A research team led by Dr. Xiang Wang and Professor Hans-Hermann Gerdes at the University of Bergen’s Department of Biomedicine found that cells in the human body communicated through electrical signals emitted through nanotubes at high speed.
The on-going research program is being carried out under the aegis of the Research Council’s large-scale Nanotechnology and New Materials (NANOMAT).
The team used fluorescent dye because this changes the concentration in tune with the changes in the electric element of the cell membrane. A nanotube connects two cells. Dr Wang prodded one of them using a microinjection needle in an endeavor to depolarize its membrane potential. This resulted in the fluorescent tag being illuminated. This illumination was followed by a similar one in the connected cell.
The team measured the conductivity of the cell systems to record the electrical coupling power. The research paper was released in “Proceedings of the National Academy of Sciences” (PNAS) and highlighted in Nature News. Most intercellular nanotubes exist only for a few minutes. This made it difficult to determine where and when nanotubes would form.
The team created a micro-matrix comprising multitudes of points and bridges on a plate surface in an effort to detect nanotubes easily. A nano –material was used to cover the nano-sized plate. The cells attached to the material. A single cell was placed on each nano-point. The camera was then focused on to the bridges between the points in the hope of nanotubes will be established. The team identified the nanotubes and then prodded the cells at periodic intervals, programming the microscope to capture about 50 target points once in five minutes. Images of multiple of nanotube connections were thus captured.
Dr. Wang found that a nanotube on its own could not transmit signals. Multiple cells form nano-pores on the membrane called gap junctions comprising ring-shaped proteins. One nanotube end was found to constantly stay connected to the cells via a gap junction before emitting electrical impulses.
Voltage-gated calcium channels in some connected cells were discovered to relay the incoming signals. Once the electrical signal reached the membrane of the cell at the receiving end, the surface of the membrane became depolarized. This opened the calcium channel and allowed calcium to enter.
According to Professor Gerdes, a nanotube grows from one cell and connects to another through a gap junction. This allows the cells to be connected electrically.
Source: http://www.forskningsradet.no/