Sunao Uchida, M.D., Ph.D.,
Vice-councilor of Research

Department of Psychophysiology,
Tokyo Institute of Psychiatry

We pursue human EEG oscillations and their physiological significances during sleep and wake, in health and disease.

Dr. Uchida received his M.D. from Shiga University of Medical Science in 1983, and Ph.D. from Tokyo Medical and Dental University in 1993, where he studied clincal psychiatry, electroencephalography, and sleep physiology, supervised by late Prof. R. Takahashi, late Prof. Y. Shimazono, Prof. Emeritus M. Toru, and Dr. Y. Atsumi. He also studied in the Department of Psychiatry, University of California at Davis with Professor Irwin Feinberg on sleep physiology and computer analysis of polysomnography in 1990-1992. In 1992, he started to work in the Department of Psychophysiology, Tokyo Institute of Psychiatry, and became vice-councilor of research in 1999. He also works as a visiting psychiatrist in the Department of Psychiatry, Tokyo Metropolitan Geriatric Hospital. He teaches as a visiting lecturer in Tokyo Institute of Technology, and Musashino Gakuen College. He likes jazz and football.


Colleagues:


Collaborators:


Visiting professors:

  • Einosuke Koga, M.D., Ph.D. (Prof Emeritus Tokyo Gakugei Univ)
  • Masato Matsuura, M.D., Ph.D. (Assist Prof Nihon Univ Hp - Psychiatry)
  • Jun Kohyama, M.D., Ph.D. (Assist Prof Tokyo Med Dent'l Univ - Pediatrics)
  • Yoshiro Okubo, M.D., Ph.D. (Prof Tokyo Med Dent'l Univ - Clinical Physiology)


Researchers who used to work with us:

  • Xin Tan, M.D., Ph.D. (University of California at Davis)
  • Yasuhiko Sudo, M.D., Ph.D. (Columbia University)


Research Interests:

    Human sleep physiology - Normal polysomnography and electrocorticography

    We have studied all-night fluctuations of EEG frequency bands and found that there are three frequency bands that show characteristic fluctuation patterns across the night. They are delta (0.3-3 Hz), sigma (12-16 Hz) and beta (20-28 Hz) frequencies. We are now studying their physiological significances in health and disease. In order to study generation mechanisms and functional rolls, we performed simultaneous recording of 15-O water positron emission tomography (PET) and EEG during the night in collaboration with National Center for Neurology and Psychiatry (Drs. Takayama, Uchiyama, Kajimura, Uema, Takahashi, Okawa and others). We also perform electrocorticogram recordings of natural sleep in epilepsy patients to see electrical activities in various cortical areas during sleep and wake in collaboration with Tokyo Metropolitan Neurological Hospital.

    Human sleep physiology - Normal magnetoencephalography (MEG)

    In collaboration with Dr. Andreas Ioannides in Riken institute (Wako), we recently started sleep MEG recording of normal human subjects.

    Sleep - Pharmacological effects

    Examining effects of CNS drugs on sleep EEG has several aspects. Firstly, one can know EEG spectral patterns caused by the drug. This kind of study is possible in wake condition. However, wake condition tend to have larger variance of noise level. For example, in order to eliminate external stimulus effects, subject is usually indicated to close the eyes. However, closing eyes makes reduces subject's vigilance level. Sometimes, pharmacological effect also promote this tendency. In such case, changes of EEG spectral components were difficult to interpret. Recording EEG during all night sleep, advantages in such sense. It provides a complete vigilance control and changes of sleep EEG is purely the pharmacological effect.
    Another aspect is that by using agents with relatively high neuro-receptor specificity, one could suspect functional role of neurotransmitter system in human sleep. We have tried, benzodiazepines, clonidine, anti-depressants, and anti-cholinergic drugs to see such effects.

    Narcolepsy

    Narcolepsy is relatively rare disease (prevalence approximately 0.16-0.59% in past Japanese studies), whose onset is normally in adolescence. It is characterized by repetitive sleep attack and clinical observable cataplexy. We work in collaboration with Dr. Yutaka Honda, the director of Seiwa Hospital, to record all night polysomnography of drug naive Narcolepsy patients. In this study, we try to find polysomnographic characteristics of Narcolepsy, especially those have diagnostic values.

    Epilepsy and sleep

    It's been known that sleep has a promoting effect on epilepsy. Inter ictal spike discharge (IISD) is usually increase their number during sleep. Many past studies indicate that the number of IISD fluctuate across all-night sleep. Such fluctuation closely correlate with sleep stages or some EEG frequency components. However, all past studies used standard surface EEG, which partially reflect actual number of IISD on the epileptic focus. We have performed all night electrocorticogram recordings of temporal epilepsy, from subdural electrodes attached on the surface of parahippocampal gyrus and basal temporal lobe. These recordings could detect more spike activities than surface EEG. Cz EEG was also simultaneously recorded. We, then, examined the relationship between medial temporal spike counts and EEG frequency components.

    Human medial temporal lobe electrophysiology

    Medial temporal lobe has drawn a lot of interests, since it has been know to be closely related to memory function. It's physiological property has been studied in detail in animals. However, electrophysological properties of human medial temporal lobe has not been studied in detail. By analyzing electrocorticogram data obtained from subdural electrodes attached on the surface of parahippocampal gyrus and basal temporal lobe, we reported two distinct oscillatory activities observed in the human medial temporal lobe. One is gamma frequency (30-150 Hz) and another is beta-1 frequency (10-20 Hz). Their functional significances are now studied.

