Who hasn't reminisced about their first bicycle or a visit to the zoo during childhood? These cherished memories often remain vivid throughout our lives. But how does our brain manage to preserve these moments with such fidelity?
A study published in the journal
Science Advances has unraveled this mystery by identifying a key ingredient: the KIBRA molecule. A team of researchers discovered that this molecule acts as "glue" in our brains, helping to keep our memories intact.
Memories are stored by the interaction of two proteins: a structural protein, KIBRA (green), which acts as a persistent synaptic tag, and a synapse-strengthening enzyme, the protein kinase Mzeta (red).
Drugs that disrupt the interaction that perpetuates memory (other colors) erase long-term memories and pre-established old memories.
Credit: Changchi Hsieh, Ph.D. An international team of researchers highlighted the role of the KIBRA protein (short for “kidney and brain expressed protein”) in forming and maintaining long-term memories. You can think of KIBRA as a special glue that helps hold together the essential molecules for memory creation.
According to André Fenton, professor of neuroscience at New York University and one of the primary researchers of the study, "
our study shows how these molecules work together to ensure the perpetual storage of memory."
The memory storage process
To grasp the significance of this discovery, it's useful to briefly recap how our brain stores memories. Our brains are composed of billions of neurons that communicate with each other through connections called synapses. When a memory forms, certain synapses are strengthened while others remain weak. This network of strong and weak connections forms the basis of the memory.
However, the molecules in our synapses are in constant motion, continually wearing out and renewing themselves. How, then, do our memories remain stable for years, even decades? This is where KIBRA comes into play.
By studying laboratory mice, the researchers found how KIBRA interacts with another key memory molecule, called PKMzeta. This latter molecule is essential for strengthening synapses in mammals, but tends to degrade quickly.
A persistent synaptic tagging mechanism
During memory formation, involved synapses are activated, and KIBRA is selectively positioned in these synapses. PKMzeta then binds to the synaptic tag KIBRA and maintains these synapses strong.
This process allows synapses to remain stable and continue attracting new PKMzeta molecules, thereby ensuring the stability of memories.
Understanding how our brain maintains memories stable over long periods could pave the way for new treatments for conditions like Alzheimer's disease or post-traumatic stress disorder (PTSD).
By delving deeper into these mechanisms, the researchers hope to develop strategies to enhance or restore memory in individuals with neurological and psychiatric disorders.
Article author: Cédric DEPOND