Role of the alpha 1G T-type calcium channel in spontaneous absence seizures in mutant mice

Cited 109 time in webofscience Cited 116 time in scopus
  • Hit : 281
  • Download : 400
Alterations in thalamic T-type Ca2+ channels are thought to contribute to the pathogenesis of absence seizures. Here, we found that mice with a null mutation for the pore-forming alpha1A subunits of P/Q-type channels (alpha1A(-/-) mice) were prone to absence seizures characterized by typical spike-and-wave discharges (SWDs) and behavioral arrests. Isolated thalamocortical relay (TC) neurons from these mice showed increased T-type Ca2+ currents in vitro. To examine the role of increased T-currents in alpha1A(-/-) TC neurons, we cross-bred alpha1A(-/-) mice with mice harboring a null mutation for the gene encoding alpha1G, a major isotype of T-type Ca2+ channels in TC neurons. alpha1A(-/-)/alpha1G(-/-) mice showed a complete loss of T-type Ca2+ currents in TC neurons and displayed no SWDs. Interestingly, alpha1A(-/-)/alpha1G(+/-) mice had 75% of the T-type Ca2+ currents in TC neurons observed in alpha1A (+/+)/alpha1G (+/+) mice and showed SWD activity that was quantitatively similar to that in alpha1A (-/-)/alpha1G (+/+) mice. Similar results were obtained using double-mutant mice harboring the alpha1G mutation plus another mutation also used as a model for absence seizures, i.e., lethargic (beta4(1h/1h)), tottering (alpha1A(tg/tg)), or stargazer (gamma2(stg/stg)). The present results reveal that alpha1G T-type Ca2+ channels play a critical role in the genesis of spontaneous absence seizures resulting from hypofunctioning P/Q-type channels, but that the augmentation of thalamic T-type Ca2+ currents is not an essential step in the genesis of absence seizures.
Publisher
Soc Neuroscience
Issue Date
2004-06
Language
English
Article Type
Article
Keywords

SYNAPTIC-TRANSMISSION; CA2+ CHANNELS; SPIKE-WAVE; ACTION-POTENTIALS; THALAMIC NEURONS; RELAY NEURONS; RAT THALAMUS; IN-VITRO; N-TYPE; MOUSE

Citation

JOURNAL OF NEUROSCIENCE, v.24, no.22, pp.5249 - 5257

ISSN
0270-6474
DOI
10.1523/JNEUROSCI.5546-03.2004
URI
http://hdl.handle.net/10203/19378
Appears in Collection
BS-Journal Papers(저널논문)
Files in This Item
5249.full.pdf(461.73 kB)Download
This item is cited by other documents in WoS
⊙ Detail Information in WoSⓡ Click to see webofscience_button
⊙ Cited 109 items in WoS Click to see citing articles in records_button

qr_code

  • mendeley

    citeulike


rss_1.0 rss_2.0 atom_1.0