Memory plays a crucial role in shaping our identity, not only for humans but also for other animals. Therefore, it is not surprising that many researchers consider the process of memory storage in the brain as one of the fundamental issues in neurobiology.
In the early 1970s, a significant discovery was made in the form of long-term potential (LTP), which indicated that electrical stimulation of the synapse between two neurons could lead to a long-lasting increase in signal transmission efficiency. This phenomenon, known as “synaptic strength,” is believed to be closely linked to memory formation.
One specific molecule, PKMZETA (protein kinase Mzeta), emerged as a key player in the understanding of LTP. Studies from 2006 revealed that blocking PKMZETA in rats resulted in the erasure of place memories, suggesting its importance in memory retention. Subsequent research confirmed the crucial role of PKMZETA in various memory processes.
Despite initial findings, challenges arose with the short lifespan of PKMZETA and the mechanism by which it reaches synapses for memory storage. A recent study published in the journal Science Advances offers a solution to these issues by identifying the interaction between PKMZETA and another molecule called Kibra, which marks activated synapses during learning.
Experiments indicated that disrupting the interaction between these two molecules impacted LTP and spatial memory in mice, highlighting the essential role of their collaboration in memory retention. While both molecules have short lifespans, their interaction ensures the longevity of memory storage.
Previous studies in 2013 raised doubts about the exclusive role of PKMZETA in long-term memory formation, as mice lacking PKMZETA were still able to form lasting memories due to another protein, Pkciota/Lambda, stepping in to fulfill its functions. The latest research clarifies this confusion by demonstrating that blocking PKMZETA alone, but not PKCIOTA/LAMBDA, can erase memories, emphasizing the significance of PKMZETA in long-term memory storage.
Despite these advancements, the quest for identifying the ultimate “memory molecule” continues, with enzymes like camkii also being considered as potential candidates. Further studies are needed to unravel this mystery and shed light on the complex processes involved in memory formation and retention.