Prevention of age-related dysregulation of calcium dynamics by estrogen in neurons

Brewer, Gregory J.; Reichensperger, Joel; Brinton, Roberta Dı́az

doi:10.1016/j.neurobiolaging.2005.01.019

Cited by 58 publications

(61 citation statements)

References 47 publications

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“…Faster termination of excitatory signals likely enables faster spike rates with shorter refractory periods. One of the NbActiv4 components, estrogen, promotes better handling of calcium signals (Kumar & Foster, 2002;Brewer et al, 2006). Estrogen also limits voltage-gated calcium channel conductances (Kumar & Foster, 2002) and inhibits the mitochondrial permeability transition by increasing Bcl-2 in mitochondria (Brinton et al, 1997;Nilsen & Brinton, 2003;Nilsen et al, 2002).…”

Section: Discussionmentioning

confidence: 99%

“…We report here low spontaneous spike rates of <0.5 Hz (spikes/sec) that develop in Neurobasal/B27 medium that can be improved 4 to 8-fold with certain additions to this classic medium. Additions that were optimized include cholesterol, shown to promote synaptogenesis (Pfrieger & Barres, 1997;Goritz et al, 2005), estrogen, to control better handling of the calcium influx (Kumar & Foster, 2002;Brewer et al, 2006), and creatine as an energy precursor for phosphocreatine to empower greater spike rates (Brewer & Wallimann, 2000) and possibly induce more inhibitory synapses (Ducray et al, 2007). The resulting optimized medium, NbActiv4, appears to promote higher spike rates by a mechanism involving greater synaptogenesis.…”

Section: Introductionmentioning

confidence: 99%

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NbActiv4 medium improvement to Neurobasal/B27 increases neuron synapse densities and network spike rates on multielectrode arrays

Brewer

Boehler

Jones

et al. 2008

Journal of Neuroscience Methods

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The most interesting property of neurons is their long-distance propagation of signals as spiking action potentials. Since 1993, Neurobasal/B27 ™ has been used as a serum-free medium optimized for hippocampal neuron survival. Neurons on microelectrode arrays (MEA) were used as an assay system to increase spontaneous spike rates in media of different compositions. We find spike rates of 0.5/second (Hz) for rat embryonic hippocampal neurons cultured in Neurobasal/B27, lower than cultures in serum-based media and offering an opportunity for improvement. NbActiv4™ was formulated by addition of creatine, cholesterol and estrogen to Neurobasal/B27 that synergistically produced an 8-fold increase in spontaneous spike activity. The increased activity with NbActiv4 correlated with a 2-fold increase in immunoreactive synaptophysin bright puncta and GluR1 total puncta. Characteristic of synaptic scaling, immunoreactive GABA Aβ puncta also increased 1.5-fold and NMDA-R1 puncta increased 1.8-fold. Neuron survival in NbActiv4 equaled that in Neurobasal/ B27, but with slightly higher astroglia. Resting respiratory demand was decreased and demand capacity was increased in NbActiv4, indicating less stress and higher efficiency. These results show that NbActiv4 is an improvement to Neurobasal/B27 for cultured networks with an increased density of synapses and transmitter receptors which produces higher spontaneous spike rates in neuron networks.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

NbActiv4 medium improvement to Neurobasal/B27 increases neuron synapse densities and network spike rates on multielectrode arrays

Brewer

Boehler

Jones

et al. 2008

Journal of Neuroscience Methods

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“…Primary cultures of cortical neurons were obtained from embryonic day 18 rat fetuses as described previously (Nilsen and Brinton, 2003b;Brewer et al, 2006). Briefly, cortical cells were dissected and treated with 0.02% trypsin in HBSS (Invitrogen) for 5 min at 37°C and dissociated by repeated passage through a series of fire-polished constricted Pasteur pipettes.…”

Section: Methodsmentioning

confidence: 99%

“…Neurons were grown in Neurobasal medium (Invitrogen) supplemented with 10 U/ml penicillin, 10 g/ml streptomycin, 0.5 mM glutamine, 25 M glutamate, and 2% B27 (Invitrogen). These culture conditions are well established in multiple laboratories, including our own, to generate cultures that are Ͼ95% neuronal and Յ5% glial (Brewer et al, 2006). Cultures were maintained at 37°C in a humidified 5% CO 2 atmosphere.…”

