| First Author | Neitz A | Year | 2014 |
| Journal | Cereb Cortex | Volume | 24 |
| Issue | 7 | Pages | 1923-36 |
| PubMed ID | 23448871 | Mgi Jnum | J:222464 |
| Mgi Id | MGI:5644638 | Doi | 10.1093/cercor/bht048 |
| Citation | Neitz A, et al. (2014) Postsynaptic NO/cGMP increases NMDA receptor currents via hyperpolarization-activated cyclic nucleotide-gated channels in the hippocampus. Cereb Cortex 24(7):1923-36 |
| abstractText | The nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling cascade participates in the modulation of synaptic transmission. The effects of NO are mediated by the NO-sensitive cGMP-forming guanylyl cyclases (NO-GCs), which exist in 2 isoforms with indistinguishable regulatory properties. The lack of long-term potentiation (LTP) in knock-out (KO) mice deficient in either one of the NO-GC isoforms indicates the contribution of both NO-GCs to LTP. Recently, we showed that the NO-GC1 isoform is located presynaptically in glutamatergic neurons and increases the glutamate release via hyperpolarization-activated cyclic nucleotide (HCN)-gated channels in the hippocampus. Electrophysiological analysis of hippocampal CA1 neurons in whole-cell recordings revealed a reduction of HCN currents and a hyperpolarizing shift of the activation curve in the NO-GC2 KOs associated with reduced resting membrane potentials. These features were mimicked in wild-type (WT) neurons with an NO-GC inhibitor. Analysis of glutamate receptors revealed a cGMP-dependent reduction of NMDA receptor currents in the NO-GC2 KO mice, which was mimicked in WT by HCN channel inhibition. Lowering extracellular Mg(2+) increased NMDA receptor currents in the NO-GC2 KO and allowed the induction of LTP that was absent at physiological Mg(2+). In sum, our data indicate that postsynaptic cGMP increases the N-methyl-D-aspartate (NMDA) receptor current by gating HCN channels and thereby is required for LTP. |
