High Concentrations Of Gamma-aminobutyric Acid Research Articles

Production of GABA in milk fermented by Bifidobacterium adolescentis strains selected on the bases of their technological and gastrointestinal performance

There is an increasing interest in producing foods enriched in gamma-aminobutyric acid (GABA), due to their purported health promoting attributes. GABA is the main inhibitor neurotransmitter of the central nervous system, and several microbial species are capable to produce it through decarboxylation of glutamate. Among them, several lactic acid bacteria species have been previously investigated as an appealing alternative to produce GABA enriched foods via microbial fermentation. In this work we report for the first time an investigation into the possibility of utilizing high GABA-producing Bifidobacterium adolescentis strains as a mean to produce fermented probiotic milks naturally enriched in GABA. To this end, in silico and in vitro analyses were conducted in a collection of GABA-producing B. adolescentis strains, with the main goal to scrutinize their metabolic and safety traits, including antibiotic resistance patterns, as well as their technological robustness and performance to survive a simulated gastrointestinal passage. One of the strains, IPLA60004, exhibited better survival to lyophilization and cold storage (for up to 4 weeks at 4 °C), as well as survival to gastrointestinal passage, as compared to the other strains under investigation. Besides, the elaboration of milk drinks fermented with this strain, yielded products with the highest GABA concentration and viable bifidobacterial cell counts, achieving conversion rates of the precursor, monosodium glutamate (GMS), up to 70 %. To our knowledge, this is the first report on the elaboration of GABA enriched milks through fermentation with B. adolescentis.

Changes in Spirulina's Physical and Chemical Properties during Submerged and Solid-State Lacto-Fermentation.

The aim of this study was to select a lactic acid bacteria (LAB) strain for bio-conversion of Spirulina, a cyanobacteria ("blue-green algae"), into an ingredient with a high concentration of gamma-aminobutyric acid (GABA) for human and animal nutrition. For this purpose, ten different LAB strains and two different fermentation conditions (SMF (submerged) and SSF (solid state fermentation)) were tested. In addition, the concentrations of fatty acids (FA) and biogenic amines (BA) in Spirulina samples were evaluated. It was established that Spirulina is a suitable substrate for fermentation, and the lowest pH value (4.10) was obtained in the 48 h SSF with Levilactobacillus brevis. The main FA in Spirulina were methyl palmitate, methyl linoleate and gamma-linolenic acid methyl ester. Fermentation conditions were a key factor toward glutamic acid concentration in Spirulina, and the highest concentration of GABA (2395.9 mg/kg) was found in 48 h SSF with Lacticaseibacillus paracasei samples. However, a significant correlation was found between BA and GABA concentrations, and the main BA in fermented Spirulina samples were putrescine and spermidine. Finally, the samples in which the highest GABA concentrations were found also displayed the highest content of BA. For this reason, not only the concentration of functional compounds in the end-product must be controlled, but also non-desirable substances, because both of these compounds are produced through similar metabolic pathways of the decarboxylation of amino acids.

Producing and analyzing gamma-aminobutyric acid containing probiotic black grape juice using Lactobacillus plantarum plantarum IBRC(10817) and Lactobacillus brevis IBRC(10818)

In this study, Lactobacillus plantarum plantarum IBRC (10817) and Lactobacillus brevis IBRC(10818) were used to determine whether it was possible to produce probiotic black grape beveraes that contained gamma-aminobutyric acid . In different containers, grape juice was individually inoculated with 3 ×107 (CFU/ml) of each microorganism for this purpose. Over the duration of 28 days, the amount of gamma-aminobutyric acid produced, changes in the viability of the microorganisms, and some physicochemical and sensory properties were assessed. According to the results, gamma-aminobutyric acid production increased up until day 21 of the fermentation process before beginning to decline on day 28. It was completely obvious that this beverage was probiotic until the end of day 21 . The number of probiotic microorganisms in both samples of various bacteria increased after 72 h and then decreased until the end of the period, showing no detectable difference between the two bacterial species in terms of viability. On day 21, the fermented beverage that had been inoculated with Lactobacillus plantarum plantarum IBRC(10817) had a high concentration of gamma-aminobutyric acid (117.33 mg/l). At the end of the storage time, there was no noticeable variation in their overall acceptance, and the acceptance score was 4-5. According to this study, Lactobacillus plantarum plantarum IBRC(10817) was more effective in producing probiotic beverages from black grape juice that also had a high level of sensory acceptability and gamma-aminobutyric acid.

