Dysfunctional Patterns of Gamma-Band Activity in Response to Human Faces Compared to Non-Facial Stimuli in Patients with Schizophrenia.

OBJECTIVE: Healthy individuals show stronger gamma-band activities (GBAs) for socially relevant stimuli (human faces) than for non-relevant ones. This study aimed to examine whether this gamma-band preference occurs in patients with schizophrenia. METHODS: EEG was recorded for 24 patients with schizophrenia and 23 healthy controls while they viewed pictures of human faces, chairs, and nature scenes. The spectral powers of high-beta (20-30 Hz) and gamma (30-80 Hz) frequencies were analyzed along 3 midline cortical regions, and phase synchronization was calculated. RESULTS: Compared to the response to non-facial stimuli, higher event related deactivation to facial stimuli was observed for the high-beta frequency across groups. For the gamma frequency, early-stage GBA was increased and late-stage GBA was decreased for all 3 stimuli in patients with schizophrenia compared to healthy controls. Preferential GBA patterns (100-200 and 200-300 ms) were found in healthy controls, but not in patients with schizophrenia. Significant correlation existed between negative symptoms and GBA in the frontal region for chair and scene stimuli. There was no significant intergroup difference in phase synchronization pattern. CONCLUSION: Our results suggest that patients with schizophrenia have deficits in the preferential pattern of GBA for human faces and the deficits in the preferential pattern were mainly influenced by over-response to socially non-relevant stimuli.

Immunostimulatory effect of fermented red ginseng in the mouse model.

In this study, Woongjin fermented red ginseng extract (WFRG) was evaluated for its potential ability to act as an adjuvant for the immune response of mice. For the in vitro study, macrophages were treated with serial concentrations (1 µg/mL, 10 µg/mL, and 100 µg/mL) of WFRG. For in vivo studies, mice were administered different concentrations (10 mg/kg/day, 100 mg/kg/day, and 200 mg/kg/day) of WFRG orally for 21 days. In vitro, the production of nitric oxide and TNF-α by RAW 264.7 cells increased in a dose-dependent manner. In vivo, WFRG enhanced the proliferation of splenocytes induced by two mitogens (i.e., concanavalin A and lipopolysaccharide [LPS]) and increased LPS-induced production of TNF-α and IL-6, but not IL-1ß. In conclusion, WFRG has the potential to modulate immune function and should be further investigated as an immunostimulatory agent.

Flavobacterium ginsengisoli sp. nov., isolated from soil of a ginseng field.

A novel bacterial strain, designated DCY54(T), was isolated from a field cultivated with ginseng in Yongin, Republic of Korea. Cells were Gram-reaction-negative, yellow-pigmented, rod-shaped, non-spore-forming, and strictly aerobic. They were motile by gliding and produced flexirubin-type pigments. Growth occurred optimally at 25-30 °C, at pH 5.0-7.0 and in the presence of 0-1 % NaCl. The 16S rRNA sequence analysis demonstrated that strain DCY54(T) was most closely related to Flavobacterium defluvii EMB117(T) (96.9 %). The only isoprenoid quinone of strain DCY 54(T) was menaquinone-6 (MK-6) and the major polar lipids were phosphatidylethanolamine, one unidentified aminolipid and one unidentified lipid. The major cellular fatty acids (>15 %) were iso-C15 : 0, summed feature 3 (comprising C16 : 1ω7c and/or iso-C15 : 0 2-OH) and C16 : 0. The DNA G+C content was 33.3 mol%. Phylogenetic inference and phenotypic data supported affiliation of strain DCY54(T) to the genus Flavobacterium. Several physiological and biochemical tests differentiated strain DCY54(T) from the species of the genus Flavobacterium with validly published names. On the basis of data from a polyphasic study, strain DCY54(T) represents a novel species of the genus Flavobacterium for which the name Flavobacterium ginsengisoli sp. nov. is proposed. The type strain is DCY54(T) ( = KCTC 23318(T) = JCM 17336(T)).

