USC Scientists Identify Enzyme Important In Short-term Memory

November 11, 1998

An enzyme that fails to get activated in patients with Alzheimer's disease may play a broader role in normal memory, report USC neuroscientists Zoltan Tokes, Ph.D., and Giselle Lim, Ph.D., at the meeting of the Society for Neuroscience in Los Angeles today.

In 1996, Tokes showed that an enzyme produced by neurons in the hippocampus, a region of the brain important in short term memory and learning, was inactive in Alzheimer's patients.

The inactivity of the enzyme persisted despite a greater amount of the enzyme, called matrix metalloproteinase-9 or MMP-9, being produced in the neurons of people with Alzheimer's. In healthy brains, investigators believe MMP-9 acts to help digest and clear away proteins that may accumulate around the nerve cells and interfere with their function.

The team hypothesized that the inactive MMP-9 found in Alzheimer's patients might explain the build-up of characteristic protein plaques found in these patients. Now, Tokes and colleagues say that the inactivated enzyme might also explain the loss of memory seen in Alzheimer's patients.

Tokes' collaborators, cancer researchers Zena Werb and Tienna Vu at U.C. San Francisco, created a transgenic mouse that was missing a gene for the MMP-9 enzyme. Using a standard memory assay, Tokes and Lim then showed that the "knockout" mice had impaired memory. The finding supports the USC team's idea that inactivity of the MMP-9 enzyme may contribute to the memory impairment seen in patients with Alzheimer's.

University of Southern California

Related Neurons Articles from Brightsurf:

Paying attention to the neurons behind our alertness
The neurons of layer 6 - the deepest layer of the cortex - were examined by researchers from the Okinawa Institute of Science and Technology Graduate University to uncover how they react to sensory stimulation in different behavioral states.

Trying to listen to the signal from neurons
Toyohashi University of Technology has developed a coaxial cable-inspired needle-electrode.

A mechanical way to stimulate neurons
Magnetic nanodiscs can be activated by an external magnetic field, providing a research tool for studying neural responses.

Extraordinary regeneration of neurons in zebrafish
Biologists from the University of Bayreuth have discovered a uniquely rapid form of regeneration in injured neurons and their function in the central nervous system of zebrafish.

Dopamine neurons mull over your options
Researchers at the University of Tsukuba have found that dopamine neurons in the brain can represent the decision-making process when making economic choices.

Neurons thrive even when malnourished
When animal, insect or human embryos grow in a malnourished environment, their developing nervous systems get first pick of any available nutrients so that new neurons can be made.

The first 3D map of the heart's neurons
An interdisciplinary research team establishes a new technological pipeline to build a 3D map of the neurons in the heart, revealing foundational insight into their role in heart attacks and other cardiac conditions.

Mapping the neurons of the rat heart in 3D
A team of researchers has developed a virtual 3D heart, digitally showcasing the heart's unique network of neurons for the first time.

How to put neurons into cages
Football-shaped microscale cages have been created using special laser technologies.

A molecule that directs neurons
A research team coordinated by the University of Trento studied a mass of brain cells, the habenula, linked to disorders like autism, schizophrenia and depression.

Read More: Neurons News and Neurons Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to