How neurons encode memory remains one of the current challenges of neuroscience. The cerebellum represents a valuable model area to investigate this, for instance because of its simple and modular structural organization and for the direct control of simple motor outputs. It is known that a combination of phenomena occurring at different sites of the circuit can contribute to encode memory. These are several forms of “activity-dependent plasticity” (i.e. changes in properties of neurons that are caused by their activity, representing a trace of previous events and experiences). Understanding these mechanisms and how they are altered in pathological conditions allows identifying and designing better intervention strategies to restore brain functions in brain diseases.
Specifically in this project we have investigated the role of one of the only two inputs of the cerebellum, known as “climbing fiber”. It is well known that it plays a crucial role in “instructing” the cerebellum on motor errors, and, by doing this, it fine-tunes the circuit. It has been, however, unknown whether this kind of fibers can significantly change their morphology based on their activity as other fibers can do in other brain areas, and whether this could contribute to encode memories. We have studied this possibility finding that they are actually able to change their structure based on their activity and we have provided first evidence suggesting that this may potentially affect the function of the circuit and that, therefore, this mechanism may contribute to encode memories. This is adding a new element in the complex group of mechanisms that allows the cerebellum to encode and store memories and the basis for a better understating of brain function and dysfunction.
