Electrophysiology and Morris Water Maze to Assess Hippocampal Function After Experimental Subarachnoid Hemorrhage - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 398

2.4. Data Analysis

Use clampfi t 9.2 to quantify the slope of the rising phase of the
EPSP and the amplitude of population spike.
Normalize all the data to baseline which is set as zero.
Compare the mean of post-HFS response at different time
points among the groups to look for signifi cant differences in the
degree of potentiation between the groups.
Assess the mean response induced immediately after HFS to
compare the induction phase of LTP between groups.
Statistical tests, such as one-way analysis of variance or
Student's t -test can be used.

3. Variations
in Electro-
physiological
Recording

Different protocols might be used to induce LTP. For instance,
HFS consisting of 5 trains of 20 shocks at 100 Hz with ITI of 6 s
( 17 ) and a tetanic volley of 100 Hz in 1 s have been used ( 18 ).

3.1. Variation in HFS

3.2. When to Perform
Electrophysiology
After SAH

LTP after experimental SAH can be examined at different time
points after experimental SAH.

3.3. Alternative
Methods to Examine
Hippocampal Function

Using fi eld potential recording, short-term plasticity of hippocam-
pal synapses could be examined. The most typical short-term plas-
ticity method is pair-pulse facilitation at the CA3-CA1 pathway in
which a pair of identical pulse stimulation with inter-pulse interval
of 50 ms is applied by the stimulating electrode. The potentiation
of the second response over the fi rst one would mean enhanced
short-term plasticity.
Whole cell patch clamp technique is another alternative method
to obtain specifi c information about hippocampal cell function by
studying the ion channels and associated receptors, as well as the
other components of the cellular machinery that control cell func-
tion. This method is more technically demanding. Field potential
recordings are simpler, easier to learn and set up, the equipment is
less costly but they provide a relatively general overall assessment
of populations of cells in the recorded regions.

4. Assessment
of Hippocampal
Function by
Behavior Testing
Using Morris
Water Maze

Many procedures have been developed that use escape from
water to stimulate learning and memory in animals ( 19, 20 ). Water
maze tasks have been quite useful in evaluating the effects of exper-
imental lesions and drug effects in rodents by measuring spatial
learning. The Morris water maze (MWM) was developed in 1981