Thaindian News

London, April 25 (ANI): A new study has shed light on the molecular workings of transporter proteins, molecular machines embedded in the cell membranes of neurons that modulate the transfer of signals between cells and recycle neurotransmitters.

The finding by scientists from Columbia University College of Physicians and Surgeons and Weill Cornell Medical College reveals with unprecedented detail how the molecule performs its task.

“This level of understanding may ultimately lead to improved treatments for psychiatric disorders and increase our understanding of how drugs such as cocaine work,” said one of the senior authors Jonathan Javitch, the Lieber Professor of Experimental Therapeutics in Psychiatry and professor of pharmacology in the Center for Molecular Recognition at Columbia University Medical Center.

In the brain, one neuron communicates to another by releasing chemicals called neurotransmitters into the gap between them, called the synapse.

To stop the signal, specialized transporters must remove the released neurotransmitter from the synapse by pumping it back into the releasing cell. In the treatment of some diseases it is beneficial, however, to allow the neurotransmitters to build up in the synapses.

Antidepressants make this possible by interfering with particular transporters, as do stimulant drugs like cocaine and amphetamines.

Neuronal cells have different transporters. One family of transporters, known as neurotransmitter/sodium symporters (NSSs) are specialized for the uptake of certain neurotransmitters, including dopamine, noradrenaline and serotonin.

They are named symporters because the transport process requires energy to concentrate neurotransmitter inside neurons — the energy required is provided by the imbalance of sodium ions across the cell membrane.

Thus, sodium ions flow down their concentration gradient into the neurons through the NSSs, thereby allowing neurotransmitters to move back into the cell where their concentration is higher than outside. But until now, exactly how these transporters function has been a mystery.

“The transporters themselves are of enormous interest both medically and specifically to the National Institute on Drug Abuse because, fundamentally, they are essential for signaling,” said one senior author Harel Weinstein, chairman and Maxwell M. Upson Professor of Physiology and Biophysics, and director of the Institute for Computational Biomedicine at Weill Cornell Medical College.

“The better we understand neuronal signaling, the better we understand brain function, disease and drug addiction,” he added.

The study is detailed in the journal Nature. (ANI)