Optimization of the hongqu starter preparation process for the manufacturing of red mold rice with high gamma-aminobutyric acid production by solid-state fermentation.

Red mold rice (RMR) generally contains gamma-aminobutyric acid (GABA), which has several physiological functions. Monascus purpureus M162, with a high GABA production of 15.10 mg/g was generated by atmospheric and room temperature plasma mutation. Furthermore, we conducted a response surface methodology to produce a premium hongqu starter. The results revealed that under optimal conditions, that is, a substrate containing brown rice and bran in a brown rice: bran ratio of 9:1 (wt/wt), an inoculation size of 21.50 mL/100 g, a mixing frequency of one time/9 h, and a cultivation time of 7.20 days, the number of active spores, α-amylase activity, and saccharification power activity was 4.15 × 107 spores/g, 155 U/g, and 3260 U/g in the high-quality starter, respectively. These values were 224.32-fold, 139.64%, and 141.74% higher than those obtained with M. purpureus M162 inoculated into steamed indica rice, respectively, and 153.70-fold, 267.24%, and 151.63% higher than those obtained with the parent strain M. purpureus M1, respectively. The premium hongqu starter of M. purpureus M162 was inoculated into steamed indica rice to produce RMR with 15.93 mg/g of GABA. In conclusion, we proposed a novel strategy for functional RMR production with high GABA concentrations by solid-state fermentation with Monascus spp.

Gamma-aminobutyric acid (GABA) production in fermented milk by lactic acid bacteria isolated from spontaneous raw milk fermentation

Lactic acid bacteria (LAB) may release bioactive compounds in fermented milk such as γ-aminobutyric acid (GABA) that have positive effects on human health. In the present work, from spontaneous raw milk fermentations 14 LAB strains belonging to 6 species were isolated. Their technological and nutritional characterisation led to the selection of two strains of Lactococcus lactis with a high GABA-producing capability in milk, enhanced by the addition of 5 mmol of monosodium glutamate (up to 249.31 mg L−1) and by co-culture with Lacticaseibacillus rhamnonus or Lacticaseibacillus paracasei. Fermented milks obtained by the two mixed starters (Lc. lactis and L. rhamnonus or L. paracasei) were characterised by a final GABA content of 185.81 ± 24.0 and 319.72 ± 27.15 mg L−1, respectively. GABA content increased during the storage, reaching 395.84 ± 12.55 and 377.49 ± 46.62 mg L−1. In conclusion, the selected starters represent a natural tool for the production of fermented milk containing high GABA concentrations.

The growth and potential of gamma-aminobutyric acid (GABA) by lactic acid bacteria isolated from fish fermented food from Maluku, Indonesia

GABA is a non-protein amino acid that is widely distributed in plants, animals and microorganisms. GABA can increase plasma concentration, growth hormone and protein synthesis in the brain. Several studies have shown that LAB can reduce pathological conditions due to oxidative stress, which indicates that LAB has antioxidant activity. One of the metabolites produced by LAB is GABA. The purpose of this study was to determine the growth of LAB isolates, the ability of GABA production and to know the character of INS-A2 and INS A4 isolates as a result of isolation from fish fermented. Bacterial growth was carried out for 60 hours 37°C. The growth of LAB isolates INS-A2 and INS-A4 were treated with the addition of MSG and non-MSG 2% in MRSB. GABA production can be identified qualitatively by the Thin Layer Chromatography (TLC) method using the aluminum TLC plate (Silica gel F254, Merck, Mumbai India). The LAB inoculum which was treated on MRSB media was centrifuged at a speed of 6000 rpm for 20 minutes at 4°C, the supernatant was deposited or dropped on the TLC plate. TLC was carried out using an eluent consisting of a mixture of n-butanol: acetic acid: distilled water in a ratio of 5:3:2. The Rf value of GABA compound produced by LAB INS-A2 and INS A4 isolates was 0.62, GABA standard (Pregabalin) 0.62, Rf MSG = 0.23. Based on the results of the study it can be concluded that the highest growth of INS A2 MSG isolate at 24 hours, INS-A2 non MSG highest at 30 hours. The highest growth of INS A4 MSG isolate at 30 hours and INS-A4 non MSG highest at 36 hours. The highest GABA concentration was owned by INS-A2 MSG isolate of 20,0 mg/ml. INS-A2 non MSG isolate 17,5 mg/ml, INS-A4 MSG 18,8 mg/ml and INS-A4 non-MSG 15,9 mg/ml. LAB characterization of INS-A2 and INS-A4 isolates obtained negative catalase, negative motility, fermentation type test (homofermentative) and gram-positive staining in accordance with the characteristics of BAL in general.

