September 22, 2008
Haifa Identifies Long-Term Memory Protein
By JUDY SIEGEL-ITZKOVICH
A protein essential in long-term memory consolidation has been identified at the University of Haifa. As the process of memory creation and consolidation is the first to be affected in neurodegenerative diseases like Alzheimer's and Parkinson's, understanding the biological mechanisms of the process brings us one step closer to finding a treatment for these diseases, said chief researcher Prof. Kobi Rosenblum, who published the study in the prestigious journal Nature Neuroscience.
The human brain constantly receives sensory stimuli from the outside world - sounds, tastes, visual images, touch and smells. A very small fraction of these stimuli recorded in short-term memory become part of our long-term memory. Previous studies in the university's laboratory for molecular mechanisms of learning and memory identified a protein linked to the quality of long-term memories. In the current study, researchers were looking to understand how long-term memories are stabilized.
Rosenblum, who heads the department of neurobiology and ethology, was assisted by doctoral student Alina Elkobi, Drs. Katya Belelovsky and Liza Barki, and worked in cooperation with Dr. Ingrid Ehrlich from the Friedrich Miescher Institute at the University of Basel. They searched for a protein present during the process of memory formation that is an essential factor in the process. Using taste learning in mice, the researchers found learning- related induction of the protein PSD-95 in the cortex "taste center" during the process of memory creation. However, when the mice were exposed to known tastes, PSD-95 was not induced in this center.
To prove that PSD-95 is essential for the process of memory creation, the researchers used two different groups of mice that had undergone the same tests for taste learning. Using genetic engineering, the researchers halted the process of PSD-95 production in the nerve cells of the taste center in the cortex. The group whose PSD-95 production was stopped had no memory of new tastes the day after being introduced to them, while the other group remembered the tastes, thus demonstrating that a new memory was created when PSD-95 was induced, and that the information disappeared when the protein was not induced. The study further examined the effect of PSD-95 on existing memories. Mice that had already been introduced to and remembered certain tastes were genetically engineered to stop producing the protein and they still remembered the tastes, which showed that while PSD-95 induction is essential for memory creation, its absence does not affect memory retention.
The process of long-term memory creation in the human brain is one of the incredible processes so clearly different than found in "artificial brains" like a computer. While an artificial brain absorbs information and immediately saves it in memory, the human brain continues to process information long after it is received, and the quality of memories depends on how the information is processed.
"One of the first processes to be affected in neurodegenerative diseases like Alzheimer's and Parkinson's is that of memory acquisition and processing. In this research we identified one specific protein, among the many active in brain synapses whose production is essential to process and remember information it receives. The more we understand about the processes and elements involved in this complicated process, the sooner we will be able to develop medications which will delay the progress of cognitive degenerative diseases and enable patients to continue normative functioning," explains Rosenblum.
SKIN PATCH TRIAL FOR OSTEOPOROSIS
Teriparatide (Forteo) is a drug with a potential to treat severe osteoporosis. But it isn't in the basket of health services and thus costs NIS 3,000 - and it has to be injected. But Prof. Yosef Foldes, head of the Hadassah Osteoporosis Center on Mount Scopus in Jerusalem, is now testing the drug with daily skin patches after an Israeli- made device opens the pores to improve entry of the molecules.
"We are currently recruiting women for a new three- month Phase II clinical trial aimed at examining the possibility of delivering the drug by transdermal patches rather than by injection," Foldes said. Half of the participants, who must live in the Jerusalem area and undergo periodic blood tests, will get the patches and the rest will get injections. The researchers want to know if patches make the drug as easily absorbed as when injected. Potential participants must be 55 and over, at least three years postmenopausal, and taking no medications for osteoporosis. Call (02) 584-5099/095 or fax details to (02) 584-5050.
Originally published by JUDY SIEGEL-ITZKOVICH.
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