22 research outputs found

    A connectome and analysis of the adult Drosophila central brain.

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    The neural circuits responsible for animal behavior remain largely unknown. We summarize new methods and present the circuitry of a large fraction of the brain of the fruit fly Drosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses in, and proofread such large data sets. We define cell types, refine computational compartments, and provide an exhaustive atlas of cell examples and types, many of them novel. We provide detailed circuits consisting of neurons and their chemical synapses for most of the central brain. We make the data public and simplify access, reducing the effort needed to answer circuit questions, and provide procedures linking the neurons defined by our analysis with genetic reagents. Biologically, we examine distributions of connection strengths, neural motifs on different scales, electrical consequences of compartmentalization, and evidence that maximizing packing density is an important criterion in the evolution of the fly's brain

    Estrogen Receptor Ī² Is Required for Optimal cAMP Production in Mouse Granulosa Cells

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    Granulosa cells of preovulatory follicles differentiate in response to FSH, and this differentiation is augmented by estradiol. We have previously shown that FSH-mediated granulosa cell differentiation requires functional estrogen receptor-Ī² (ERĪ²) by demonstrating that the granulosa cells of ERĪ²āˆ’/āˆ’ FSH-treated mice are unable to maximally induce expression of the LH receptor (an indicator of granulosa cell differentiation) compared with ERĪ²+/+ controls. As a result, FSH-primed ERĪ²āˆ’/āˆ’ granulosa cells exhibit a reduced response to a subsequent ovulatory dose of LH. In this study, we further characterized the attenuated response of ERĪ²āˆ’/āˆ’ granulosa cells to stimulation by LH and FSH using isolated mouse granulosa cells and primary granulosa cell cultures. We observed a 50% reduction in cAMP levels in cultured ERĪ²āˆ’/āˆ’ granulosa cells exposed to LH compared with ERĪ²+/+ controls. We also observed an attenuated genomic response in granulosa cells isolated from FSH-primed ERĪ²āˆ’/āˆ’ mice compared with ERĪ²+/+ controls. Our data indicate that this attenuated response may result from inadequate levels of cAMP, because cAMP levels in cultured ERĪ²āˆ’/āˆ’ granulosa cells exposed to forskolin were approximately 50% lower than in ERĪ²+/+ granulosa cells. Phosphorylation of cAMP regulatory element binding protein, an indicator of protein kinase A activity, was also reduced in FSH-treated ERĪ²āˆ’/āˆ’ granulosa cells compared with ERĪ²+/+ controls. These are the first data to indicate that ERĪ² plays a role in the induction of the cAMP pathway in mouse granulosa cells and that disruption of proper ERĪ² signaling associated with this pathway may cause negative effects on ovulation and fertility
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