Gender difference in event related potentials to masked emotional stimuli in the oddball task.

OBJECTIVE: We investigated gender differences in event-related potential (ERP) responses to subliminally presented threat-related stimuli. METHODS: Twenty-four participants were presented with threat-related and neutral pictures for a very brief period of time (17 ms). To explore gender differences in ERP responses to subliminally presented stimuli, we examined six ERP components [P1, N170, N250, P300, Early Posterior Negativity (EPN) and Late Positive Potential (LPP)]. RESULTS: The result revealed that only female participants showed significant increases in the N170 and the EPN in response to subliminally presented threat-related stimuli compared to neutral stimuli. CONCLUSION: Our results suggest that female participants exhibit greater cortical processing of subliminally presented threat-related stimuli than male participants.

Neuropsychological correlates of the P300 in patients with Alzheimer's disease.

OBJECTIVES: The P300 is a useful psychophysiological index that reflects cognitive functions; however, the relationship between P300 indices and neuropsychological tests in Alzheimer's disease (AD) patients is unclear. METHODS: Thirty-one AD patients and 31 elderly normal control (NC) subjects were recruited. Age and education level were matched between the two groups. The relationship between the P300 and the Korean version of the Consortium to Establish a Registry for Alzheimer's disease (CERAD-K) assessment packet (including 11 neuropsychological tests) was examined in AD patients. RESULTS: Compared to the NC subjects, the AD patients exhibited significantly decreased P300 amplitudes; however, there was no significant difference between the two groups in terms of P300 latency. After a permutation-based correction for multiple tests, P300 amplitudes at the Cz and Pz electrodes were significantly correlated with performance on the word list recognition, constructional praxis, and word fluency neuropsychological tests in the AD patients. Additionally, P300 latencies at the Pz and C6 electrodes were also significantly correlated with performance on the Mini-Mental State Examination, CERAD-K version (MMSE-K), and Trail Making Test part A (TMT-A) neuropsychological tests in the AD patients. CONCLUSIONS: The results suggest that the P300 is responsive to the deterioration of language, memory, and executive functions observed in AD patients. Although there was no significant difference between the AD patients and NC subjects in the P300 latency, P300 latency has been shown to reflect impaired global cognition and attention deficits associated with AD. Our results suggest that P300 indices could be used as biological markers that indicate impaired neuropsychological functions in AD patients.

When crowding meets binocular rivalry: challenges for object perception.

Both crowding and binocular rivalry impair object perception, but their influence on object perception has so far only been investigated in separate fields. Three experiments investigated the joint influences of crowding and rivalry on object perception (orientation discrimination). Experiment 1 investigated how crowding and rivalry influence orientation discrimination together. Experiment 2 tested whether rivalry between flankers affects crowding using an orientation discrimination task. Experiment 3 tested whether crowding affects the temporal dynamics of the rivalry between a target and a rival stimulus. In Experiment 1, judgments of target orientation were more impaired when crowding and rivalry were simultaneously induced than when they were separately induced and their effects were combined. In Experiment 2, judgments of target orientation were impaired even when flankers were undergoing rivalry, thus highlighting the importance of the presence of flankers. Experiment 3 showed that flankers presented in the neighborhood of a target undergoing rivalry shortened target dominance and prolonged target suppression. The augmented impairments of object perception found in Experiments 1 and 3 suggest that crowding and rivalry interact, presumably through signal suppression. The adverse effect of flankers shown in Experiment 2 suggests that inappropriate feature integration may have additionally contributed to this interaction.

Clinical implications of quantitative electroencephalography and current source density in patients with Alzheimer's disease.