Higher GABA concentration in the medial prefrontal cortex of Type 2 diabetes patients is associated with episodic memory dysfunction.

Type 2 diabetes (T2D) is associated with an accelerated episodic memory decline, but the underlying pathophysiological mechanisms are not well understood. Hallmarks of T2D comprise impairment of insulin secretion and insulin sensitivity. Insulin signaling modulates cerebral neurotransmitter activity, including the excitatory glutamate and inhibitory gamma-aminobutyric acid (GABA) systems. Here we tested the hypothesis that the glutamate and GABA systems are altered in T2D patients and this relates to memory decline and insulin resistance. Using 1 H-magnetic resonance spectroscopy (MRS), we examined glutamate and GABA concentrations in episodic memory relevant brain regions (medial prefrontal cortex and precuneus) of T2D patients and matched controls. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamps and memory performance was assessed using a face-profession associations test. T2D patients exhibited peripheral insulin resistance and had a decreased memory for face-profession associations as well as elevated GABA concentration in the medial prefrontal cortex but not precuneus. In addition, medial prefrontal cortex GABA concentration was negatively associated with memory performance suggesting that abnormal GABA levels in the medial prefrontal cortex are linked to the episodic memory decline that occurs in T2D patients.

Differential GABA concentration gradients are present in the edible parts of greenhouse melon (Cucumis melo L.) during all four seasonal croppings.

Food-derived gamma-aminobutyric acid (GABA) exhibits health-promoting benefits, and melon contain high GABA concentrations. Greenhouse melons (Cucumis melo L. "Earl's Favorite") cultivated in Japan have identical or more edible parts than cultivars in other countries, however GABA distribution and the effects of seasonal variations are unclear. Thus, the present study aimed to evaluate GABA concentration gradients in four seasonal melons and how glutamic acid (Glu) influences the establishment of these gradients. GABA concentration was significantly lower near the exocarp than in the peduncle, equator, and remnant style regions in most seasons. Glu and GABA concentrations showed similar trends and were significantly correlated near the remnant style. No significant differences in GABA and Glu concentration were detected at concyclic sites across horizontal sections. These data indicate that GABA and Glu concentration differs substantially along a vertical melon section, but less so along a horizontal section, among sampling regions, sites, and cropping season.

Mechanism of gamma-aminobutyric acid (GABA) production by a lactic acid bacterium in yogurt-sake

Abstract We examined the gamma-aminobutyric acid (GABA) content of various kinds of fermented alcoholic beverages, including sake, shochu and yogurt-sake, and found that yogurt-sake contains a high concentration of GABA, higher than the sum of the concentrations in the sake and yogurt starting materials. To investigate the GABA production mechanism, we isolated the lactic acid bacteria (LAB) probably responsible for GABA production in the liquor and identified Streptococcus thermophilus Hp as a high GABA-producer and S. thermophilus Lp as a low GABA-producer. Cell extract from S. thermophilus Hp showed much higher glutamate decarboxylase activity than that from S. thermophilus Lp. During production of yogurt-sake using commercially available sake and yogurt produced with S. thermophilus Hp, the GABA increased over time, while the l -Glu was almost completely consumed. Moreover, by using sake supplemented with l -Glu, we successfully elevated the GABA concentration in yogurt-sake. By contrast, no GABA production was detected in yogurt-sake prepared using S. thermophilus Lp. These results indicate that LAB with highly active glutamate decarboxylase is responsible for GABA production in yogurt-sake. Our findings suggest GABA-enriched drinks are easily produced using yogurt and provide potentially useful information for production of other GABA-enriched foods.

