Lactic Acid May Help Crucial Brain Functions

By Jane Farrell

Researchers have uncovered a previously unknown mechanism in the body that regulates a hormone that is essential for a number of crucial functions, including the control of blood pressure.

The discovery, by investigators from the University of Bristol, in the UK, and University College London, found that lactate (lactic acid) causes cells in the brain to release the hormone norepinephrine. Besides controlling blood pressure, norepinephrine is essential for motivation, stress responses and control of pain and appetite. Without norepinephrine, people have difficulty waking up and focusing.

The scientists’ discovery could help to design drugs to help fight health problems connected with these functions.

Lactate was first discovered in sour milk by a Swedish chemist, Carl Wilhelm Scheele in 1780. It is produced naturally by the body, for example, when muscles are at work. Regarded as a natural energy source, lactate can be delivered to neurons as fuel to keep them going.

 But this latest research discovered another function for lactate as a signal between brain cells. And that finding implies there is a still unknown receptor in the brain for lactate that is needed for the substance to work.

Dr Anja Teschemacher, also from the University of Bristol, added: "The next big task is to identify the receptor…If we can regulate the release of noradrenaline – which is absolutely fundamental for brain function – then this could have important implications for the treatment of major health problems such as stress, blood pressure, pain and depression."