Electrophysiological Development of Central Neurons in the<i>Drosophila</i>Embryo

Baines, Richard A.; Bate, Michael

doi:10.1523/jneurosci.18-12-04673.1998

Cited by 170 publications

(265 citation statements)

References 40 publications

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“…The internal patch solution was as follows: 140 mM KCH 3 SO 3 , 2 mM MgCl 2 , 2 mM EGTA, 2 mM KCl, and 20 mM HEPES, pH 7.4. Central neurons were visualized and accessed for electrophysiology using an Olympus BX51W1 microscope and 60ϫ water-immersion lens combined with Nomarski optics, (Baines and Bate, 1998). RP2 and aCC motor neurons were initially identified by their size and location; after recording, their identity was confirmed (on the basis of morphology and axon trajectory) by labeling with 0.1% Alexa Fluor 488 hydrazide (Invitrogen), which was included in the internal patch solution.…”

Section: Methodsmentioning

confidence: 99%

DrosophilaGlial Glutamate Transporter Eaat1 Is Regulated by Fringe-Mediated Notch Signaling and Is Essential for Larval Locomotion

Stacey¹,

Muraro²,

Peco³

et al. 2010

J. Neurosci.

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In the mammalian CNS, glial cells expressing excitatory amino acid transporters (EAATs) tightly regulate extracellular glutamate levels to control neurotransmission and protect neurons from excitotoxic damage. Dysregulated EAAT expression is associated with several CNS pathologies in humans, yet mechanisms of EAAT regulation and the importance of glutamate transport for CNS development and function in vivo remain incompletely understood. Drosophila is an advanced genetic model with only a single high-affinity glutamate transporter termed Eaat1. We found that Eaat1 expression in CNS glia is regulated by the glycosyltransferase Fringe, which promotes neuron-to-glia signaling through the Delta-Notch ligand-receptor pair during embryogenesis. We made Eaat1 loss-of-function mutations and found that homozygous larvae could not perform the rhythmic peristaltic contractions required for crawling. We found no evidence for excitotoxic cell death or overt defects in the development of neurons and glia, and the crawling defect could be induced by postembryonic inactivation of Eaat1. Eaat1 fully rescued locomotor activity when expressed in only a limited subpopulation of glial cells situated near potential glutamatergic synapses within the CNS neuropil. Eaat1 mutants had deficits in the frequency, amplitude, and kinetics of synaptic currents in motor neurons whose rhythmic patterns of activity may be regulated by glutamatergic neurotransmission among premotor interneurons; similar results were seen with pharmacological manipulations of glutamate transport. Our findings indicate that Eaat1 expression is promoted by Fringe-mediated neuron-glial communication during development and suggest that Eaat1 plays an essential role in regulating CNS neural circuits that control locomotion in Drosophila.

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Section: Methodsmentioning

confidence: 99%

DrosophilaGlial Glutamate Transporter Eaat1 Is Regulated by Fringe-Mediated Notch Signaling and Is Essential for Larval Locomotion

Stacey¹,

Muraro²,

Peco³

et al. 2010

J. Neurosci.

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“…Wild-type was Canton-S. RN2-O and RN2-E GAL4 (homozygous viable, second and third chromosome, respectively) were used to selectively express UAS-driven transgenes in aCC and RP2 Baines, 2003). Expression of RN2 GAL4 begins in early stage 16 embryos, a stage that precedes the onset of synaptogenesis (Baines and Bate, 1998). Levels of cAMP were increased in specific neurons by expression of UAS-rut (a type I, Ca 2ϩ -calmodulin-dependent, adenylate cyclase) (Zars et al, 2000).…”

Section: Methodsmentioning

confidence: 99%

“…Larvae were dissected, and central neurons were accessed as described in Baines and Bate (1998). The larva was viewed using a water immersion lens (total magnification, 800ϫ) combined with Nomarski optics (BX51 WI microscope; Olympus Optical, Tokyo, Japan).…”

Section: Methodsmentioning

confidence: 99%

Synaptic Strengthening Mediated by Bone Morphogenetic Protein-Dependent Retrograde Signaling in theDrosophilaCNS

