Aihide Yoshino

Association study of brain-derived neurotrophic factor gene polymorphism and alcoholism.

OBJECTIVE Brain-derived neurotrophic factor (BDNF) influences dopamine and serotonin neurotransmitters that are heavily linked to addiction. A quantitative trait loci study indicated that genes localized to 11p13, where the BDNF gene is mapped (11p13-15), increase the risk for severe alcohol withdrawal. Moreover, a recent study using a pooled-sample microarray suggested that the BDNF gene locus was included in the loci that were shown to be associated with drug abuse. These lines of evidence suggested that BDNF might play some role in the development of or vulnerability to alcoholism and/or clinical characteristics of alcoholic individuals. METHODS The alcoholic subjects consisted of 377 male Japanese patients. A structured interview was used to obtain social background, drinking history, history of violence while intoxicated, history of alcohol withdrawal, and family history of alcoholism. The control group consisted of 336 nonalcoholic male subjects. Genotyping of the G196A polymorphism of the BDNF gene was done by polymerase chain reaction (PCR)-restriction fragment length polymorphism method. RESULTS Genotype and allele distributions of the BDNF gene polymorphism did not differ significantly between alcoholic and control subjects. However, comparing clinical characteristics across G196A genotypes, we found that alcoholic subjects with violent tendencies and a history of delirium tremens had a significantly higher frequency of AA genotypes and A allele frequencies than those without them. Moreover, alcoholic subjects with the A allele had earlier onset of the disease than those without it. CONCLUSIONS These results indicate that BDNF gene polymorphism might modify phenotypes of alcoholism.

Association of a polymorphism of the 5HT2A receptor gene promoter region with alcohol dependence

Approximately 10% of Japanese alcoholics develop their disease despite having an inactive form of aldehyde dehydrogenase-2 (ALDH2),1 known as a genetic deterrent of heavy drinking due to adverse reactions after drinking.2 Such alcoholics are considered to be advantageous in genetic research because they should show reduced heterogeneity and possess genetic factors conferring susceptibility to alcohol dependence. Examination of the −1438 A/G polymorphism of the serotonin 2A (5HT2A) receptor gene in 225 Japanese alcoholics with inactive ALDH2 revealed the presence of significantly more of the G allele than was found in 361 control subjects. The frequency of the G allele in 282 alcoholics with active ALDH2 fell between the G allele frequencies of controls and subjects with inactive ALDH2. These data suggest that although the effect is relatively small, genetic variability in the 5HT2A receptor is involved in the development of alcohol dependence.

Plasma orexin-A is lower in patients with narcolepsy.

Recently identified hypothalamic peptides called orexins (or hypocretins) have been implicated in the sleep-wake cycle and in sleep disorder narcolepsy. Neuropathological studies have shown that in patients with narcolepsy, global reduction in the expression of orexins occurs due to the loss of orexin neurons in the hypothalamus. Cerebrospinal fluid analysis has confirmed a reduced or undetectable level of orexin-A in most narcolepsy patients. In this study, measurement of plasma orexin showed significantly lower concentrations in patients with narcolepsy than in age- and gender-matched normal controls. These data suggest that low levels of orexin-A in plasma could serve as a biological marker for narcolepsy.

Telepsychiatry: assessment of televideo psychiatric interview reliability with present‐ and next‐generation internet infrastructures

Objective: We assessed the reliability of remote video psychiatric interviews conducted via the internet using narrow and broad bandwidths.

A topographic electrophysiologic study of mental rotation

Mental rotation is a task performed when subjects are requested to determine whether two stimuli presented in turn have the same shape (congruency) or a mirror-image shape (incongruency) regardless of any difference in orientation. We compared event-related potentials during mental rotation tasks with narrow and wide angular disparities between the two stimuli to identify electrophysiologic correlates of mental rotation. When angular disparity was wide, a prominent negative component arose 438 ms after the second stimulus. A statistically significant difference detected between amplitudes of the negative components under narrow- and wide-angle conditions was maximal in the right parietal region, suggesting that processing of mental rotation is a right parietal dominant function.

