CogniFit's Science blog: Different Types Of Learning At A Molecular Level

Different Types Of Learning At A Molecular Level

A study conducted at the Montreal neurological institute and Hospital of McGill University has shown that training that occurs over time differs from training that takes place at short intervals and creates different types of memory.
Memory is very sensitive to not only the amount of training but also the pattern or frequency of training as well. It was found that training that was widely spaced generated long-term memory while intense training presented at short intervals generated short term memory.

It has been known from previous studies that learning is better when training is spread out but the McGill study showed differences at a the molecular level.

The researchers used a type of mollusk, called the Aplysi, which is used as a model of learning in different studies. When an enzyme called protein kinase C Apl II (PKC Apl II) is released, it is a sign that some kind of learning has occurred. The release of OKC Apl II is very different however when there is spaced training and massed training.

When the communication between neurons is strengthened (synaptic facilitation), learning has occurred in the mollusk Aplysia. This process is controlled by the release of a neurotransmitter called serotonin.

When there were 4-5 spaced applications of serotonin, long term changes in the strength of the junction between two neurons (synapse) occur. But in the study, this spaced application of serotonin lead to less activation of PKC Apl II. This leads to stronger connections between neurons and therefore increased learning and memory.

In contrast, if the serotonin is applied continuously, as would happen with intensive learning and training, it was found that there was greater activation of PKC Apl II, suggesting that when this enzyme is activated, it may block the mechanisms for creating long-term memory, while retaining mechanisms for short-term memory.

In short, the study showed that the enzyme PKC Apl II is regulated differently by the two types of applications of serotonin, massed and spaced, and that the difference in activation can explain some of the differences between spaced and massed learning.