NATIONAL QUALIFICATIONS CURRICULUM SUPPORT
Human Biology
Unit 3: Neurobiology and
Communication
A Case Study into ExperienceDriven Plasticity in the Brain
Teacher’s Notes
[HIGHER]
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Acknowledgement
Learning and Teaching Scotland gratefully acknowledges this contribution to the National
Qualifications support programme for Human Biology.
© Learning and Teaching Scotland 2011
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A CASE STUDY INTO EXPERIENCE DRIVEN PLASTICITY IN THE BRAIN (H, HUMAN BIOLOGY)
© Learning and Teaching Scotland 2011
Contents
Teacher’s notes
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Answers to activities
Activity 1
Activity 2
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A CASE STUDY INTO EXPERIENCE-DRIVEN PLASTICITY IN THE BRAIN (H, HUMAN BIOLOGY)
© Learning and Teaching Scotland 2011
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TEACHER’S NOTES
Teacher’s notes
This case study aims to reinforce the concept of neuronal plasticity by
discussing environmental enrichment and sensory deprivation as experimental
strategies.
The case study is split into four sections:
1.
Some background on neuronal plasticity
2.
Environmental enrichment and Activity 1
3.
Sensory deprivation and Activity 2
4.
Critical period as a concept in developmental plasticity (no activity –
this is a short reading extension to aid understanding)
Both activities are based on interpreting basic scientific data from key
experiments in each field (environmental enrichment and sensory
deprivation). The methods and results for each activity are based on actual
experiments conducted by scientists in a laboratory. Although not too
technically challenging for students to interpret, the idea behind each activity
is to expose students to genuine scientific method whilst further developing
their analytical skills.
Students should read through the background material and methods section
for each activity before attempting to interpret the data. This will give them a
wider understanding of the topic and enable them to draw accurate and more
detailed conclusions.
Students could work in pairs or small groups to complete each activity. This
will allow them to discuss the methods and develop a better interpretation. No
formal assessment is necessary as the activities are about familiarising
students with actual scientific data to give them a broader understanding of
the topic. Students could discuss their answers with other pairs/groups
followed by a class discussion of the model answers led by the teacher.
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A CASE STUDY INTO EXPERIENCE DRIVEN PLASTICITY IN THE BRAIN (H, HUMAN BIOLOGY)
© Learning and Teaching Scotland 2011
TEACHER’S NOTES
Answers to activities
Activity 1: Interpreting experimental data relating to
environmental enrichment
Figure 1
Greater BrdU staining is observed in the enriched mice compared to the
control group. Environmental enrichment therefore increases the number of
cells (or neurons) in the hippocampus.
As an extension, students could quantify the data by counting and plotting the
number of black dots in Figure 1 (ie BrdU staining) for enriched and control
mice.
Using Excel, students should get something similar to the table and graph
below. Students should understand that it is good practice in research science
to put numbers to results (to quantify data) to help interpretation.
Group
Number of BrdU stained cells
Control
~20
Enriched
~35
Number of stained cells in the hippocampus for
control (1) and enriched (2) mice
Number of cells
40
30
20
10
0
1
2
Group
A CASE STUDY INTO EXPERIENCE-DRIVEN PLASTICITY IN THE BRAIN (H, HUMAN BIOLOGY)
© Learning and Teaching Scotland 2011
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TEACHER’S NOTES
Figure 2
There are two parts to describing this graph:
1.
The correlation between latency and days.
For both groups time taken to locate the submerged p latform generally
decreases with number of days. All mice have the ability to learn the location
of the platform.
2.
The better performance of the enriched group.
Enriched mice were faster at locating the platform compared to controls in all
but one trial (trial 6 being the exception where performance was the same for
both groups). Environmental enrichment therefore improves learning
performance.
Activity 2: Interpreting experimental data relating to sensory
deprivation
Figure 1
Students should recognise and understand that monocular deprivation
produces a shift in the ocular dominance of cells in the visual cortex, and that
this is a result of experience-driven changes in plasticity.
For the normal, non-deprived mouse (Figure 1, left) the ocular dominance of
cells in the visual cortex was biased towards the opposite eye. A greater
proportion of cells on the right side of the brain (location of recordings)
responded more strongly to light presented to the left eye – over 40% of cells
were assigned a score of 2.
After 4 days of deprivation (Figure 1, right) this distribution shifts towards
the open, same-side eye. Cells on the right side of the brain (location of
recordings) were responding less to light presented to the left (deprived) eye
and more to light presented to the right (same -side) eye – more cells were
assigned scores of 5, 6 and 7. There was also a greater number of cells
responding equally to stimuli presented to both eyes as the proportion of cells
assigned a score of 4 is larger.
After 4 days of deprivation, the right side of the visual cortex demonstrates a
preference towards visual input from the open eye despite it being on the
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A CASE STUDY INTO EXPERIENCE DRIVEN PLASTICITY IN THE BRAIN (H, HUMAN BIOLOGY)
© Learning and Teaching Scotland 2011
TEACHER’S NOTES
same side of the brain. During normal visual development, the left side of the
brain dominates sensory information coming from the right eye and vice
versa.
Duration of the entire case study: 30–40 minutes
A CASE STUDY INTO EXPERIENCE-DRIVEN PLASTICITY IN THE BRAIN (H, HUMAN BIOLOGY)
© Learning and Teaching Scotland 2011
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