Cellular 'heartbeat' to revolutionise drug testing

Researchers are a step closer to being able to detect what they have called the ‘heartbeat’ of individual cells, in a development that could change the way new drugs are tested.

Detecting the usual pattern of electrical activity in a yeast cell could allow scientists to detect the effect of drugs

Most biological cells have a system of ion transfer across their membranes and it is this current that researchers from the University of Manchester are hoping to detect.

The recognition of such electrical activity would provide a kind of ‘cellular cardiogram’ allowing the daily functioning of the cell to be monitored in a similar way to a cardiograph showing the workings of a human heart.

“Once we know the average or usual pattern of electrical activity in a cell, we can see how different drugs affect it,” said Professor Andre Geim, leader of the research team.

Their initial attempts at detection – based on modified apparatus used originally to detect magnetic fields in superconductors – failed to pick up the cellular current of their model organism – a yeast cell. However, it was the addition of a Russian tipple that was to be their breakthrough.

“We added ethanol – which is essentially vodka – to provoke a response from the cell. Ethanol is known to increase the transparency of cellular membranes which we hoped would give a signal we could detect,” said Dr Irina Barbolina, who carried out the experiments.

As soon as the yeast got a taste of the vodka, the probe registered an electrical signal. “It was probably the last gasp of the dying cell,” said Professor Geim.

Although not the cardiogram they had hoped for, the electrical signal was the smallest yet detected from a living cell, around 100 times smaller than anything previously detected. It added up to an electrical current of just 10 moving electrons.

The team are hopeful that they can develop their techniques to allow the detection of ‘cellular cardiograms’ for use in early drug trials. This, they hope, would put an early safeguard into the drug testing system that could be applied long before the drug was tested on animals or even humans. In addition, the electrical activity test could be used to monitor the effects of pollution on naturally occurring micro-organisms in the environment.