correlations between brain regions, and compared the correlation values from listening to narratives to listening to reversed speech. The between-region correlations were then related to the amount of fiction that participants read in their daily lives. Our results show that amount of fiction reading is related to functional connectivity in areas known to be involved in language and mentalizing. This suggests that reading fiction influences social cognition as well as language skills.

scholarly journals Stoichiometric Analysis of Shifting in Subcellular Compartmentalization of HSP70 within Ischemic Penumbra

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3578
Author(s):  
Federica Mastroiacovo ◽  
Francesca Biagioni ◽  
Paola Lenzi ◽  
Larisa Ryskalin ◽  
Stefano Puglisi-Allegra ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Neuronal Survival ◽  
Hsp 70 ◽  
Preclinical Models ◽  
Brain Areas ◽  
Cell Compartments ◽  
Control Brain ◽  
Disease Modifier ◽  
Subcellular Compartmentalization

The heat shock protein (HSP) 70 is considered the main hallmark in preclinical studies to stain the peri-infarct region defined area penumbra in preclinical models of brain ischemia. This protein is also considered as a potential disease modifier, which may improve the outcome of ischemic damage. In fact, the molecule HSP70 acts as a chaperonine being able to impact at several level the homeostasis of neurons. Despite being used routinely to stain area penumbra in light microscopy, the subcellular placement of this protein within area penumbra neurons, to our knowledge, remains undefined. This is key mostly when considering studies aimed at deciphering the functional role of this protein as a determinant of neuronal survival. The general subcellular placement of HSP70 was grossly reported in studies using confocal microscopy, although no direct visualization of this molecule at electron microscopy was carried out. The present study aims to provide a direct evidence of HSP70 within various subcellular compartments. In detail, by using ultrastructural morphometry to quantify HSP70 stoichiometrically detected by immuno-gold within specific organelles we could compare the compartmentalization of the molecule within area penumbra compared with control brain areas. The study indicates that two cell compartments in control conditions own a high density of HSP70, cytosolic vacuoles and mitochondria. In these organelles, HSP70 is present in amount exceeding several-fold the presence in the cytosol. Remarkably, within area penumbra a loss of such a specific polarization is documented. This leads to the depletion of HSP70 from mitochondria and mostly cell vacuoles. Such an effect is expected to lead to significant variations in the ability of HSP70 to exert its physiological roles. The present findings, beyond defining the neuronal compartmentalization of HSP70 within area penumbra may lead to a better comprehension of its beneficial/detrimental role in promoting neuronal survival.

scholarly journals The G Protein-Coupled Glutamate Receptors as Novel Molecular Targets in Schizophrenia Treatment—A Narrative Review

2021 ◽  
Vol 10 (7) ◽  
pp. 1475
Author(s):  
Waldemar Kryszkowski ◽  
Tomasz Boczek
Keyword(s):  
Glutamate Receptors ◽  
Metabotropic Glutamate Receptors ◽  
Glutamate Release ◽  
Molecular Targets ◽  
Brain Regions ◽  
Psychotic Symptoms ◽  
Unknown Etiology ◽  
Metabotropic Glutamate ◽  
G Protein Coupled

Schizophrenia is a severe neuropsychiatric disease with an unknown etiology. The research into the neurobiology of this disease led to several models aimed at explaining the link between perturbations in brain function and the manifestation of psychotic symptoms. The glutamatergic hypothesis postulates that disrupted glutamate neurotransmission may mediate cognitive and psychosocial impairments by affecting the connections between the cortex and the thalamus. In this regard, the greatest attention has been given to ionotropic NMDA receptor hypofunction. However, converging data indicates metabotropic glutamate receptors as crucial for cognitive and psychomotor function. The distribution of these receptors in the brain regions related to schizophrenia and their regulatory role in glutamate release make them promising molecular targets for novel antipsychotics. This article reviews the progress in the research on the role of metabotropic glutamate receptors in schizophrenia etiopathology.

scholarly journals The Role of Sonic Hedgehog-Gli2 Pathway in the Masculinization of External Genitalia

Endocrinology ◽  
2011 ◽  
Vol 152 (7) ◽  
pp. 2894-2903 ◽  
Author(s):  
Shinichi Miyagawa ◽  
Daisuke Matsumaru ◽  
Aki Murashima ◽  
Akiko Omori ◽  
Yoshihiko Satoh ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Sonic Hedgehog ◽  
Hedgehog Signaling ◽  
External Genitalia ◽  
Sexually Dimorphic ◽  
Hedgehog Signaling Pathway ◽  
Initial Development ◽  
Urethral Plate ◽  
Male External Genitalia

During embryogenesis, sexually dimorphic organogenesis is achieved by hormones produced in the gonad. The external genitalia develop from a single primordium, the genital tubercle, and their masculinization processes depend on the androgen signaling. In addition to such hormonal signaling, the involvement of nongonadal and locally produced masculinization factors has been unclear. To elucidate the mechanisms of the sexually dimorphic development of the external genitalia, series of conditional mutant mouse analyses were performed using several mutant alleles, particularly focusing on the role of hedgehog signaling pathway in this manuscript. We demonstrate that hedgehog pathway is indispensable for the establishment of male external genitalia characteristics. Sonic hedgehog is expressed in the urethral plate epithelium, and its signal is mediated through glioblastoma 2 (Gli2) in the mesenchyme. The expression level of the sexually dimorphic genes is decreased in the glioblastoma 2 mutant embryos, suggesting that hedgehog signal is likely to facilitate the masculinization processes by affecting the androgen responsiveness. In addition, a conditional mutation of Sonic hedgehog at the sexual differentiation stage leads to abnormal male external genitalia development. The current study identified hedgehog signaling pathway as a key factor not only for initial development but also for sexually dimorphic development of the external genitalia in coordination with androgen signaling.

