transheterozygotes show an abnormal and fully penetrant paralysis phenotype upon exposure to 14[o]C or 10[o]C temperatures, which is associated with a significant increase in recovery time from paralysis upon shift to room temperature, as compared to jusiso7.8
heterozygous and wild-type controls. jusiso7.8
homozygotes also show an abnormal and nearly fully penetrant paralysis phenotype upon exposure to 10[o]C, but not 14[o]C, temperatures, which is also associated with a significant increase in recovery time from paralysis upon shift to room temperature, as compared to jusiso7.8
heterozygous and wild-type controls.
mutants suffer paralysis upon exposure to 10s of strobe light (10-50Hz), whose penetrance is variable dependent on the genetic background, and suffer seizures upon exposure to refrigerated food.
as well as jusiso7.8
flies are bang sensitive with increasing recovery time.
High frequency electrical stimulation of jusiso7.8
mutant flies induces primary seizure occuring immediately after the stimulus followed by a secondary 'recovery' seizure around 30 sec later - this is significantly shorter than in the jusf04904
mutants where the average interval between seizures is about 70 sec, the seizure stimulus threshold however is comparable between the mutants.
flies are bang sensitive and have a low seizure threshold in response to high frequency stimulation (similar at room temperature or after brief heat shock).
mutants are bang sensitive, and do not exhibit synaptic transmission defects upon stimulation of the GF circuit.
mutant testicular niches display decreased hub cell numbers in L2, L3 and adults (but not L1), but no evidence of hub cell death or transdifferentiation; these mutants also show significantly decreased germline stem cell numbers in L2, L3 and adults (but not L1), and decreased cyst stem cell numbers in adults (but not in L3 stage).
mutant male germline stem cells display increased mitotic activity (stage unspecified), a significant increase in misoriented centrosomes (adult), a significant decrease in disintegrating fusomes (stage unspecified), and a decrease in the number of germline stem cells with multiple ring canals (stage unspecified) as compared to wild type.
/+ mutant testicular niches display decreased numbers of hub cells, germline stem cells and cyst stem cells as compared with controls. (stage unspecified)
There is a drastic increase in DLM firing frequency in sdaiso7.8
mutants following electroconvulsive seizures (ECS). The temporal characteristics of the ECS-induced wing buzzing shows a gross discrepancy with the DLM firing pattern. Unlike in wild-type, the wing beat frequency in these mutants does not appear to be temporally coupled with the DLM firing episode. Instead, an abrupt termination of wing beats occurs during DLM firing, followed by quiescence prior to a second bout of wing beats when DLM firing is terminated.
Injection of 25mM valproate saline solution greatly increases the seizure threshold of sdaiso7.8
mutants (i.e. suppresses the seizure phenotype), by approximately 7 times (to above wild-type levels without 25mM valproate injection).
larvae exhibit prolonged seizures after electroshock.
adult flies exhibit a significantly longer mean recovery time after electroshock compared to wild-type.
Voltage-clamp recordings of spontaneous rhythmic currents in sdaiso7.8
mutant third instar larvae motoneurons show a significant increase in both amplitude and duration. Mini synaptic currents do not show a significant difference in amplitude. The frequency of spontaneous rhythmic currents in sdaiso7.8
mutants is significantly reduced, compared to wild-type.
mutant larvae exhibit significantly slower crawling than their wild-type counterparts, reflecting the reduced frequency of motor excitation.
Current-clamp recordings show that the depolarizations observed in sdaiso7.8
mutant aCC/RP2 motoneurons are slightly larger in amplitude and considerably longer in duration than in wild-type motoneurons and result in increased action potential firing.
aCC/RP2 motoneurons in sdaiso7.8
mutants exhibit altered membrane conductances, such that they have an intrinsically reduced membrane excitability.
mutant larvae with phenytoin ameliorates seizure-like behavior in these larvae. Similar marked reductions are seen in synaptic current duration and spontaneous rhythmic current amplitude, whereas no significant changes are observed in frequency.
Feeding gravid sdaiso7.8
females with phenytoin results in their offspring exhibiting a complete rescue of mean recovery time from electroshock, relative to controls. The phenytoin is sufficient to suppress synaptic excitation of aCC/RP2 motoneurons.
Mean recovery time from bang sensitive paralysis following a mechanical shock is approximately 38 seconds in mutant flies.
Mutant flies have a reduced seizure threshold (the minimum voltage required to induce seizure activity in the dorsal longitudinal muscles after a high-frequency stimulus) compared to controls.
Homozygous flies show 100% bang sensitivity.
Mutants are bang-sensitive, with a recovery period of 37 +/- 5 seconds and a refractory period of 430 +/- 25 seconds.
Mutant flies show a reduced seizure threshold (of 8.3 +/- 0.4 V) compared to wild type in response to high-frequency electrical stimulation.
/+ mutants show a lower seizure threshold in the giant fibre pathway than wild type (30.6 +/- 4.5V in heterozygous females compared to 44.5 +/- 4.4V in wild-type females).
Bang-sensitive mutant. Flies usually show abnormal spontaneous activity ("seizures") in the dorsal longitudinal muscle (DLM) lasting approximately 0.5-3 seconds after the delivery of an electrical buzz (50-400 msec) to the brain. Stimulation of the giant fibre (GF) usually fails to evoke DLM potentials following the buzz. This failure lasts for 88 +/- 37 seconds. There is a close correlation between the seizure and failure phenotypes; if a seizure occurs, a failure also occurs in greater than 95% of cases, while failures without seizures occurred in approximately 10% of cases. GF evoked responses by the DLM are abnormal during recovery from the buzz. After recovery, there is a refactory period during which a buzz is less effective at inducing seizures and failures.