25 research outputs found

    The Mouse Primary Visual Cortex Is a Site of Production and Sensitivity to Estrogens

    Get PDF
    The classic female estrogen, 17Ī²-estradiol (E2), has been repeatedly shown to affect the perceptual processing of visual cues. Although gonadal E2 has often been thought to influence these processes, the possibility that central visual processing may be modulated by brain-generated hormone has not been explored. Here we show that estrogen-associated circuits are highly prevalent in the mouse primary visual cortex (V1). Specifically, we cloned aromatase, a marker for estrogen-producing neurons, and the classic estrogen receptors (ERs) ERĪ± and ERĪ², as markers for estrogen-responsive neurons, and conducted a detailed expression analysis via in-situ hybridization. We found that both monocular and binocular V1 are highly enriched in aromatase- and ER-positive neurons, indicating that V1 is a site of production and sensitivity to estrogens. Using double-fluorescence in-situ hybridization, we reveal the neurochemical identity of estrogen-producing and -sensitive cells in V1, and demonstrate that they constitute a heterogeneous neuronal population. We further show that visual experience engages a large population of aromatase-positive neurons and, to a lesser extent, ER-expressing neurons, suggesting that E2 levels may be locally regulated by visual input in V1. Interestingly, acute episodes of visual experience do not affect the density or distribution of estrogen-associated circuits. Finally, we show that adult mice dark-reared from birth also exhibit normal distribution of aromatase and ERs throughout V1, suggesting that the implementation and maintenance of estrogen-associated circuits is independent of visual experience. Our findings demonstrate that the adult V1 is a site of production and sensitivity to estrogens, and suggest that locally-produced E2 may shape visual cortical processing

    Human branch point consensus sequence is yUnAy

    Get PDF
    Yeast carries a strictly conserved branch point sequence (BPS) of UACUAAC, whereas the human BPS is degenerative and is less well characterized. The human consensus BPS has never been extensively explored in vitro to date. Here, we sequenced 367 clones of lariat RT-PCR products arising from 52 introns of 20 human housekeeping genes. Among the 367 clones, a misincorporated nucleotide at the branch point was observed in 181 clones, for which we can precisely pinpoint the branch point. The branch points were comprised of 92.3% A, 3.3% C, 1.7% G and 2.8% U. Our analysis revealed that the human consensus BPS is simply yUnAy, where the underlined is the branch point at position zero and the lowercase pyrimidines (ā€˜yā€™) are not as well conserved as the uppercase U and A. We found that the branch points are located 21ā€“34 nucleotides upstream of the 3ā€² end of an intron in 83% clones. We also found that the polypyrimidine tract spans 4ā€“24 nucleotides downstream of the branch point. Our analysis demonstrates that the human BPSs are more degenerative than we have expected and that the human BPSs are likely to be recognized in combination with the polypyrimidine tract and/or the other splicing cis-elements

    Organization of estrogen-associated circuits in the mouse primary auditory cortex

    No full text
    Ā© the author(s). Sex steroid hormones influence the perceptual processing of sensory signals in vertebrates. In particular, decades of research have shown that circulating levels of estrogen correlate with hearing function. The mechanisms and sites of action supporting this sensory-neuroendocrine modulation, however, remain unknown. Here we combined a molecular cloning strategy, fluorescence in-situ hybridization and unbiased quantification methods to show that estrogen-producing and -sensitive neurons heavily populate the adult mouse primary auditory cortex (AI). We also show that auditory experience in freely-behaving animals engages estrogen-producing and -sensitive neurons in AI. These estrogen-associated networks are greatly stable, and do not quantitatively change as a result of acute episodes of sensory experience. We further demonstrate the neurochemical identity of estrogen-producing and estrogen-sensitive neurons in AI and show that these cell populations are phenotypically distinct. Our findings provide the first direct demonstration that estrogen-associated circuits are highly prevalent and engaged by sensory experience in the mouse auditory cortex, and suggest that previous correlations between estrogen levels and hearing function may be related to brain-generated hormone production. Finally, our findings suggest that estrogenic modulation may be a central component of the operational framework of central auditory networks

    Expression And Rapid Experienceā€Dependent Regulation Of Typeā€A Gabaergic Receptors In The Songbird Auditory Forebrain