This study examined whether quantitative electroencephalography (qEEG) and current source density (CSD) can be used to evaluate symptom severity in Alzheimer's disease (AD) patients. Thirty AD patients (13 mild and 17 moderate severity) and 30 normal control (NC) subjects were recruited. The Korean version of the Consortium to Establish a Registry for Alzheimer's Disease Assessment Packet and the Global Deterioration Scale were measured. qEEG and CSD data were analyzed in five frequency bands: delta (1-3 Hz), theta (4-7 Hz), alpha (8-12 Hz), beta (13-25 Hz), and gamma (30-50 Hz). Compared with the NC subjects, the moderate AD patients had significantly increased theta and decreased beta power. Compared with the mild AD patients, the moderate AD patients had significantly decreased beta power. In the AD patients, the theta power was significantly correlated with a poor performance for global cognition; however, beta power was positively correlated with a good performance for global cognition, attention, memory, visuospatial function, and executive function. The CSD of the theta band in the superior temporal gyrus, transverse temporal gyrus, insula, postcentral gyrus, cuneus, and lingual gyrus was significantly different between NC subjects and moderate AD patients and between mild and moderate AD patients. The theta CSD of these regions was significantly correlated with a poor performance for global cognition, memory, visuospatial function, execution, and language. The results suggest that qEEG and the CSD of the theta and beta bands are useful biological markers in AD patients.

Reduced source activity of event-related potentials for affective facial pictures in schizophrenia patients.

The ability to recognize facial affect is impaired in schizophrenia patients. This study compared source activities of the event-related potentials (ERPs) for affective facial pictures between schizophrenia patients and healthy controls. Twenty-three schizophrenia patients (11 females) and 24 healthy controls (12 females) were recruited. The standardized low-resolution brain electromagnetic tomography (sLORETA) source activities of four ERP components (P100, N170, N250, and P300) were compared between schizophrenia patients and healthy controls in response to fearful, happy, and neutral facial expressions. Group differences of sLORETA source activities were found only for the N170 component in response to the fearful face. Source activities in the middle frontal gyrus and inferior frontal gyrus were lower in schizophrenia patients compared to healthy controls. Source activity in the insula was lower in male schizophrenia patients compared to male healthy controls. Source activities in the superior temporal gyrus, middle temporal gyrus, insula and inferior frontal gyrus were lower in male compared to female schizophrenia patients. However, there was no gender difference on ERP source activities in the healthy controls. These results support the hypothesis that schizophrenia patients have reduced N170 current source density in response to fearful faces. The area exhibiting reduced current source density includes the frontal and temporal cortex. The present results suggest that there may be gender differences in facial affect processing in schizophrenia patients.

Biotransformation of Ginsenoside Rb1 to Prosapogenins, Gypenoside XVII, Ginsenoside Rd, Ginsenoside F2, and Compound K by Leuconostoc mesenteroides DC102.

Ginsenoside Rb1is the main component in ginsenosides. It is a protopanaxadiol-type ginsenoside that has a dammarane-type triterpenoid as an aglycone. In this study, ginsenoside Rb1 was transformed into gypenoside XVII, ginsenoside Rd, ginsenoside F2 and compound K by glycosidase from Leuconostoc mesenteroides DC102. The optimum time for the conversion was about 72 h at a constant pH of 6.0 to 8.0 and the optimum temperature was about 30℃. Under optimal conditions, ginsenoside Rb1 was decomposed and converted into compound K by 72 h post-reaction (99%). The enzymatic reaction was analyzed by highperformance liquid chromatography, suggesting the transformation pathway: ginsenoside Rb1→ gypenoside XVII and ginsenoside Rd→ginsenoside F2→compound K.

Flavobacterium ginsengiterrae sp. nov., isolated from a ginseng field.

