Scientists peer into real time brain cell activity

The team found that when activity in one neuron is suppressed, others respond with greater excitement.

Last Updated: May 31, 2011, 15:50 PM IST

Washington: Scientists, for the first time, peered into real time brain cell activity that underlay memory formation.

Researchers reproduced the brain`s complex electrical impulses onto models made of living brain cells that provide an unprecedented view of the neuron (nerve cell) activity behind memory formation.

The team fashioned ring-shaped networks of brain cells that were not only capable of transmitting an electrical impulse, but also remained in a state of persistent activity associated with memory formation, said Henry Zeringue, who led the study at Pittsburg University.

Magnetic resonance images have suggested that working memories are formed when the cortex, or outer layer of the brain, launches into extended electrical activity after the initial stimulus, explained Zeringue, a bioengineering professor in Pitt`s Swanson School of Engineering.

But the brain`s complex structure and the scaled down model of neural networks makes observing this activity in real time nearly impossible, he added, according to a Swanson statement.

The Pitts team, however, was able to generate and prolong this excited state in groups of 40 to 60 brain cells harvested from the hippocampus of rats -- the part of the brain associated with memory formation.

Zeringue and colleagues were able to sustain the resulting burst of network activity for up to what in neuronal time is 12 long seconds.

Compared to the natural duration of .25 seconds at most, the model`s 12 seconds permitted an extensive observation of how the neurons transmitted and held the electrical charge, Zeringue said.

Besides, researchers produced the networks on glass slides that allowed them to observe the cells` interplay. The work was conducted in Zeringue`s lab by Pitt`s bioengineering doctoral student Ashwin Vishwanathan, which was published in UK journal, Lab on a Chip.

Vishwanathan co-authored the paper with Zeringue and Guo-Qiang Bi, neurobiology professor in Pitt`s School of Medicine.

Unravelling the mechanics of this network communication is key to understanding the cellular and molecular basis of memory creation, Zeringue said.

The team also found that when activity in one neuron is suppressed, the others respond with greater excitement.

IANS