Laboratory of Interdisciplinary Biology (Neural Circuit Function)

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Associate Professor
Kimura, Kotaro
mail kokimura[at]bio.sci.osaka-u.ac.jp
Fields

Interdisciplinary Biology

Belong

Graduate School of Science

Location

Toyonaka

Research Theme

Our research focuses on the function of the nervous system of a model animal, the nematode Caenorhabditis elegans. There are a number of advantages to using the C. elegans nervous system for functional analyses, including the small size of the entire nervous system of the organism (only 302 neurons), the description of all neuronal connections, and its various types of behavioral plasticity. In addition, many sophisticated genetic and optical techniques are available to analyze and manipulate the animals' neural functions.

Enhancement of odor-avoidance regulated by dopamine signaling

Kimura KD et al., J. Neurosci., 2010

Plasticity in sensory responses is one of the fundamentals of neural function in animals. To develop an original behavioral paradigm for understanding the molecular and cellular basis of neural function of C. elegans, we investigated plasticity of odor avoidance of the animals. We found that C. elegans exhibited an enhancement of avoidance behavior to a repulsive odor 2-nonanone after preexposure to the odor, which may be beneficial for the animals by protecting them from further disturbance. In addition, genetic and pharmacological analyses revealed that the enhancement of 2-nonanone avoidance requires dopamine signaling via D2-like dopamine receptor DOP-3, which functions in a pair of RIC interneurons to regulate the enhancement. These results demonstrate a new genetic and pharmacological paradigm for non-associative enhancement of neural responses that is regulated by dopamine signaling.

Quantitative analysis of odor avoidance behavior

Because an animal's behavior reflects the total sum of neural activities in the nervous system, dissecting individual behavioral components should allow us to estimate the neural activities in the nervous system. We are quantitatively analyzing various components of the 2-nonanone avoidance behavior of C. elegans with a tracking system that we developed in the previous work (Kimura et al., J. Neurosci. 2010). Our results suggest the animals may use a novel strategy for the 2-noanone avoidance.

Optical monitoring and regulation of neuronal activities

To prove that a particular activity pattern of a neuron is the causal reason for a specific neuronal function, it is necessary to artificially mimic the activity pattern and determine if it causes the expected results. For this purpose, the recently developed technology called optogenetics (Zhang et al., Nat. Rev. Neurosci. 2007) is extremely useful. In addition to the calcium imaging system for monitoring neuronal acitivities in C. elegans as mentioned above, we are also setting up a system for optogenetic regulation of the animal’s behavior.

0Dopamine receptor expression

1Tracks of the worms

2Blue light for stimulation

Bibliography

Kawazoe Y, Yawo H, Kimura KD. A simple optogenetic system for behavioral analysis of freely moving small animals. Neuroscience Research 75 , 65 - 68 (2013)

Kimura KD*, Fujita K, Katsura I. (* Corresponding author) Enhancement of odor-avoidance regulated by dopamine signaling in Caenorhabditis elegans. The Journal of Neuroscience 30 , 16365 - 16375 (2010)

Kuhara A, Okumura M, Kimata T, Tanizawa Y, Takano R, Kimura KD, Inada H, Matsumoto K, Mori I. Temperature sensing by an olfactory neuron in a circuit controlling behavior of C. elegans. Science 320 , 803 - 8 (2008)

Kimura KD*, Miyawaki A, Matsumoto K, Mori I*. (* Corresponding authors) The C. elegans thermosensory neuron AFD responds to warming. Current Biology 14 , 1291 - 1 (2004)

Wolkow CA*, Kimura KD*, Lee MS, Ruvkun G. Regulation of C. elegans life-span by insulinlike signaling in the nervous system. Science 290 , 147 - 150 (2000)

Kimura KD*, Tissenbaum HA,* Liu Y, Ruvkun G. daf-2, an insulin receptor-like gene that regulates longevity and diapause in Caenorhabditis elegans. Science 277 , 942 - 946 (1997)

Contact

TEL:06-6850-6706 FAX:06-6850-6769

http://www.bio.sci.osaka-u.ac.jp/~kokimura/e/Top.html

http://www.bio.sci.osaka-u.ac.jp/~kokimura/e/Top.html