A novel strain of Flavobacterium, DCY55(T), a Gram-negative, yellow-pigmented, rod-shaped, non-spore-forming and gliding-motile bacterium, was isolated from the soil of a ginseng field in South Korea. Phylogenetic analysis, based on the 16S rRNA sequence, demonstrated that strain DCY55(T) belongs to the genus Flavobacterium within the family Flavobacteriaceae. Strain DCY55(T) showed the highest similarity with F. johnsoniae UW101(T) (97.1%), F. ginsenosidimutans THG 01(T) (96.8%), F. defluvii EMB 117(T) (96.6%), F. banpakuense 15F3(T) (96.3%) and F. anhuiense D3(T) (95.8%). Chemotaxonomic results showed that strain DCY55(T) predominantly contains menaquinone MK-6, that its DNA G+C content is 36.1mol%, and that its major cellular fatty acids are iso-C(15:0), summed feature 3 (comprising iso-C(15:0) 2-OH and/or C(16:1) ω 7c) and C(16:0). The chemotaxonomic and genotypic characteristics support the taxonomic classification of strain DCY55(T) to the genus Flavobacterium. The results of physiological and biochemical tests confirmed that strain DCY55(T) is distinct from previously validated species. We conclude that strain DCY55(T) should be classified as a novel species of the genus Flavobacterium, for which the name Flavobacterium ginsengiterrae sp. nov. is proposed, with the type strain DCY55(T) (=KCTC 23319(T) = JCM 17337(T)).

The loudness dependence of the auditory evoked potential (LDAEP) as a predictor of the response to escitalopram in patients with generalized anxiety disorder.

RATIONALE: The loudness dependence of the auditory evoked potential (LDAEP) has been proposed as a potential biological marker of central serotonergic activity. This study aimed to test the hypothesis that the LDAEP can be used to predict the response to escitalopram in patients with GAD. METHOD: Twenty-five patients with GAD were recruited. Scores on the Hamilton Anxiety Rating Scale (HAM-A), Clinical Global Impression-Severity Scale (CGI-S), and Beck Anxiety Inventory (BAI) were evaluated. To evaluate the LDAEP, the auditory event-related potential was measured before beginning medication. Peak-to-peak N1/P2 amplitudes and current source densities were calculated at five stimulus intensities, and the LDAEP was calculated as the linear-regression slope. The current source densities of the evoked potentials were analyzed by standardized low-resolution brain electromagnetic tomography (sLORETA). The loudness dependence of the current densities (sLORETA-LDAEP) was also calculated. RESULTS: The pretreatment LDAEPs of all patients were positively correlated with the CGI-S response rates at 4 and 8 weeks, and with the HAM-A and BAI response rates at 8 weeks. The sLORETA-LDAEPs were positively correlated with the HAM-A response rates after 8 weeks of treatment. The HAM-A and CGI response rates at 8 weeks were higher in patients with a strong pretreatment LDAEP than in those with a weak LDAEP. CONCLUSIONS: The present study revealed that GAD patients with a favorable response to escitalopram treatment are characterized by a stronger pretreatment LDAEP. Measurement of the LDAEP appears to provide useful clinical information for predicting treatment responses in patients with GAD.

A role in the regulation of transcription by light for RCO-1 and RCM-1, the Neurospora homologs of the yeast Tup1-Ssn6 repressor.

The activation of gene transcription by light is transient since light-dependent mRNA accumulation ceases after long exposures to light. This phenomenon, photoadaptation, has been observed in plants and fungi, and allows the perception of changes in light intensities. In the fungus Neurosporacrassa photoadaptation involves the transient binding of the photoresponsive White Collar Complex (WCC) to the promoters of light-regulated genes. We show that RCO-1 and RCM-1, the Neurospora homologs of the components of the yeast Tup1-Ssn6 repressor complex, participate in photoadaptation. Mutation in either rco-1 or rcm-1 result in high and sustained accumulation of mRNAs for con-10 and other light-regulated genes after long exposures to light. The mutation of rco-1 increased the sensitivity to light for con-10 activation and delayed synthesis and/or degradation of con-10 and con-6 mRNAs without altering the amount or the light-dependent phosphorylation of the photoreceptor WC-1. RCO-1 and RCM-1 are located in the Neurospora nuclei were they regulate gene transcription. We show that RCO-1 and RCM-1 participate in the light-transduction pathway of Neurospora and has a role in photoadaptation by repressing gene transcription after long exposures to light.

Dysfunctional gamma-band activity during face structural processing in schizophrenia patients.

