AMPA Receptor antagonist NBQX attenuates later‐life epileptic seizures and autistic‐like social deficits following neonatal seizures. Issue 11 (1st October 2013)

• Record Type: Journal Article
• Authors: Lippman‐Bell, Jocelyn J.; Rakhade, Sanjay N.; Klein, Peter M.; Obeid, Makram; Jackson, Michele C.; Joseph, Annelise; Jensen, Frances E.
• Is Part Of: Epilepsia. Volume 54:Issue 11(2013:Nov.)
• Page Start: 1922
• Page End: 1932
• Publication Date: 2013-10-01
• Subjects: Epilepsy -- Periodicals; 616.853
• DOI: 10.1111/epi.12378
• Languages: English
• ISSNs: 0013-9580

Abstract

<abstract abstract-type="main" id="epi12378-abs-0001"> <title>Summary</title> <sec id="epi12378-sec-0001" sec-type="section"> <title>Purpose</title> <p>To determine whether AMPA receptor (AMPAR) antagonist NBQX can prevent early mammalian target of rapamycin (mTOR) pathway activation and long‐term sequelae following neonatal seizures in rats, including later‐life spontaneous recurrent seizures, CA3 mossy fiber sprouting, and autistic‐like social deficits.</p> </sec> <sec id="epi12378-sec-0002" sec-type="section"> <title>Methods</title> <p>Long‐Evans rats experienced hypoxia‐induced neonatal seizures (HS) at postnatal day (P)10. NBQX (20 mg/kg) was administered immediately following HS (every 12 h × 4 doses). Twelve hours post‐HS, we assessed mTOR activation marker phosphorylated p70‐S6 kinase (p‐p70S6K) in hippocampus and cortex of vehicle (HS + V) or NBQX‐treated post‐HS rats (HS + N) versus littermate controls (C + V). Spontaneous seizure activity was compared between groups by epidural cortical electroencephalography (EEG) at P70–100. Aberrant mossy fiber sprouting was measured using Timm staining. Finally, we assessed behavior between P30 and P38.</p> </sec> <sec id="epi12378-sec-0003" sec-type="section"> <title>Key Findings</title> <p>Postseizure NBQX treatment significantly attenuated seizure‐induced increases in p‐p70S6K in the hippocampus (p < 0.01) and cortex (p < 0.001). Although spontaneous recurrent seizures increased in adulthood in HS + V rats compared to controls (3.22 ± 1 seizures/h; p = 0.03), NBQX significantly attenuated later‐life seizures (0.14 ± 0.1 seizures/h; p = 0.046). HS + N rats showed less aberrant mossy fiber sprouting (115 ± 8.0%) than vehicle‐treated post‐HS rats (174 ± 10%, p = 0.004), compared to controls (normalized to 100%). Finally, NBQX treatment prevented alterations in later‐life social behavior; post‐HS rats showed significantly decreased preference for a novel over a familiar rat (71.0 ± 12 s) compared to controls (99.0 ± 15.6 s; p < 0.01), whereas HS + N rats showed social novelty preference similar to controls (114.3 ± 14.1 s).</p> </sec> <sec id="epi12378-sec-0004" sec-type="section"> <title>Significance</title> <p>Brief NBQX administration during the 48 h postseizure in P10 Long‐Evans rats suppresses transient mTOR pathway activation and attenuates spontaneous recurrent seizures, social preference deficits, and mossy fiber sprouting observed in vehicle‐treated adult rats after early life seizures. These results suggest that acute AMPAR antagonist treatment during the latent period immediately following neonatal HS can modify seizure‐induced activation of mTOR, reduce the frequency of later‐life seizures, and protect against CA3 mossy fiber sprouting and autistic‐like social deficits.</p> </sec> </abstract>