Characterization of incisional and inflammatory pain in rats using functional tools of MRI

Underlying mechanisms of hyperalgesia differ with regard to the pain entities, which are well-modeled in animals for systematic studies. However, neuroimaging in different animal pain models often lacks clinical relevance and consistency with behavioral studies, which hinders the translation of results. Whereas mechanical stimulation is commonly used to explore hyperalgesia in animals and humans, functional magnetic resonance imaging (fMRI) studies frequently use electrical or heat stimuli to evaluate brain responses relevant to pain and hyperalgesia.To characterize the magnetic resonance (MR) representations of mechanical hyperalgesia after incision and inflammation, we aimed to investigate whole brain functional activities during innocuous and noxious mechanical or electrical stimulation (IMS/NMS; IES/NES), as well as metabolite levels in the thalamus of rats at rest and during electrical stimulation.In behavioral experiments, animal models of pain showed significant mechanical hyperalgesia, with a peak 24h after both injuries, but lasting longer after inflammation. In imaging experiments, mechanical and electrical stimulation revealed a biphasic BOLD response upon noxious stimulation in pain models. Analyses of the BOLD signal changes revealed significantly higher activation in pain models compared to sham animals. Furthermore, significant differences were present upon NMS (but not NES) between incision and inflammation models in all the studied regions except for contralateral somatosensory cortex (S1) and cerebellum (Cb) (F's>4.14, p's<0.05). Additionally, MS (but not ES) induced unexpected bilateral activation of S1 in all three animal groups. Finally, MR spectroscopy (MRS) in the thalamus showed higher concentrations of gamma-aminobutyric acid in both pain models at rest and during stimulation.We conclude that employment of MS in fMRI studies could provide an informative correlate of mechanical hyperalgesia in inflammatory and incisional pain models and might be used to further assess mechanisms and treatments relevant for these clinical pain states.

V1 surface size predicts GABA concentration in medial occipital cortex

A number of recent studies have established a link between behavior and the anatomy of the primary visual cortex (V1). However, one often-raised criticism has been that these studies provide little insight into the mechanisms of the observed relationships. As inhibitory neural interactions have been postulated as an important mechanism for those behaviors related to V1 anatomy, we measured the concentration of inhibitory gamma-amino butyric acid (GABA) in the medial occipital cortex where V1 is located using magnetic resonance spectroscopy (MRS) and estimated the surface area of V1 using fMRI retinotopic mapping. We found a significant positive relationship between GABA concentration and V1 surface area. This relationship was present irrespective of whether the MRS voxel had a fixed size across participants or was proportionally sized to each individual's V1 surface area. Hence, individuals with a larger V1 had a higher GABA concentration in the medial occipital cortex. By tying together V1 size and GABA concentration, our findings point towards individual differences in the level of neural inhibition that might partially mediate the relationships between behavior and V1 neuroanatomy. In addition, they illustrate how stable microscopic properties of neural activity and function are reflected in macro-measures of V1 structure.

Is GABA neurotransmission enhanced in auditory thalamus relative to inferior colliculus?