This study investigated gamma-band activity (GBA) and its phase synchrony in schizophrenia patients viewing human faces. Twenty-five schizophrenia patients were compared with 25 normal controls. Event-related potentials were recorded from all participants while they were viewing emotionally neutral faces. The spectral power and phase synchrony in the frequency band from 30 to 55 Hz were analyzed in midline electrodes (FCz, Cz, CPz, Pz, and POz). Three windows of interest, which showed discernable GBA differences between schizophrenia patients and normal controls, were selected by visual inspection: 0-100 ms (30-33 Hz), 250-300 ms (34-38 Hz), and 700-800 ms (40-45 Hz). And the phase synchrony of gamma band was analyzed. Repeated-measures ANOVA revealed that the GBA was lower in schizophrenia patients than in normal controls. Also there were significant location and time differences in GBA. GBA was significantly lower in the schizophrenia patients than in the normal controls at around 700-800 ms at the FCz electrode. The frontal (FCz) and central (Cz) GBA were significantly correlated with the number of hospitalization, and the negative symptoms of schizophrenia, respectively. The phase synchronization was significantly lower at 200-300 ms in the schizophrenia patients than in the normal controls. These findings suggest that the schizophrenia patients have impaired GBA and gamma-band synchronization during face perception. Furthermore, our results also suggest that the decreased GBA observed at the midline cortex of schizophrenia patients is closely related to their negative symptoms and disease progress.

Event-related potential patterns and gender effects underlying facial affect processing in schizophrenia patients.

This study was designed to clarify the consecutive temporal mechanisms and gender effects underlying facial affect processing in patients with schizophrenia and normal controls through electrophysiological measurements. The following four event-related potential (ERP) components were chosen as indexes of four distinct stages: P100, N170, N250, and P300. A total of 38 schizophrenia patients (22 females) and 38 normal controls (20 females) were recruited. ERPs were recorded while participants identified emotions in images of faces showing three different states: happy, fearful and neutral. The mean peak amplitude of N170 was significantly lower in schizophrenia patients than in normal controls. The mean peak amplitudes of N170 and N250 for fearful emotion were significantly higher than that for happy emotion. The latencies of N170, and P300 were longer in schizophrenia patients than in normal controls. Gender effects were found for P100 peak amplitude and N170 latency, and significant interactions with gender were found for P300 amplitudes and P100 latency. Our results provide evidences of the dysfunctional ERP patterns underlying facial affect processing in schizophrenia patients. Furthermore, the results suggest that gender could be an important controlling factor for facial affect processing in schizophrenia patients.

The loudness dependence of the auditory evoked potential (LDAEP) in schizophrenia, bipolar disorder, major depressive disorder, anxiety disorder, and healthy controls.

BACKGROUND: Serotonergic dysfunction in schizophrenia, bipolar disorder, major depressive disorder, anxiety disorder, and healthy controls was evaluated by measuring the activity of the loudness dependence of the auditory evoked potential (LDAEP). METHODS: The 357 subjects who were evaluated comprised 55 normal controls, 123 patients with major depressive disorder, 37 with bipolar disorder, 46 with schizophrenia, 37 with panic disorder (PD), 31 with generalized anxiety disorder (GAD), and 28 with post-traumatic stress disorder (PTSD). RESULTS: LDAEP was significantly stronger in healthy controls than in patients with either bipolar disorder (p=0.025) or schizophrenia (p=0.008), and significantly stronger in patients with major depressive disorder than in those with bipolar disorder (p=0.01) or schizophrenia (p=0.03). LDAEP did not differ significantly between patients with major depressive disorder and healthy control subjects (p=0.667), or between healthy control subjects and patients with anxiety disorder, including PD (p=0.469), GAD (p=0.664), and PTSD (p=0.167). CONCLUSION: The findings of the present study reveal that patients with major psychiatric disorders exhibit different strengths of LDAEP according to their serotonin-related pathology. Studies controlled for psychotropic medication, menstruation cycle, and smoking are needed.