|Budget Amount *help
¥6,100,000 (Direct Cost : ¥6,100,000)
Fiscal Year 1994 : ¥1,600,000 (Direct Cost : ¥1,600,000)
Fiscal Year 1993 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1992 : ¥2,700,000 (Direct Cost : ¥2,700,000)
It is known that a neural cell elongates neurites and make a synaptic combination with a target cell. In a process of this neurite growth, some intercellular interaction might be worked between neurons. In order to analyze this intercellular interaction, the present research project was done from 1992 to 1994.
In 1992, using the cultured nerve cells PC12h-R,we developed lone cell culture system which excluded the intercellular interaction absolutely because only one cell was cultivated in a culture well. The usefulness of this system for further research work was shown.
In 1993, a neurite growth initiating activity of various factors (neurotrophic factors, neurotransmitter, hormone, second messenger) was evaluated by using lone cell system. Moreover, a flow culture system which could change the kind and concentration of working factors continuously and satisfied the lone cell culture condition was developed.
In 1994, we analyzed the chemical and physical factors of intercellular interaction by using the developed culture systems. As a chemical factor, some protein, whose molecular weight was 130-170kDa and which induced the neurite growth, was found in the supernatant of the conditioned medium of PC12h-R.It was shown that the stimulation by an alternating current (intensity : >2 muA) also induced the neurite growth. Moreover, in PC12h-R cells, the response of neurites to the repeated actions of NGF or db-cAMP whose action mechanisms were different to neural cells was analyzed.
These results were new knowledge and could be obtained by using our developed culture system. It was concluded that both chemical and physical factors were complicatedly related to the intercellular interaction in the process of the neurite growth.