Baines¹

2004

J. Neurosci.

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Retrograde signaling is an essential component of synaptic development and physiology. Previous studies show that bone morphogenetic protein (BMP)-dependent retrograde signaling is required for the proper development of the neuromuscular junction (NMJ) in Drosophila. These studies, moreover, raised the significant possibility that the development of central motor circuitry might similarly be reliant on such signaling. To test this hypothesis, retrograde signaling between postsynaptic motoneurons and their presynaptic interneurons is examined. Postsynaptic expression of an adenylate cyclase encoded by rutabaga (rut), is sufficient to strengthen synaptic transmission at these identified central synapses. Results are presented to show that the underlying mechanism is dependent on BMP retrograde signaling. Thus, presynaptic expression of an activated TGF-␤ receptor, thickvien (tkv), or postsynaptic expression of a TGF-␤ ligand, glass-bottom boat ( gbb), is sufficient to phenocopy strengthening of synaptic transmission. In the absence of gbb, endogenous synaptic transmission is significantly weakened and, moreover, postsynaptic overexpression of rut is unable to potentiate synaptic function. Potentiation of presynaptic neurotransmitter release, mediated by increased postsynaptic expression of gbb, is dependent on normal cholinergic activity, indicative that either the secretion of this retrograde signal, or its transduction, is activity dependent. Thus, in addition to the development of the NMJ and expression of myoactive FMRFamide-like peptides in specific central neurons, the results of the present study indicate that this retrograde signaling cascade also integrates the development and function of central motor circuitry that controls movement in Drosophila larvae.

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“…Recordings were made from astrocytes in the 2 nd and 3 rd thoracic segments (T2,3) or from the 1 st abdominal segment (A1), where the space between the lateral and medial motor neuron clusters is larger, making the astrocyte cell bodies easier to identify than in the more posterior abdominal segments. Additionally, motor neuron physiology has been studied in these thoracic (Worrell and Levine, 2008) and upper abdominal (Baines and Bate, 1998) segments. All recordings were collected from one of the four astrocytes located on the dorsal surface of the neuropil of each hemisegment because the lateral and ventral astrocytes are too deep to access in wholemount tissue.…”

Section: Whole-cell Recordingsmentioning

confidence: 99%

Astrocytic glutamate transport regulates a Drosophila CNS synapse that lacks astrocyte ensheathment

MacNamee

Liu

Gerhard

et al. 2016

J of Comparative Neurology

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Anatomical, molecular, and physiological interactions between astrocytes and neuronal synapses regulate information processing in the brain. The fruit fly Drosophila melanogaster has become a valuable experimental system for genetic manipulation of the nervous system and has enormous potential for elucidating mechanisms that mediate neuron glia interactions. Here, we show the first electrophysiological recordings from Drosophila astrocytes and characterize their spatial and physiological relationship with particular synapses. Astrocyte intrinsic properties were found to be strongly analogous to those of vertebrate astrocytes, including a passive current-voltage relationship, low membrane resistance, high capacitance, and dye-coupling to local astrocytes. Responses to optogenetic stimulation of glutamatergic pre-motor neurons were correlated directly with anatomy using serial electron microscopy reconstructions of homologous identified neurons and surrounding astrocytic processes. Robust bidirectional communication was present: neuronal activation triggered astrocytic glutamate transport via Eaat1, and blocking Eaat1 extended glutamatergic interneuron-evoked inhibitory post-synaptic currents in motor neurons. The neuronal synapses were always located within a micron of an astrocytic process, but none were ensheathed by those processes. Thus, fly astrocytes can modulate fast synaptic transmission via neurotransmitter transport within these anatomical parameters. Graphical AbstractCorresponding Author: Sarah E. MacNamee, University of Arizona Dept. of Neuroscience, 1040 E 4 th St GS Rm 611, Tucson AZ 85721, (520) 621 6671, Smac3@email.arizona.edu. Role of AuthorsAll authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: SEM, LAO. Acquisition of data: SEM, KEL, SG, CTT, RDF, AC. Analysis and interpretation of data: SEM, KEL, CTT. Drafting of the manuscript: SEM. Critical revision of the manuscript for important intellectual content: LAO, LPT, AC. Statistical analysis: SEM. Obtained funding: LAO, LPT, AC. Administrative, technical, and material support: none. Study supervision: LAO, LPT. Conflict of Interest StatementThe authors have no conflict of interest to disclose. Data AccessibilityData generated in the lab and the subsequent analyses will be made available upon request to the Oland/Tolbert laboratory by qualified individuals as long as doing so would not compromise intellectual property interests or interfere with publication. Any shared data would include notations, standards, and the like that are necessary for interpretation of the data. HHMI Author Manuscript HHMI Author Manuscript HHMI Author ManuscriptThe authors show the first recordings from Drosophila astrocytes and find that their electrophysiological properties are strongly analogous to those of vertebrate astrocytes. Using correlative electron microscopy and physiology, they found no glial ensheathment of glutamatergic synap...

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Electrophysiological Development of Central Neurons in theDrosophilaEmbryo

Cited by 170 publications

References 40 publications

DrosophilaGlial Glutamate Transporter Eaat1 Is Regulated by Fringe-Mediated Notch Signaling and Is Essential for Larval Locomotion

DrosophilaGlial Glutamate Transporter Eaat1 Is Regulated by Fringe-Mediated Notch Signaling and Is Essential for Larval Locomotion

Synaptic Strengthening Mediated by Bone Morphogenetic Protein-Dependent Retrograde Signaling in theDrosophilaCNS

Astrocytic glutamate transport regulates a Drosophila CNS synapse that lacks astrocyte ensheathment

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