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Department of Oral Physiology

Department of Neuroscience and Oral Physiology

The trigeminal nervous system, which controls sensory and motor functions in the oral and maxillofacial regions, has many unique features distinct from the other cranial and spinal nervous systems. We perform researches to elucidate the brain and neural mechanisms underlying the oral and maxillofacial functions, at various levels from molecules or cells to whole animals or human subjects by using electrophysiological, optical recording and molecular biological methods.


E-mail (below@, dent.osaka-u.ac.jp)
Takafumi Kato
Associate Professor
Hiroki Toyoda
Assistant Professor
Hajime Sato
Assistant Professor
Ayano Katagiri

Current Research Projects

1) Molecular basis and neural mechanism for the rank-order recruitment of masseter motoneurons
TASK1/3 channels are key determinants of input resistance. Since TASK1/3 channels are strongly expressed in masseter motoneurons, it is suggested that TASK1/3 channels are key molecules involved in the rank-order recruitment. Toward a comprehensive understanding of the isometric contraction during clenching, we investigate the roles of TASK1/3 channels in rank-order recruitment by using HEK cell expression system and brain slice preparation.

2) Functional roles of the primary sensory neurons of the mesencephalic trigeminal nucleus (MTN) in switching between the two types of jaw movements involved in clenching and vocalization
Clenching is a powerful isometric movement, while vocalization is not powerful but involves much larger and multiple translocations of jaw position, indicating that neural controls of the two jaw movements are quite different. We hypothesized that MTN neurons play key roles in switching between clenching and vocalization. This possibility is investigated by monitoring the firing activity of MTN neurons in freely moving animals and by performing whole-cell patchclamp recordings from MTN neurons in slice preparations of brainstem.

3) Functional interaction between the taste and autonomic areas in the insular cortex
We examine the effects of TRPV1 activation on the functional interaction between the taste area and the autonomic areas involved in respiratory, cardiovascular and visceral functions in the insular cortex by using patch-clamp recording and voltage-sensitive dye imaging techniques. The study will illustrate the neural mechanisms underlying the physiological responses induced by tasting and/or ingesting spices containing capsaicin.

4) Neural mechanisms underlying intra- and inter-columnar integration in the barrel cortex
How functional columns are synchronized or desynchronized is a most essential question on the integration of functional columns. In comparison with the insular cortex, functional columns are more distinct in the barrel cortex as respective columns in the barrel cortex receive and process the sensory information from respective whiskers. We aim to clarify how functional columns are integrated in the barrel cortex by using dual whole-cell recording and voltage-sensitive dye imaging methods.

5) Neural mechanisms underlying motor learning of clenching movement in human subjects
In order to elucidate the network mechanisms underlying clenching movement and its motor learning, we perform the experiments on human subjects, in which the sensory information from periodontal mechanoreceptors and/or muscle spindles in masseter muscles is blocked or modulated.

Current Research Projects