Harun BAŞOĞLU, Hilal ÖZTÜRK, Hatice KESER, Selcen AYDİN-ABİDİN, İsmail ABİDİN

L-Theanin beyin kesitlerinde epileptiform aktiviteyi azaltır

L-Theanin Beyin Kesitlerinde Epileptiform Aktiviteyi Azaltır ÖZ Amaç: L-theanine, kan beyin bariyerini geçebilen çay bitkisinin ana amino asitlerinden biridir. Merkezi sinir sisteminde, L-theanine'in bir dizi nörotransmiter sistemi üzerinde belirli etkileri vardır. Bu çalışmada, L-theanine'nin akut uygulamasının beyin kesitlerinde herhangi bir nöbet benzeri veya inhibe edici aktiviteye yol açıp açmayacağını test ettik. Gereç ve Yöntemler: L-theanine'in epileptiform aktivite üzerindeki etkileri iki farklı beyin bölgesinde araştırıldı. Yatay hipokampal-entorinal korteks dilimleri, 32-36 günlük C57BL/6 farelerinden elde edildi. Hücre dışı alan potansiyelleri medial entorinal korteks (EC) ve hipokampusun CA3 bölgesinden kaydedildi. Epileptiform aktivite, beyin dilimlerine 4 Aminopiridin (4AP, 100 µM) uygulanarak indüklendi ve 50 µM L-theanine uygulandı. Kayıtlardan iktal benzeri olayların süresi ve sıklığı ile interiktal benzeri aktivitelerin frekansı ve genliği hesaplandı. Bulgular: L-theanine tek başına herhangi bir senkronize aktivite başlatmadı. 4AP ile indüklenen epileptiform aktivite sonrası L-theanine'in banyo uygulaması iktal deşarjların süresini ve sıklığını önemli ölçüde değiştirmese de, L-theanine interiktal deşarjları azalttı. EC'de interiktal deşarjların sıklıkları anlamlı ölçüde azaldı. CA3'te, interiktal aktivitelerin amplitüdleri anlamlı ölçüde azaldı. Sonuç: Bulgularımız, L-theanine'in herhangi bir nöbet benzeri olay uyarmadığını, bunun yerine devam eden epileptiform aktivite üzerinde baskılayıcı bir etkiye sahip olduğunu göstermektedir. Anahtar Sözcükler: Theanine, 4 Aminopiridin, Beyin Kesiti, Epileptiform aktivite, CA3, Entorinal Korteks

Anahtar Kelimeler:

Theanine, 4 Aminopiridin, Beyin Kesiti, Epileptiform aktivite, CA3, Entorinal Korteks

L-Theanine Reduces Epileptiform Activity In Brain Slices

L-Theanine Reduces Epileptiform Activity In Brain Slices ABSTRACT Objective: L-theanine is one of the main amino acid of tea plant which can cross the blood brain barrier. In the central nervous system, L-theanine has certain effects on a number of neurotransmitter systems. In this study we tested whether acute application of L-theanine could induce any seizure like or inhibitory activity in the brain slice. Materials and Methods: Effects of L-theanine on epileptiform activity were investigated in two different brain regions. Horizontal hippocampal-entorhinal cortex slices were obtained from 30-35 days old C57BL/6 mice. Extracellular field potentials were recorded from medial entorhinal cortex (EC) and CA3 region of hippocampus. Epileptiform activity was induced by application of 4 Aminopyridine (4AP, 100 µM) in the brain slices and 50 µM L-theanine was applied. From the recordings, the duration and frequencies of ictal like events as well as frequency and amplitude of inter-ictal like activities were calculated. Results: L-theanine alone did not initiate any synchronized activity. Although, bath application of L-theanine after 4AP induces epileptiform acitivities, did not significantly alter the duration and frequency of ictal discharges, L-theanine attenuated the interictal discharges. In EC the frequencies of interictal discharges were significantly decreased. In CA3, the amplitudes of interictal activities were significantly reduced. Conclusion: The present findings suggest that L-theanine do not induce any seizure like event but rather had a suppressive effect on ongoing epileptiform activity. Key Words: Theanine, 4 Aminopyridine, Brain Slice, Epileptiform activity, CA3, Entorhinal cortex

Keywords:

Theanine, 4 Aminopyridine, Brain Slice, Epileptiform activity, CA3, Entorhinal cortex,

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