| First Author | Westphalen RI | Year | 2007 |
| Journal | Br J Pharmacol | Volume | 152 |
| Issue | 6 | Pages | 939-45 |
| PubMed ID | 17828284 | Mgi Jnum | J:148661 |
| Mgi Id | MGI:3846035 | Doi | 10.1038/sj.bjp.0707450 |
| Citation | Westphalen RI, et al. (2007) Reduced inhibition of cortical glutamate and GABA release by halothane in mice lacking the K+ channel, TREK-1. Br J Pharmacol 152(6):939-45 |
| abstractText | BACKGROUND AND PURPOSE: Deletion of TREK-1, a two-pore domain K(+) channel (K(2P)) activated by volatile anaesthetics, reduces volatile anaesthetic potency in mice, consistent with a role for TREK-1 as an anaesthetic target. We used TREK-1 knockout mice to examine the presynaptic function of TREK-1 in transmitter release and its role in the selective inhibition of glutamate vs GABA release by volatile anaesthetics. EXPERIMENTAL APPROACH: The effects of halothane on 4-aminopyridine-evoked and basal [(3)H]glutamate and [(14)C]GABA release from cerebrocortical nerve terminals isolated from TREK-1 knockout (KO) and littermate wild-type (WT) mice were compared. TREK-1 was quantified by immunoblotting of nerve terminal preparations. KEY RESULTS: Deletion of TREK-1 significantly reduced the potency of halothane inhibition of 4-aminopyridine-evoked release of both glutamate and GABA without affecting control evoked release or the selective inhibition of glutamate vs GABA release. TREK-1 deletion also reduced halothane inhibition of basal glutamate release, but did not affect basal GABA release. CONCLUSIONS AND IMPLICATIONS: The reduced sensitivity of glutamate and GABA release to inhibition by halothane in TREK-1 KO nerve terminals correlates with the reduced anaesthetic potency of halothane in TREK-1 KO mice observed in vivo. A presynaptic role for TREK-1 was supported by the enrichment of TREK-1 in isolated nerve terminals determined by immunoblotting. This study represents the first evidence for a link between an anaesthetic-sensitive 2-pore domain K(+) channel and presynaptic function, and provides further support for presynaptic mechanisms in determining volatile anaesthetic action. |
