Effect of L‐theanine on sensorimotor gating in healthy human subjects. Issue 5 (25th December 2013)

• Record Type: Journal Article
• Authors: Ota, Miho; Wakabayashi, Chisato; Matsuo, Junko; Kinoshita, Yukiko; Hori, Hiroaki; Hattori, Kotaro; Sasayama, Daimei; Teraishi, Toshiya; Obu, Satoko; Ozawa, Hayato; Kunugi, Hiroshi
• Is Part Of: Psychiatry and clinical neurosciences. Volume 68:Issue 5(2014)
• Page Start: 337
• Page End: 343
• Publication Date: 2013-12-25
• Subjects: Psychiatry -- Periodicals; Neurology -- Periodicals; 616.89
• DOI: 10.1111/pcn.12134
• Languages: English
• ISSNs: 1323-1316

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="pcn12134-sec-0001" sec-type="section"> <title>Aim</title> <p> <sc>l</sc>‐Theanine (N‐ethyl‐<sc>l</sc>‐glutamine) is an amino acid uniquely found in green tea. Growing evidence has suggested the possible effects of <sc>l</sc>‐theanine on cognition. Previously, we found that <sc>l</sc>‐theanine attenuates MK‐801‐induced deficit in prepulse inhibition (PPI) in mice. In this study, we examined the effect of <sc>l</sc>‐theanine in increasing the PPI in healthy humans.</p> </sec> <sec id="pcn12134-sec-0002" sec-type="section"> <title>Methods</title> <p>The subjects were 14 healthy adults who underwent PPI testing as a measure of sensorimotor gating 90 min after an oral intake of <sc>l</sc>‐theanine (0, 200, 400, or 600 mg). PPI tests were done by examiners who were blind to the dose.</p> </sec> <sec id="pcn12134-sec-0003" sec-type="section"> <title>Results</title> <p>The administration of 200 mg of <sc>l</sc>‐theanine and that of 400 mg, but not 600 mg, significantly increased the % PPI compared to the baseline (0 mg). There was no significant relation between the dose of <sc>l</sc>‐theanine and the startle magnitude or the habituation of startle response. The plasma concentrations of <sc>l</sc>‐theanine correlated with the dose of <sc>l</sc>‐theanine.</p> </sec> <sec id="pcn12134-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The observed effect with 200–400 mg of <sc>l</sc>‐theanine on PPI suggested that <sc>l</sc>‐theanine at a particular dose range increases sensorimotor gating in humans.</p> </sec> </abstract>