From: John Clark (jonkc@worldnet.att.net)
Date: Mon Sep 06 1999 - 09:47:24 MDT
If the words "mouse intelligence" has any meaning at all then these are the
reasons Dr. Tang is justified in saying that Doogie is smarter than wild mice.
Test #1) The mice were placed in a conditioning box, they heard a tone and then
were shocked a short time later. The Doogie mice learned much faster and
remembered longer to express a fear response as soon as they were placed in the
box. This is called contextual specific learning and is known to be largely dependent
on one the hippocampus.
Test #2) The mice also learned to express fear as soon as they heard the tone.
This may seem similar but it's called cued fear learning and has been shown to
work with a completely different mechanism that has nothing to do with the
hippocampus. The Doogie did much better here too.
Test #3 and #4) After conditioning the two above experiments were repeated but
this time the shock was not given and the time it took for fear extinction was recorded.
Again Doogie easily beat the wild mice in both cases.
Test #5) In a training period of 5 minutes two objects were placed in the mouse cage,
both mice spent an equal amount of time exploring both objects. One hour later one
novel object and one of the old objects were placed in the cage, both mice spent
much more time exploring the novel object indicating that Doogie's short term
memory was no better than the wild mice. However when the experiment was
repeated 3 days later Doogie spent much more time on the novel object indicating
better long term memory that the wild mouse. The article says that this novel object
recognition ability is " evolutionarily conserved in species including humans and
rodents and requires the hippocampus".
Test #6) This was the standard hidden platform water maze to determine spatial
learning ability, and Doogie's superiority over the control was "significant".
Spatial visualization is involve with NMDA receptors in the hippocampus.
These are thought to be 6 different abilities, 4 involved the hippocampus and
2 did no. Doogie did consistently better on all of them.
John K Clark jonkc@att.net
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