Broad-spectrum efficacy across cognitive domains by alpha7 nicotinic acetylcholine receptor agonism correlates with activation of ERK1/2 and CREB phosphorylation pathways. |
| Authors: |
Bitner, Robert S Bunnelle, William H Anderson, David J Briggs, Clark A Buccafusco, Jerry Curzon, Peter Decker, Michael W Frost, Jennifer M Gronlien, Jens Halvard Gubbins, Earl Li, Jinhe Malysz, John Markosyan, Stella Marsh, Kennan Meyer, Michael D Nikkel, Arthur L Radek, Richard J Robb, Holly M Timmermann, Daniel Sullivan, James P Gopalakrishnan, Murali
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| Citation: |
Bitner RS, etal., J Neurosci. 2007 Sep 26;27(39):10578-87. |
| RGD ID: |
12050111 |
| Pubmed: |
PMID:17898229 (View Abstract at PubMed) |
| PMCID: |
PMC6673141 (View Article at PubMed Central) |
| DOI: |
DOI:10.1523/JNEUROSCI.2444-07.2007 (Journal Full-text) |
The alpha7 nicotinic acetylcholine receptor (nAChR) plays an important role in cognitive processes and may represent a drug target for treating cognitive deficits in neurodegenerative and psychiatric disorders. In the present study, we used a novel alpha7 nAChR-selective agonist, 2-methyl-5-(6-phenyl-pyridazin-3-yl)-octahydro-pyrrolo[3,4-c]pyrrole (A-582941) to interrogate cognitive efficacy, as well as examine potential cellular mechanisms of cognition. Exhibiting high affinity to native rat (Ki = 10.8 nM) and human (Ki = 16.7 nM) alpha7 nAChRs, A-582941 enhanced cognitive performance in behavioral assays including the monkey delayed matching-to-sample, rat social recognition, and mouse inhibitory avoidance models that capture domains of working memory, short-term recognition memory, and long-term memory consolidation, respectively. In addition, A-582941 normalized sensory gating deficits induced by the alpha7 nAChR antagonist methyllycaconitine in rats, and in DBA/2 mice that exhibit a natural sensory gating deficit. Examination of signaling pathways known to be involved in cognitive function revealed that alpha7 nAChR agonism increased extracellular-signal regulated kinase 1/2 (ERK1/2) phosphorylation in PC12 cells. Furthermore, increases in ERK1/2 and cAMP response element-binding protein (CREB) phosphorylation were observed in mouse cingulate cortex and/or hippocampus after acute A-582941 administration producing plasma concentrations in the range of alpha7 binding affinities and behavioral efficacious doses. The MEK inhibitor SL327 completely blocked alpha7 agonist-evoked ERK1/2 phosphorylation. Our results demonstrate that alpha7 nAChR agonism can lead to broad-spectrum efficacy in animal models at doses that enhance ERK1/2 and CREB phosphorylation/activation and may represent a mechanism that offers potential to improve cognitive deficits associated with neurodegenerative and psychiatric diseases, such as Alzheimer's disease and schizophrenia.
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| Genes (Rattus norvegicus) |
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| Chrna7 (cholinergic receptor nicotinic alpha 7 subunit) |
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