THE VARIED ROLES OF SNAILS - National Universities Commission

memory loss have a devastating consequence of long term
impaired memory and it occurs in millions of people. Using
materials from snails, scientists are putting together
information that will help in understanding and ultimately
preventing and treating memory disorders. They are
looking for brain molecules that are crucial for the building
up and maintenance of long term memory and learning.
People are now attempting to enhance, by chemical
activation or inhibit those functions in the common pond
snails.
Snails are ideal for this kind of study because humans and
pond snails actually share some important characteristics
unchanged by evolutions. These include the basic
molecular mechanisms that control long term memory and
learning. These processes involve the activation or
suppression of a protein CREB which is a key to the
formation of long term memory and are found in species
ranging from molluscs, flies, rats to man. These responses
can be tested by classical Pavlovian experiments that bring
about a conditioned response. It has been reported that a
snail exposed to the smell of pear drops and other foods
will respond weeks later to the smell of pear drops by
rhythmically moving its mouth parts in anticipation of
food, even when none is provided. This shows that the snail
now has a memory associating the smell of pear drops with
the arrival of food – a learned and remembered response.
This “flash bulb” response as it is called, created by just
one response to a stimulus is complemented by another test
where the snail is exposed to a tickling stimulus before
food is introduced. It takes very long for the snail to
associate this tickling with the arrival of food. Snail have
large neurones which are easily identified, manipulated and
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