Gamma-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central auditory system. Sensory thalamic structures show high levels of non-desensitizing extrasynaptic GABAA receptors (GABAARs) and a reduction in the redundancy of coded information. The present study compared the inhibitory potency of GABA acting at GABAARs between the inferior colliculus (IC) and the medial geniculate body (MGB) using quantitative in vivo, in vitro, and ex vivo experimental approaches. In vivo single unit studies compared the ability of half maximal inhibitory concentrations of GABA to inhibit sound-evoked temporal responses, and found that GABA was two to three times (P < 0.01) more potent at suppressing MGB single unit responses than IC unit responses. In vitro whole cell patch-clamp slice recordings were used to demonstrate that gaboxadol, a δ-subunit selective GABAAR agonist, was significantly more potent at evoking tonic inhibitory currents from MGB neurons than IC neurons (P < 0.01). These electrophysiological findings were supported by an in vitro receptor binding assay which used the picrotoxin analog [(3)H]TBOB to assess binding in the GABAAR chloride channel. MGB GABAARs had significantly greater total open chloride channel capacity relative to GABAARs in IC (P < 0.05) as shown by increased total [(3)H]TBOB binding. Finally, a comparative ex vivo measurement compared endogenous GABA levels and suggested a trend towards higher GABA concentrations in MGB than in IC. Collectively, these studies suggest that, per unit GABA, high affinity extrasynaptic and synaptic GABAARs confer a significant inhibitory GABAAR advantage to MGB neurons relative to IC neurons. This increased GABA sensitivity likely underpins the vital filtering role of auditory thalamus.

GABA Shapes the Dynamics of Bistable Perception

Sometimes, perception fluctuates spontaneously between two distinct interpretations of a constant sensory input. These bistable perceptual phenomena provide a unique window into the neural mechanisms that create the contents of conscious perception. Models of bistable perception posit that mutual inhibition between stimulus-selective neural populations in visual cortex plays a key role in these spontaneous perceptual fluctuations. However, a direct link between neural inhibition and bistable perception has not yet been established experimentally. Here, we link perceptual dynamics in three distinct bistable visual illusions (binocular rivalry, motion-induced blindness, and structure from motion) to measurements of gamma-aminobutyric acid (GABA) concentrations in human visual cortex (as measured with magnetic resonance spectroscopy) and to pharmacological stimulation of the GABAA receptor by means of lorazepam. As predicted by a model of neural interactions underlying bistability, both higher GABA concentrations in visual cortex and lorazepam administration induced slower perceptual dynamics, as reflected in a reduced number of perceptual switches and a lengthening of percept durations. Thus, we show that GABA, the main inhibitory neurotransmitter, shapes the dynamics of bistable perception. These results pave the way for future studies into the competitive neural interactions across the visual cortical hierarchy that elicit conscious perception.

Genetic manipulation of the γ‐aminobutyric acid (GABA) shunt in rice: overexpression of truncated glutamate decarboxylase (GAD2) and knockdown of γ‐aminobutyric acid transaminase (GABA‐T) lead to sustained and high levels of GABA accumulation in rice kernels

Gamma-aminobutyric acid (GABA) is a non-protein amino acid commonly present in all organisms. Because cellular levels of GABA in plants are mainly regulated by synthesis (glutamate decarboxylase, GAD) and catabolism (GABA-transaminase, GABA-T), we attempted seed-specific manipulation of the GABA shunt to achieve stable GABA accumulation in rice. A truncated GAD2 sequence, one of five GAD genes, controlled by the glutelin (GluB-1) or rice embryo globulin promoters (REG) and GABA-T-based trigger sequences in RNA interference (RNAi) cassettes controlled by one of these promoters as well, was introduced into rice (cv. Koshihikari) to establish stable transgenic lines under herbicide selection using pyriminobac. T₁ and T₂ generations of rice lines displayed high GABA concentrations (2-100 mg/100 g grain). In analyses of two selected lines from the T₃ generation, there was a strong correlation between GABA level and the expression of truncated GAD2, whereas the inhibitory effect of GABA-T expression was relatively weak. In these two lines both with two T-DNA copies, their starch, amylose, and protein levels were slightly lower than non-transformed cv. Koshihikari. Free amino acid analysis of mature kernels of these lines demonstrated elevated levels of GABA (75-350 mg/100 g polished rice) and also high levels of several amino acids, such as Ala, Ser, and Val. Because these lines of seeds could sustain their GABA content after harvest (up to 6 months), the strategy in this study could lead to the accumulation GABA and for these to be sustained in the edible parts.

