Electrophysiology and Morris Water Maze to Assess Hippocampal Function After Experimental Subarachnoid Hemorrhage - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 399

and further characterized in 1984 ( 21 ). It is widely accepted and is
extensively used to examine a variety of aspects of hippocampal
function, such as spatial memory, as well as many other aspects of
neurocognitive function ( 22 ).
The advantages of the MWM are that it allows for examining a
variety of performance and learning assessments without extensive
pretraining since animals are natural swimmers and learn the
water-escape tasks easily ( 21 ). In addition, previously used aversive
procedures, such as food deprivation, difference in water tempera-
ture, and electric shock techniques to motivate learning are not
required. Furthermore, the water provides a control for olfactory
cues, video tracking devices can specifi cally identify the motor or
learning defi cits by eliminating the non-mnemonic behaviors, such
as thigmotaxis, and relearning experiments can be performed by
changing the platform location ( 23 ). Disadvantages of the MWM
are the relatively high cost of apparatus, requirement for a large-
enough space and a quiet environment to conduct experiments.
In addition, immersion into water may cause endocrinological or
other stress effects which may interact with experimental manipu-
lations and results in uncontrolled ways.

Large circular pool made of plastic and painted black (e.g., diameter:
180 cm, height: 76 cm for rats and diameter: 120 cm, height:
76 cm for mice).
Water to fi ll the pool.
Powdered milk or nontoxic paint to opaque the water (if needed).
Highly refl ective paint
A clear plexiglass platform (10 × 10 cm)
Unique geometric images made of cardboard.
Flag made of plastic tube and tape.
Black curtains
Video camera
Stopwatch
Automatic tracking system (Poly Track System, San Diego
Instruments, San Diego, CA).

4.1. Materials
and Instruments

4.2. Preparation
of Water Maze

All behavioral tests should be performed at the same time of the day.
Circular pool is fi lled with water to a depth of 40 cm at room tem-
perature (26 +/− 1°C).

Four equally spaced points around the circumference of the pool
are arbitrarily designated North (N), South (S), East (E), and
West (W), and thus four quadrants are established (NW, SW,
NE, and SE), and eight locations all together.
The area between an arbitrary inner circle (20 cm from the wall)
and the pool wall is designated as the wall area @ defi ning
thigmotaxis.