Enhanced Synaptic Integration of Adult-Born Neurons in the Olfactory Bulb of Lactating Mothers
ABSTRACT One of the most dramatic events during the life of adult mammals is the transition into motherhood. This transition is accompanied by specific maternal behaviors, displayed by the mother, that ensure the survival and the well-being of her offspring. The execution of these behaviors is most likely accompanied by plastic changes in specific neuronal circuits, but these are still poorly defined. In this work, we studied the mammalian olfactory bulb (OB), which has been shown to be an essential brain region for maternal behaviors in mice. In the OB, we focused on adult-born neurons, which are continuously incorporated into the circuit during adulthood, thus providing a potential substrate for heightened plasticity after parturition. We analyzed the dynamics and morphological characteristics of adult-born granule cells (abGCs), innervating the OB of primiparous lactating mothers, shortly after parturition as well as in naive females. In vivo time-lapse imaging of abGCs revealed that dendritic spines were significantly more stable in lactating mothers compared with naive virgins. In contrast, spine stability of resident GCs remained unchanged after parturition. In addition, while spine size distribution of abGCs was approximately similar between mothers and naive virgins, the spine density of abGCs was lower in lactating mothers and the density of their presynaptic components was higher. These structural features are indicative of enhanced integration of adult-born neurons into the bulbar circuitry of lactating mothers. This enhanced integration may serve as a cellular mechanism, supporting changes in olfactory coding of new mothers during their first days following parturition.
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ABSTRACT: Parental care, including feeding and protection of young, is essential for the survival as well as mental and physical well-being of the offspring. A large variety of parental behaviors has been described across species and sexes, raising fascinating questions about how animals identify the young and how brain circuits drive and modulate parental displays in males and females. Recent studies have begun to uncover a striking antagonistic interplay between brain systems underlying parental care and infant-directed aggression in both males and females, as well as a large range of intrinsic and environmentally driven neural modulation and plasticity. Improved understanding of the neural control of parental interactions in animals should provide novel insights into the complex issue of human parental care in both health and disease.Science 08/2014; 345(6198):765-770. DOI:10.1126/science.1253291 · 31.48 Impact Factor
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ABSTRACT: Juxtaglomerular neurons (JGNs) of the mammalian olfactory bulb are generated throughout life. Their integration into the preexisting neural network, their differentiation and survival therein depend on sensory activity, but when and how these adult-born cells acquire responsiveness to sensory stimuli remains unknown. In vivo two-photon imaging of retrovirally labelled adult-born JGNs reveals that ~90% of the cells arrive at the glomerular layer after day post injection (DPI) 7. After arrival, adult-born JGNs are still migrating, but at DPI 9, 52% of them have odour-evoked Ca(2+) signals. Their odourant sensitivity closely resembles that of the parent glomerulus and surrounding JGNs, and their spontaneous and odour-evoked spiking is similar to that of their resident neighbours. Our data reveal a remarkably rapid functional integration of adult-born cells into the preexisting neural network. The mature pattern of odour-evoked responses of these cells strongly contrasts with their molecular phenotype, which is typical of immature, migrating neuroblasts.Nature Communications 02/2015; 6:6349. DOI:10.1038/ncomms7349 · 10.74 Impact Factor
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ABSTRACT: Artículos Maduración neuronal durante el desarrollo embrionario tardío y postnatal temprano del bulbo olfatorio de ratón Introducción Materiales y métodos Resultados Discusión Referencias Delsy Dávila-Vera firstname.lastname@example.org Neurociencia Maduración neuronal durante el desarrollo embrionario tardío y postnatal temprano del bulbo olfatorio de ratón Fecha de recepción: 19/06/2013 Fecha de aceptación: 25/11/2013 El bulbo olfatorio desempeña importantes funciones como centro de enlace entre el medio ambiente y los centros cerebrales superiores, siendo conocida su participación en alteraciones neurológicas, genéticas y hepáticas. De allí el objetivo de estudiar la neurodiferenciación del bulbo olfatorio durante el desarrollo prenatal (E) tardío y el postnatal (P) temprano en ratones NMRI utilizando microscopía de luz y electrónica, para lograr una mejor comprensión de su funcionalidad. Las células neuronales al día E13 son inmaduras, progresivamente se van diferenciando y ubicando según los diversos tipos celulares, definiéndose la organización laminar al momento del nacimiento. En la etapa postnatal temprana se consolida la histotipia del bulbo olfatorio, alcanzando al día P7 la madurez histológica y sináptica. Las sinapsis axo-dendríticas se observan desde la fase prenatal mientras que las dendro-dendríticas son una expresión morfo-funcional postnatal. Estos resultados permiten futuras propuestas experimentales sobre enfermedades que involucran al bulbo olfatorio. Palabras Claves:Bulbo olfatorio; diferenciación neuronal; formación sináptica; ultraestructura. Title Neuronal maturation during late embryonic and early postnatal development of Mouse olfactory bulb Abstract The olfactory bulb plays an important role as a link between the environment and higher brain centers, This structure is known for its role in neurological, genetic and liver disorders. Hence the aim of studying the neuronal differentiation during late embryonic (E) and early postnatal (P) development of NMRI mice olfactory bulb, using light and electron microscopy, to achieve a better understanding of its functionality. Neuronal cells at day E13 were immature, progressively they differentiate and migrate according to the different cell types, so that a defined laminar organization could be appreciated at birth. In early postnatal stage histotypic organization was consolidated, reaching at day P7 histological and synaptic maturity. The axo-dendritic synapses were observed from the embryonic stage, whereas dendro-dendritic were only seen in the postnatal stage.Vitae 11/2013; · 0.26 Impact Factor