Genotype and environment influence gamma aminobutyric acid concentration in short-season soybean

Morrison, M. J., Frégeau-Reid, J. A. and Cober, E. R. 2012. Genotype and environment influence gamma aminobutyric acid concentration in short-season soybean. Can. J. Plant Sci. 92: 1093–1100. Gamma aminobutyric acid (GABA) is a four-carbon, non-structural protein found ubiquitously in life forms on the planet. In plants, it is produced in the cytosol in response to stresses, via the α-decarboxylation of glutamate by the enzyme glutamate decarboxylase. In studies, foods made from soybean (Glycine max L. Merr), with high GABA concentration, have reduced high blood pressure. Our objective was to determine if there were genotypic differences for GABA concentration among a series of short-season soybean cultivars. A historical series of 16 cultivars released from 1934 to 2000 was grown in a randomized complete block design with four replications across 3 yr at the Central Experimental Farm in Ottawa, Canada. Seed was harvested for yield and a sample taken to determine seed weight, protein, oil, L-glutamate (L-Glu) and GABA concentrations. There were significant differences among cultivars for all parameters and significant differences among years for all parameters except L-Glu. GABA was positively correlated with protein concentration, L-Glu and seed yield. There was a threefold difference in GABA concentration between the highest and lowest cultivars, but no clear relationships to weather parameters were identified. GABA concentration was determined to be moderately heritable (44%) indicating that new cultivars with higher concentrations could readily be developed. Soybean cultivars with higher GABA concentration, as part of the diet, may provide a means to reduce or prevent hypertension.

Individual Differences in Subconscious Motor Control Predicted by GABA Concentration in SMA

Subliminal visual stimuli affect motor planning, but the size of such effects differs greatly between individuals. Here, we investigated whether such variation may be related to neurochemical differences between people. Cortical responsiveness is expected to be lower under the influence of more of the main inhibitory neurotransmitter, GABA. Thus, we hypothesized that, if an individual has more GABA in the supplementary motor area (SMA)--a region previously associated with automatic motor control--this would result in smaller subliminal effects. We measured the reversed masked prime--or negative compatibility--effect, and found that it correlated strongly with GABA concentration, measured with magnetic resonance spectroscopy. This occurred specifically in the SMA region, and not in other regions from which spectroscopy measurements were taken. We replicated these results in an independent cohort: more GABA in the SMA region is reliably associated with smaller effect size. These findings suggest that, across individuals, the responsiveness of subconscious motor mechanisms is related to GABA concentration in the SMA.

Isolation of Marine Yeasts Collected from the Pacific Ocean Showing a High Production of γ-Aminobutyric Acid

Marine yeasts were collected from coastal and deep sea areas in the Pacific Ocean and the Sea of Japan around central and northern Japan to prepare a novel type of natural seasoning. It was found that one of the marine yeasts collected from the Pacific Ocean off Hachinohe showed a high concentration of gamma-aminobutyric acid (GABA) in its extract, about 7-10 times higher than those of commercially available bread yeast and other marine yeasts. The marine yeast isolated and named Hachinohe No. 6 catalyzed the reaction from monosodium glutamate to GABA only in the presence of glucose. Subsequently, several marine yeasts belonging to the genera Pichia and Candida were found to have such catalytic activities, but not those belonging to the genus Saccharomyces. Isolate Hachinohe No. 6 was found to have the highest catalytic activity among the yeasts examined in this study.

