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Calcium Imaging of Neuronal Activity in Drosophila Can Identify Anticonvulsive Compounds.
- Source :
-
PloS one [PLoS One] 2016 Feb 10; Vol. 11 (2), pp. e0148461. Date of Electronic Publication: 2016 Feb 10 (Print Publication: 2016). - Publication Year :
- 2016
-
Abstract
- Although there are now a number of antiepileptic drugs (AEDs) available, approximately one-third of epilepsy patients respond poorly to drug intervention. The reasons for this are complex, but are probably reflective of the increasing number of identified mutations that predispose individuals to this disease. Thus, there is a clear requirement for the development of novel treatments to address this unmet clinical need. The existence of gene mutations that mimic a seizure-like behaviour in the fruit fly, Drosophila melanogaster, offers the possibility to exploit the powerful genetics of this insect to identify novel cellular targets to facilitate design of more effective AEDs. In this study we use neuronal expression of GCaMP, a potent calcium reporter, to image neuronal activity using a non-invasive and rapid method. Expression in motoneurons in the isolated CNS of third instar larvae shows waves of calcium-activity that pass between segments of the ventral nerve cord. Time between calcium peaks, in the same neurons, between adjacent segments usually show a temporal separation of greater than 200 ms. Exposure to proconvulsants (picrotoxin or 4-aminopyridine) reduces separation to below 200 ms showing increased synchrony of activity across adjacent segments. Increased synchrony, characteristic of epilepsy, is similarly observed in genetic seizure mutants: bangsenseless1 (bss1) and paralyticK1270T (paraK1270T). Exposure of bss1 to clinically-used antiepileptic drugs (phenytoin or gabapentin) significantly reduces synchrony. In this study we use the measure of synchronicity to evaluate the effectiveness of known and novel anticonvulsive compounds (antipain, isethionate, etopiside rapamycin and dipyramidole) to reduce seizure-like CNS activity. We further show that such compounds also reduce the Drosophila voltage-gated persistent Na+ current (INaP) in an identified motoneuron (aCC). Our combined assays provide a rapid and reliable method to screen unknown compounds for potential to function as anticonvulsants.
- Subjects :
- 4-Aminopyridine pharmacology
Adult
Amines pharmacology
Animals
Anticonvulsants chemical synthesis
Antipain pharmacology
Calmodulin genetics
Calmodulin metabolism
Central Nervous System cytology
Central Nervous System drug effects
Central Nervous System metabolism
Convulsants pharmacology
Cyclohexanecarboxylic Acids pharmacology
Dipyridamole pharmacology
Drosophila Proteins genetics
Drosophila Proteins metabolism
Drosophila melanogaster cytology
Drosophila melanogaster metabolism
Female
Gabapentin
Gene Expression
Genes, Reporter
Green Fluorescent Proteins genetics
Green Fluorescent Proteins metabolism
Humans
Larva cytology
Larva drug effects
Larva metabolism
Male
Molecular Imaging methods
Motor Neurons cytology
Motor Neurons metabolism
Phenytoin pharmacology
Picrotoxin pharmacology
Primary Cell Culture
Sodium Channels genetics
Sodium Channels metabolism
gamma-Aminobutyric Acid pharmacology
Anticonvulsants pharmacology
Calcium metabolism
Drosophila melanogaster drug effects
High-Throughput Screening Assays
Motor Neurons drug effects
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 11
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 26863447
- Full Text :
- https://doi.org/10.1371/journal.pone.0148461