Assessment of Cognitive and Sensorimotor Defi cits - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 236

almost nothing by the end of 30 min as they habituate to the
environment. Activity levels signifi cantly different than normal
(e.g., hyper- or hypoactive) may result from differences in anx-
iety (indicated by differences in the amount of time spent in
the center of the container vs. in the corners and number of
droppings) and/or the tendency to habituate (which may indi-
cate differences in learning/memory).

3.3. Day 3 (See Note 3):
Accelerating Rotarod

1. Procedure . If using a video camera to assist with offl ine scoring,
start the recording. Start and prepare the apparatus according
to the procedure for that particular machine. Grab the animal
by the base of the tail and gently swing it (nose fi rst) into the
lane and onto the spindle. Gently support the animal by hold-
ing its tail until it has a fi rm footing then release the tail.
Generally, we run three blocks (separated by ~30 min) of two
consecutive trials (each with a 60 s maximum trial length).
Block 1: trials 1 and 2—stationary

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Block 2: trials 3 and 4—constant speed of 5 RPM

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Block 3: trials 5 and 6—start at 5 RPM and accelerate by

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2 RPM every 5 s
2. Variables measured . Latency to fall.
3. Data interpretation . Performance on this test refl ects senso-
rimotor coordination and balance. Performance improvements
with each trial represent motor learning.

3.4. Day 4 (See Note 4):
Zero Maze

1. Procedure . Turn on the lights to brightly illuminate the open
halves of the maze. If using a video camera to assist with offl ine
scoring, start the recording. The animal is placed at the mid-
point of one of the open areas of the track and allowed to
explore for 5 min.
2. Variables measured . Percent time spent in the open area of the
track, number of head dips over the side, total distance moved,
percent time spent moving, movement velocity, number of
rearings, and number of feces droppings.
3. Data interpretation . Generally, normal animals will spend the
majority (~60-70%) of the time in the enclosed half. Anxious
animals will spend even more time in the enclosed half, whereas
animals with low levels of anxiety behaviors will explore the
brightly lit open half more than controls.

1. Forced swim

3.5. Day 5 (See Note 5):
Forced Swim (Rats) or
Tail Suspension (Mice)

Procedure . If using a video camera to assist with offl ine
scoring, start the recording. Gently place the rat into the
cylinder of water and start the stopwatch.

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