GABAA receptors present higher affinity and modified subunit composition in spinal motor neurons from a genetic model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a neurodegenerative disease characterized by the selective degeneration of motor neurons in the spinal cord, brainstem and cerebral cortex. In this study we have analysed the electrophysiological properties of GABA(A) receptors and GABA(A) alpha1 and alpha2 subunits expression in spinal motor neurons in culture obtained from a genetic model of ALS (G93A) and compared with transgenic wild type SOD1 (SOD1) and their corresponding non transgenic litter mates (Control). Although excitotoxic motor neuron death has been extensively studied in relation to Ca(2+)-dependent processes, strong evidence indicates that excitotoxic cell death is also remarkably dependent on Cl(-) ions and on GABA(A) receptor activation. In this study we have analysed the electrophysiological properties of GABA(A) receptors and the expression of GABA(A)alpha(1) and alpha(2) subunits in cultured motor neurons obtained from a genetic model of amyotrophic lateral sclerosis (G93A) and compared them with transgenic wild-type Cu,Zn superoxide dismutase and their corresponding non-transgenic littermates (Control). In all tested motor neurons, the application of gamma-aminobutyric acid (GABA) (0.5-100 mum) evoked an inward current that was reversibly blocked by bicuculline (100 mum), thus indicating that it was mediated by the activation of GABA(A) receptors. Our results indicate that the current density at high GABA concentrations is similar in control, Cu,Zn superoxide dismutase and G93A motor neurons. However, the dose-response curve significantly shifted toward lower concentration values in G93A motor neurons and the extent of desensitization also increased in these neurons. Finally, multiplex single-cell real-time polymerase chain reaction and immunofluorescence revealed that the amount of GABA(A)alpha(1) subunit was significantly increased in G93A motor neurons, whereas the levels of alpha(2) subunit were unchanged. These data show that the functionality and expression of GABA(A) receptors are altered in G93A motor neurons inducing a higher Cl(-) influx into the cell with a possible consequent neuronal excitotoxicity acceleration.

Increased GABA Levels in Medial Prefrontal Cortex of Young Adults with Narcolepsy

To explore absolute concentrations of brain metabolites including gamma amino-butyric acid (GABA) in the medial prefrontal cortex and basal ganglia of young adults with narcolepsy. Proton magnetic resonance (MR) spectroscopy centered on the medial prefrontal cortex and the basal ganglia was acquired. The absolute concentrations of brain metabolites including GABA and glutamate were assessed and compared between narcoleptic patients and healthy comparison subjects. Sleep and Chronobiology Center at Seoul National University Hospital; A high strength 3.0 Tesla MR scanner in the Department of Radiology at Seoul National University Hospital. Seventeen young adults with a sole diagnosis of HLA DQB1 0602 positive narcolepsy with cataplexy (25.1 +/- 4.6 years old) and 17 healthy comparison subjects (26.8 +/- 4.8 years old). N/A. Relative to comparison subjects, narcoleptic patients had higher GABA concentration in the medial prefrontal cortex (t = 4.10, P <0.001). Narcoleptic patients with nocturnal sleep disturbance had higher GABA concentration in the medial prefrontal cortex than those without nocturnal sleep disturbance (t = 2.45, P = 0.03), but had lower GABA concentration than comparison subjects (t = 2.30, P = 0.03). The current study reports that young adults with narcolepsy had a higher GABA concentration in the medial prefrontal cortex, which was more prominent in patients without nocturnal sleep disturbance. Our findings suggest that the medial prefrontal GABA level may be increased in narcolepsy, and the increased medial prefrontal GABA might be a compensatory mechanism to reduce nocturnal sleep disturbances in narcolepsy.

Germinated brown rice extract shows a nutraceutical effect in the recovery of chronic alcohol-related symptoms.

Chronic ethanol abuse can cause liver damage and unfavorable lipid profiles in humans and rodents. Phytonutrients have the potential to partially reverse some of the adverse effects of alcoholism. In this study, a germinated brown rice grown under conditions that favor high concentrations of gamma-aminobutyric acid (GABA) was evaluated for protective effects against the toxic consequences of chronic ethanol use. Serum and hepatic lipid concentrations and enzymes indicative of liver damage were determined in mice chronically administered ethanol. Balb/c mice were fed with either AIN-76 diet (control), control diet plus ethanol, or control diet plus ethanol and supplemental brown rice extract for 30 days. The extract naturally contained 841 nmol GABA per milliliter and was prepared from germinated brown rice. Serum low-density lipoprotein cholesterol (LDL-C), liver aspartate aminotransferase, and liver alanine aminotransferase levels were increased in mice administered ethanol, but not in mice given ethanol and brown rice extract. The brown rice extract significantly increased serum and liver high-density lipoprotein cholesterol (HDL-C) concentrations. Furthermore, administration of the extract prevented ethanol-induced increases in liver triglyceride and total cholesterol concentrations. These findings raise the possibility that brown rice extracts containing a high level of GABA may have a nutraceutical role in the recovery from and prevention of chronic alcohol-related diseases.