|Budget Amount *help
¥3,300,000 (Direct Cost : ¥3,300,000)
Fiscal Year 1998 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1997 : ¥2,200,000 (Direct Cost : ¥2,200,000)
The procerebrum, a central olfactory organ of The terrestrial mollusc Limax marginatus, is clearly compartmentalized to a cell mass consisting of cell bodies of the local interneurons and neuropils where neurites of intrinsic and extrinsic neurons are interconnected. To clarify the mechanisms of odor information processing and odor-taste associative learning, responses of The procerebrum to olfactory input should be analyzed using an optical recording technique. For this purpose, it is most desirable to obtain signals only from the cell mass in its posterior view without interference by the signals from the underlying neuropils which contain those of neurites of extrinsic neurons as well. In the present study, fluorescent Ca^<2+> indicator dyes were used to stain selectively The cell mass for Their incorporation into cytoplasm of the cell soma, while potential-sensitive dyes were incorporated into the cell membranes to record predominantly electroactivities of the neuropils. A differential imaging system, which has a wide dynamic range virtually, well extracted signals of intracellular calcium from large background fluorescence which in general accompanied tissue-staining with acetoxymethyl esters of Ca^<2+> indicator dyes. Ca^<2+> signals conveying information on the neural activity of the CM exhibited synchronous oscillation, wave propagation, and responses to the excitation of the olfactory nerve. The present study indicates that optical recording with Ca^<2+> indicator dyes provides a useful means to selectively observe neural activities of The cell mass of the procerebrum.