    Roles of gamma oscillation - cortical information binding

    Classical neural network theory indicate that neurons (or neuronal groups) relating to specific information feature work together to construct internal representations of actual situations. However, there needs a physiological mechanism to bind separate neurons (or neuronal groups) representing different features [cf. von der Malsburg's review: Neuron 1999, 24: 95-104]. In late 1980's, it was found that neurons (or neuronal groups) synchronously oscillate between related fields in gamma band (Eckhorn et al. 1988, Gray et al. 1989). Thus, the temporal synchrony of gamma band has been focused on its functional role of feature binding. Several evidences to prove gamma band carry such a role have been found in human experiments as well. In a work with my colleague Dr. Nobuhide Hirai, we have found gamma oscillation in the human medial temporal cortex. Such oscillation was also found in occipital cortex (also by subdural electrode) in a epileptic case. We are now working on functional roles of this activity. Please also read my review paper in Japanese.

    ISTC funding project G-391: Novel methods for correction of brain functinos in depression and after antidepressant treatment

    This project is supported by ISTC (International Science and Technology Center), and has been carried out in I.S. Beritashvili Institute of Physiology, Tbilisi, Georgia.


Recent Publications (peer reviewed papers):

  • Uchida, S.,Nakayama, H., Maehara, T., Hirai, N., Arakaki, H., Nakamura, M., Nakabayashi,T., Shimizu, H. (2000) Suppression of gamma activity in the human medial temporal lobe by sevoflurane anesthesia. Neuroreport 11 39-42
  • Kajimura, N., Uchiyama, M., Takayama, Y., Uchida, S., Uema, T., Kato, M., Sekimoto, M., Watanabe, T., Nakajima, T., Horikoshi, S., Ogawa, K., Nishikawa, M., Hiroki, M., Kudo, Y., Matsuda, H., Okawa, M., Takahashi, K. (1999) Roles of midbrain and neocortex during human non-REM sleep assesed by PET. J. Neurosci. 19 10065-10073
  • Hirai, N. Uchida, S., Maehara, T., Okubo, Y., Shimizu, H. (1999) Beta-1 (10-20 Hz) cortical oscillations observed in the human medial temporal lobe. Neuroreport 10 3055-3059
  • Uchida, S., Feinberg I., March, J.D., Atsumi, Y., and Maloney, T. (1999). A comparison of period amplitude analysis and FFT power spectral analysis of all-night human sleep EEG. Physiol. Behav.67 (1), 121-131.
  • Hirai, N., Uchida, S., Maehara T., Okubo, Y., Shimizu, H. (1999). Enhanced gamma (30-150 Hz) frequency in the human medial temporal lobe. Neuroscience 90, 1149-1155.
  • Sudo, Y., Suhara, T., Suzuki, K., Okubo, Y., Yoshikawa, K., Uchida, S., Okauchi, T., Sasaki, Y., Matsushita M. (1999). Muscarinic receptor occupancy by biperiden in living human brain. Life Sci. 64. 99-104.
  • Tan, X., Uchida, S., Matsuura, M., Nishihara, K., Iguchi, Y., Kojima T. (1998). Benzodiazepine effects on human sleep EEG spectra: A comparison of triazolam and flunitrazepam. Life Sci. 63, 675-684.
  • Uchida, S., Takizawa, Y., Hirai, N., Ishiguro M. (1997). Human sleep electroencephalogram analysis based on the Instantaneous Maximum Entropy Method. IEICE Trans. Fundamentals E80-A, 965-970.
  • Uchida, S., Okudaira, N., Nishihara, K., Iguchi, Y., Tan X. (1996). Flunitrazepam effects on human sleep EEG spectra II: Sigma and beta alterations during NREM sleep. Life Sci. 59, PL117-120.
  • Uchida, S., Okudaira, N., Nishihara, K., Iguchi, Y. (1996). Flunitrazepam effects on human sleep EEG spectra: differences in NREM, REM and individual responses. Life Sci. 58, PL199-205.
  • Uchida, S., Matsuura, M., Ogata, S., Yamamoto, T., Aikawa N. (1996). Computerization of Fujimori's method of waveform recognition: A review and methodological considerations for its application to all-night sleep EEG. J. Neurosci. Meth. 64, 1-12
  • Uchida, S., Maloney, T., Feinberg I. (1994). Sigma (12-16 Hz) and beta (20-28 Hz) EEG discriminate NREM and REM sleep. Brain Res.659, 243-248.
  • Uchida, S., Atsumi, Y., Kojima T. (1994). Dynamic relationship between sleep spindles and delta waves during a NREM period. Brain Res. Bull. 33, 351-355.
  • Uchida, S., Maloney, T., Feinberg I. (1992). Beta (20-28 Hz) and Delta (0.3-3 Hz) oscillate reciprocally across NREM and REM sleep. Sleep. 15, 352-358.
  • Uchida, S., Maloney, T., March, J.D., Azari, R., Feinberg I. (1991). Sigma (12-15 Hz) and delta (0.3-3 Hz) EEG oscillate reciprocally within NREM sleep Brain Res. Bull. 27, 93-96.


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