Section: Methodsmentioning

confidence: 99%

Estrogen Receptor Protein Interaction with Phosphatidylinositol 3-Kinase Leads to Activation of Phosphorylated Akt and Extracellular Signal-Regulated Kinase 1/2 in the Same Population of Cortical Neurons: A Unified Mechanism of Estrogen Action

Mannella¹,

Brinton²

2006

J. Neurosci.

190

189

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17␤-Estradiol (E 2 )-induced neuroprotection is dependent on mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3-kinase (PI3K) signaling cascades. We sought to determine whether E 2 neuroprotective mechanisms are mediated by a unified signaling cascade activated by estrogen receptor (ER)-PI3K interaction within the same population of neurons or whether E 2 activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and Akt are independent signaling events in different neuronal populations. Immunoprecipitation of E 2 -treated cortical neurons was conducted to determine a protein-protein interaction between ER and the PI3K regulatory subunit p85. Subsequently, cortical neurons were treated with E 2 alone or in presence of MAPK inhibitors or PI3K inhibitors. Results of these analyses indicated a protein-protein interaction between ER and p85 that was time-dependent and consistent with the temporal profile for generation of Akt (pAkt) and ERK1/2 phosphorylation (pERK1/2). E 2 -induced phosphorylation of Akt, was first apparent at 10 min and maximal at 30 min. Simultaneously, E 2 -induced pERK1/2 was first apparent at 5-10 min and maximal at 30 min. Inhibition of PI3K completely blocked E 2 activation of pAkt at 10 and 30 min and blocked E 2 activation of ERK1/2 at 10 min, which revealed a PI3K-independent activation of ERK at 30 min. Double immunocytochemical labeling for pERK1/2 and pAkt demonstrated that E 2 induced both signaling pathways in the same neurons. These results indicate a unified signaling mechanism for rapid E 2 action that leads to the coordinated activation of both pERK1/2 and pAkt in the same population of neurons. Implications of these results for understanding estrogen mechanism of action in neurons and therapeutic development are considered.

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“…In many cases, it is clear that embryonic neurons behave differently than adult neurons in terms of pharmacology, electrophysiology, development, and regenerative and pathological characteristics. In such cases as calcium dynamics (5), glutamate sensitivity, and mitochondrial functions (6), the difference between the embryonic and adult neurons could be significant.…”

Section: Introductionmentioning

confidence: 99%

Isolation and culture of adult mouse vestibular nucleus neurons

Him¹,

Altuntaş²,

Öztürk³

et al. 2017

Turk J Med Sci

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Background/aim: Isolated cell cultures are widely used to study neuronal properties due to their advantages. Although embryonic animals are preferred for culturing, their morphological or electrophysiological properties may not reflect adult neurons, which may be important in neurodegenerative diseases. This paper aims to develop a method for preparing isolated cell cultures of medial vestibular nucleus (MVN) from adult mice and describe its morphological and electrophysiological properties.Materials and methods: Vestibular nucleus neurons were mechanically and enzymatically isolated and cultured using a defined medium with known growth factors. Cell survival was measured with propidium iodide, and electrophysiological properties were investigated with current-clamp recording.Results: Vestibular neurons grew neurites in cultures, gaining adult-like morphological properties, and stayed viable for 3 days in culture. Adding bovine calf serum, nerve growth factor, or insulin-like growth factor into the culture medium enhanced neuronal viability. Current-clamp recording of the cultured neurons revealed tonic and phasic-type neurons with similar input resistance, resting membrane potential, action potential amplitude, and duration. Conclusion:Vestibular neurons from adult mice can be cultured, and regenerate axons in a medium containing appropriate growth factors. Culturing adult vestibular neurons provides a new method to study age-related pathologies of the vestibular system.

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Prevention of age-related dysregulation of calcium dynamics by estrogen in neurons

Cited by 58 publications

References 47 publications

NbActiv4 medium improvement to Neurobasal/B27 increases neuron synapse densities and network spike rates on multielectrode arrays

NbActiv4 medium improvement to Neurobasal/B27 increases neuron synapse densities and network spike rates on multielectrode arrays

Estrogen Receptor Protein Interaction with Phosphatidylinositol 3-Kinase Leads to Activation of Phosphorylated Akt and Extracellular Signal-Regulated Kinase 1/2 in the Same Population of Cortical Neurons: A Unified Mechanism of Estrogen Action

Isolation and culture of adult mouse vestibular nucleus neurons

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