The selective A-type K+ current blocker Tx3-1 isolated from the Phoneutria nigriventer venom enhances memory of naïve and Aβ25-35-treated mice

Autor: Maribel Antonello Rubin, Juliano Ferreira, Guilherme M. Gomes, Gerusa Duarte Dalmolin, Marcus Vinicius Gomez, Marta N. Cordeiro
Rok vydání: 2013
Předmět:
Zdroj: Toxicon. 76:23-27
ISSN: 0041-0101
DOI: 10.1016/j.toxicon.2013.08.059
Popis: Potassium channels regulate many neuronal functions, including neuronal excitability and synaptic plasticity, contributing, by these means, to mnemonic processes. In particular, A-type K+ currents (IA) play a key role in hippocampal synaptic plasticity. Therefore, we evaluated the effect of the peptidic toxin Tx3-1, a selective blocker of IA currents, extracted from the venom of the spider Phoneutria nigriventer, on memory of mice. Administration of Tx3-1 (i.c.v., 300 pmol/site) enhanced both short- and long-term memory consolidation of mice tested in the novel object recognition task. In comparison, 4-aminopyridine (4-AP; i.c.v., 30–300 pmol/site), a non-selective K+ channel blocker did not alter long-term memory and caused toxic side effects such as circling, freezing and tonic–clonic seizures. Moreover, Tx3-1 (i.c.v., 10–100 pmol/site) restored memory of Aβ25-35-injected mice, and exhibited a higher potency to improve memory of Aβ25-35-injected mice when compared to control group. These results show the effect of the selective blocker of IA currents Tx3-1 in both short- and long-term memory retention and in memory impairment caused by Aβ25-35, reinforcing the role of IA in physiological and pathological memory processes.
Databáze: OpenAIRE
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