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Updated: Jun 10, 2025
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Multi-unit Recording Methods to Characterize Neural Activity in the Locust Schistocerca Americana Olfactory Circuits
Published on: January 25, 2013
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Palytoxin evokes reversible spreading depolarization in the locust CNS
Yuyang Wang1, Rachel A Van Dusen1, Catherine McGuire2
1Department of Biology, Queen's University, Kingston, Ontario, Canada.
Journal of Neurophysiology
|October 16, 2024
Summary
Palytoxin (PLTX) can initiate spreading depolarization (SD) in locusts by converting the sodium-potassium ATPase (NKA) into an ion channel. This rapid and reversible SD mechanism offers insights into CNS dysfunction and potential therapeutic targets.
Area of Science:
- Neuroscience
- Ion Channel Physiology
- Insect Neurobiology
Background:
- Spreading depolarization (SD) is a key event in central nervous system (CNS) dysfunction, but the initiating ion channel remains unidentified.
- The sodium-potassium ATPase (NKA) has been hypothesized to act as an ion channel, potentially mediating SD.
- Palytoxin (PLTX) is known to convert NKA into an ion channel.
Purpose of the Study:
- To investigate the effectiveness of palytoxin (PLTX) in initiating spreading depolarization (SD) in the locust central nervous system (CNS).
- To explore the properties and mechanism of PLTX-induced SD.
- To evaluate the role of NKA conversion in SD initiation.
Main Methods:
- Direct injection of PLTX into the neuropil of *Locusta migratoria*.
- Comparison of PLTX-induced SD with ouabain (OUA) and azide-induced SD.
- Electrophysiological recording to assess SD onset, features, and recovery.
Main Results:
- Direct PLTX injection triggered SD in 57% of locust preparations, with a more rapid onset than OUA or azide.
- PLTX-induced SD was recoverable and led to more frequent repetitive events compared to OUA.
- Prior PLTX treatment interfered with subsequent SD initiation and recovery, and higher doses inhibited azide-induced SD.
Conclusions:
- Palytoxin (PLTX) can induce rapid, reversible, and repetitive SD-like events in the locust CNS, supporting the NKA channel hypothesis.
- PLTX's ability to modulate other SD triggers suggests complex interactions within the CNS.
- The findings provide strong evidence for NKA pump conversion into an ion channel as a plausible mechanism for SD activation in the locust CNS.
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