scholarly journals The Protective Role of Brain CYP2J in Parkinson’s Disease Models

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yueran Li ◽  
Jinhua Wu ◽  
Xuming Yu ◽  
Shufang Na ◽  
Ke Li ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Brain Regions ◽  
Protective Role ◽  
Neural Cells ◽  
Endogenous Substrates ◽  
6 Hydroxydopamine ◽  
Myd88 Signaling ◽  
Lps Treatment

CYP2J proteins are present in the neural cells of human and rodent brain regions. The aim of this study was to investigate the role of brain CYP2J in Parkinson’s disease. Rats received right unilateral injection with lipopolysaccharide (LPS) or 6-hydroxydopamine (6-OHDA) in the substantia nigra following transfection with or without the CYP2J3 expression vector. Compared with LPS-treated rats, CYP2J3 transfection significantly decreased apomorphine-induced rotation by 57.3% at day 12 and 47.0% at day 21 after LPS treatment; moreover, CYP2J3 transfection attenuated the accumulation of α-synuclein. Compared with the 6-OHDA group, the number of rotations by rats transfected with CYP2J3 decreased by 59.6% at day 12 and 43.5% at day 21 after 6-OHDA treatment. The loss of dopaminergic neurons and the inhibition of the antioxidative system induced by LPS or 6-OHDA were attenuated following CYP2J3 transfection. The TLR4-MyD88 signaling pathway was involved in the downregulation of brain CYP2J induced by LPS, and CYP2J transfection upregulated the expression of Nrf2 via the inhibition of miR-340 in U251 cells. The data suggest that increased levels of CYP2J in the brain can delay the pathological progression of PD initiated by inflammation or neurotoxins. The alteration of the metabolism of the endogenous substrates (e.g., AA) could affect the risk of neurodegenerative disease.

Electroencephalographic Recordings of Focal Seizures in Patients Affected by Periventricular Nodular Heterotopia: Role of the Heterotopic Nodules in the Genesis of Epileptic Discharges

2004 ◽  
Vol 19 (3) ◽  
pp. 369-377
Author(s):  
Giorgio Battaglia ◽  
Silvana Franceschetti ◽  
Luisa Chiapparini ◽  
Elena Freri ◽  
Stefania Bassanini ◽  
...  
Keyword(s):  
Brain Regions ◽  
Periventricular Nodular Heterotopia ◽  
Focal Seizures ◽  
Ictal Eeg ◽  
Epileptic Discharges ◽  
Nodular Heterotopia ◽  
Eeg Recordings ◽  
Drug Resistant Epilepsy ◽  
Video Eeg

Patients affected by periventricular nodular heterotopia are frequently characterized by focal drug-resistant epilepsy. To investigate the role of periventricular nodules in the genesis of seizures, we analyzed the electroencephalographic (EEG) features of focal seizures recorded by means of video-EEG in 10 patients affected by different types of periventricular nodular heterotopia and followed for prolonged periods of time at the epilepsy center of our institute. The ictal EEG recordings with surface electrodes revealed common features in all patients: all seizures originated from the brain regions where the periventricular nodular heterotopia were located; EEG patterns recorded on the leads exploring the periventricular nodular heterotopia were very similar both at the onset and immediately after the seizure's end in all patients. Our data suggest that seizures are generated by abnormal anatomic circuitries, including the heterotopic nodules and adjacent cortical areas. The major role of heterotopic neurons in the genesis and propagation of epileptic discharges must be taken into account when planning surgery for epilepsy in patients with periventricular nodular heterotopia. ( J Child Neurol 2005;20:369—377).

Carotenoid-based plumage colouration in red bishops (Euplectes orix) — signalling presence rather than quality?

Behaviour ◽  
2011 ◽  
Vol 148 (11-13) ◽  
pp. 1372-1392 ◽  
Author(s):  
Alice U. Edler ◽  
Thomas W.P. Friedl
Keyword(s):  
Reproductive Success ◽  
Parasite Load ◽  
Blood Parasite ◽  
Male Reproductive Success ◽  
Sexually Dimorphic ◽  
Male Quality ◽  
Plumage Colouration ◽  
Selection For ◽  
Breeding Plumage

AbstractThe role of bright plumage colouration for female choice has been the focus of research in sexual selection for many years, with several studies showing that females prefer the most elaborately ornamented males, which are often also the highest quality individuals. Here, we analysed the associations between reproductive performance and plumage, body condition and blood parasite load in the red bishop (Euplectes orix), a sexually dimorphic and polygynous weaverbird species, where males in a carotenoid-based orange-to-red breeding plumage defend territories and build many nests to which they try to attract females. Male reproductive success in terms of number of nests accepted was mainly determined by the number of nests built, but was also positively related to blood parasite load, while we found no influence of plumage characteristics. Together with previously obtained data, our results indicate that plumage characteristics in the red bishop do not affect male reproductive success and are generally not suitable to reliably indicate male quality. We suggest that the primary function of the brilliant orange-scarlet breeding plumage might be presence signalling in terms of increasing conspicuousness of breeding males to females searching for mates.

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