Autonomic arousal in cognitive conflict resolution

Although cognitive efforts were reported to elicit global autonomic arousal, which cognitive processes associate with autonomic arousal has not been clear. We investigated autonomic arousal using event-related skin conductance responses (SCRs) during the Stroop color-word task. After baseline SCR deflections were determined in each trial block, SCRs were compared between cognitive conflict conditions (incongruent vs. congruent stimuli), between tasks assigned (word reading vs. color naming), and between erroneous and correct responses. Baseline SCRs were significantly greater at the beginning of each trial block. SCRs were significantly greater with incongruent than congruent stimuli while SCRs differed little between word reading and color naming. SCRs were greater when responses were incorrect. The results suggested that autonomic arousal occurs during cognitive conflict resolution in addition to mental set adoption for a task and in error awareness.

Interhemispheric difference in emotional response without awareness

To investigate interhemispheric differences concerning unconscious human emotional responses processed, we measured human skin conductance responses (SCRs) to masked (unseen) emotional stimuli presented to left or right visual fields. Backward masking was used to preclude conscious processing of emotional stimuli. Masked negative or neutral emotional pictures from the International Affective Picture System (IAPS) were presented to 11 right-handed male volunteers. Mean SCR for negative emotional stimuli presented to the left visual field was significantly greater than mean SCRs for negative emotional stimuli to the right visual field and for neutral stimuli to the left or right visual fields. Thus, the right rather than the left hemisphere appears to respond to preattentive negative emotional stimuli.

Reliability and validity of the Japanese version of the tridimensional personality questionnaire among university students

The Tridimensional Personality Questionnaire (TPQ) is a self-rating questionnaire, based on a general biosocial theory, for the clinical description and classification of both normal and abnormal personality variants. It was translated into Japanese and administered with the General Health Questionnaire (GHQ) and the 10-item version of the Social Desirability Scale (SDS) to 450 university students on two occasions 2 months apart. Pearson Product-Moment Correlation Coefficients and kappa-coefficients between TPQ scale scores for the two occasions were significantly high, as were Cronbachs alpha-coefficients of TPQ scales and subcategories at the first wave. Correlations between the TPQ scale score and GHQ and SDS scores were negligible. The TPQ thus appears to have test-retest reliability and content validity among a Japanese student population; it is uninfluenced by psychiatric morbidity or social desirability.

Effects of slow repetitive transcranial magnetic stimulation on heart rate variability according to power spectrum analysis

We examined whether repetitive transcranial magnetic stimulation (rTMS) at a low rate could influence autonomic function, specially heart rate variability (HRV) by power spectrum analysis. We studied 16 healthy male volunteers as a stimulation group and 16 others as a sham group. The stimulation group received magnetic stimulations from a circular coil over Cz at a frequency of 0.2 Hz and an intensity presenting 90% of the motor threshold. Experiments in both groups included four daily sessions; at each, a train of 70 stimuli was delivered over 350 s. HRV of low-frequency power (LF) in a standing position and high-frequency power (HF) in a supine position were measured before and after each session. After stimulation, HF and LF powers were significantly increased. After sham stimulation, the power of HF but not that of LF significantly increased. Neither actual nor sham stimulation produced a long-term effect detectable on day 5. The finding of transiently increased LF power following actual but not sham stimulation suggests that rTMS may activate the sympathetic nervous system.

Relationships between temperament dimensions in personality and unconscious emotional responses

BACKGROUND In addition to character dimensions, personality includes temperament dimensions, defined as individual differences in implicit associative learning responses to environmental stimuli processed by unconscious memories. We examined whether temperament dimensions were associated with patterns of unconscious emotional responses of an autonomic nature. METHODS From 70 healthy men, high and low novelty-seeking (NS) groups and high and low harm-avoidance (HA) groups were selected using scores on the Tridimensional Personality Questionnaire measuring temperament dimensions. Emotionally negative, neutral, and positive visual stimuli were presented subliminally using backward masking, and skin conductance responses (SCRs) were measured as an autonomic index of emotional responses. Skin conductance responses to the three emotional stimulus conditions were compared between groups. RESULTS Skin conductance responses in the high NS group were significantly greater than in the low NS group when positive or negative emotional stimuli were presented but not neutral stimuli. Skin conductance responses in the high HA group were significantly greater than in the low HA group for stimuli of all three valences. CONCLUSIONS Autonomic response patterns to unconscious emotional perception differed between NS and HA, suggesting that different dimensions of temperament may be associated with different patterns of unconscious emotional responses. Novelty seeking and HA may be associated with specificity and susceptibility of preattentive emotional perception, respectively.