    No full text
    GABAergic transmission influences sensory processing and experience-dependent plasticity in the adult brain. Little is known about the functional organization of inhibitory circuits in the auditory forebrain of songbirds, a robust model extensively used in the study of central auditory processing of behaviorally relevant communication signals. In particular, no information is currently available on the expression and organization of GABAA receptor-expressing neurons. Here, we studied the distribution and regulation of GABAA receptors in the songbird auditory forebrain, with a specific focus on Ī±5, a subunit implicated in tonic inhibition and sensory learning. We obtained a zebra finch cDNA that encodes the Ī±5-subunit (GABRA5) and carried out a detailed analysis of its expression via in situ hybridization. GABRA5 was highly expressed in the caudomedial nidopallium (NCM), caudomedial mesopallium, and field L2. Using double fluorescence in situ hybridization, we demonstrate that a large fraction of GABRA5-expressing neurons is engaged by auditory experience, as revealed by the song-induced expression of the activity-dependent gene zenk. Remarkably, we also found that Ī±5 expression is rapidly regulated by sensory stimulation: 30 min of conspecific song playbacks significantly increase the number of GABRA5-expressing neurons in NCM, but not in other auditory areas. This effect is selective for Ī±5, but not Ī³2 transcripts. Our results suggest that Ī±5-containing GABAA receptors likely play a key role in central auditory processing and may contribute to the experience-dependent plasticity underlying auditory learning

    Mechanistic basis and functional roles of long-term plasticity in auditory neurons induced by a brain-generated estrogen

    No full text
    The classic estrogen 17Ī²-estradiol (E2) was recently identified as a novel modulator of hearing function. It is produced rapidly, in an experience-dependent fashion, by auditory cortical neurons of both males and females. This brain-generated E2 enhances the efficiency of auditory coding and improves the neural and behavioral discrimination of auditory cues. Remarkably, the effects of E2 are long-lasting and persist for hours after local rises in hormone levels have subsided. The mechanisms and functional consequences of this E2-induced plasticity of auditory responses are unknown. Here, we addressed these issues in the zebra finch model by combining intracerebral pharmacology, biochemical assays, in vivo neurophysiology in awake animals, and computational and information theoretical approaches. Weshow that auditory experience activates the MAPK pathway in an E2-dependent manner. This effect is mediated by estrogen receptor Ī² (ERĪ²), which directly associates with MEKK1 to sequentially modulate MEK and ERK activation, where the latter is required for the engagement of downstream molecular targets. We further show that E2-mediated activation of the MAPK cascade is required for the long-lasting enhancement of auditory-evoked responses in the awake brain. Moreover, a functional consequence of this E2/MAPK activation is to sustain enhanced information handling and neural discrimination by auditory neurons for several hours following hormonal challenge. Our results demonstrate that brain-generated E2 engages, via a nongenomic interaction between an estrogen receptor and a kinase, a persistent form of experience-dependent plasticity that enhances the neural coding and discrimination of behaviorally relevant sensory signals in the adult vertebrate brain. Ā©2012 the authors

    Chronic visual deprivation, from birth to adulthood, does not affect the density of estrogen-associated circuits in V1.

    No full text
    <p>Shown are the mean numerical densities (Ā± S.E.) of cells that are positive for ARO-, ERĪ±- and ERĪ²-positive in the V1 of control (normally-raised) and light-deprived adult mice. Data is shown for supragranular, granular and infragranular layers separately. Light-deprived animals were born and kept in complete darkness until adulthood (see Methods). No differences were detected for ARO-, ERĪ±- or ERĪ², for any cortical layers, when comparing control and chronically light-deprived animals.</p

    Depression-Related Increases and Decreases in Appetite: Dissociable Patterns of Aberrant Activity in Reward and Interoceptive Neurocircuitry

    Full text link
    Estructura del pĆ”rrafoSe explicarĆ” la forma correcta de escribir un pĆ”rrafo, sus funciones y tipos.IntroducciĆ³n - Tipos de pĆ”rrafos- FunciĆ³n de los pĆ”rrafos- Ejercicio-BibliografĆ­a.1.

    The primary visual cortex (V1) contains a large population of estrogen-producing and estrogen-producing neurons.

    No full text
    <p>Aā€“C) Low-power photomicrographs depicting fluorescence in-situ hybridization directed against the mRNAs encoded by ARO (A), ERĪ± (D) and ERĪ² (C) in V1. Each of these mRNAs is expressed at relatively high levels in all cortical laminae, except for layer I. Dā€“F) Representative high power photomicrographs illustrating the labeling pattern for ARO (D), ERĪ± (E) and ERĪ² (F) in the supragranular layers (II/III) of V1. The labeling pattern in the granular and infragranular layers was identical to that detected in the supragranular layers and, consequently, is not shown here. In-situ hybridization conducted with sense strand riboprobes did not reveal labeling for any of our genes of interest (data not shown). Photomicrographs were obtained with epifluorescence (Aā€“C) and confocal (Dā€“F) microscopy. Scale bars: Aā€“Cā€Š=ā€Š100 Āµm; Dā€“Fā€Š=ā€Š25 Āµm.</p
    corecore