Experimental Traumatic Spinal Cord Injury - Tissue-Protective Cytokines: Methods and Protocols - page 103

Incomplete Transection : Unilateral or dorsal hemisections are
performed with a No:11 scalpel blade under dissecting microscope.
Bleeding is controlled by using hemostatic materials (see Note 3).

Spinal Cord Contusion and
Compression Models (See
Note 4 )

Spinous processes of vertebrae above and below the injury site are
secured in clamps to reduce motion of the spinal column during the
impact. In mice, size of the laminectomy (approximately 1.5 mm in
diameter) was consistent between animals to allow room for the impac-
tor tip. Care was taken not to remove the lateral part of the vertebra at
the site of laminectomy to maintain vertebral column stability. The
lateral processes of Th8 and Th10 vertebrae were cleared of muscle to
allow for stabilization of the vertebral column using forceps.

New York University Impactor : In this weight-drop contusion
model ( 3 ), a 10-g rod is dropped from heights of 6.25, 12.5, 25,
and 50 mm onto the exposed dorsal surface of the spinal cord at
T9-T10, producing more severe neurologic injuries with increasing
height (see Note 5).

Ohio State University Impactor : It is a computer feedback-con-
trolled electromechanical impactor rather than a weight drop ( 4,
8-10 ). The impactor probe is slowly screwed down to the dural
surface which it contacts and displaces 30 m with a force of

approximately 3,000 dynes for providing a consistent starting point
from which to initiate the injury. Then, the device rapidly impacts
the cord for a predetermined amount of displacement typically in
the range of 0.8 - 1.1 mm for less than 10 ms and is held for 4 - 5 ms
before releasing in less than 10 ms. There is no bouncing of the
impactor back onto the cord, which is a potential source of variation
in a weight-drop paradigm (see Note 6).

μ

Clip Compression : A temporary aneurysm clip exerting a 53 × g clos-
ing force on the spinal cord is applied extradurally for 1 min (Fig. 3 ).
A probable hemorrhage can be controlled by using hemostatic
materials. The compressive force is applied to both the volar and
dorsal aspects of the cord, making it somewhat more representative
of the human injury (Fig. 4 ) (see Note 7).

1. Closure: The skin incision is closed in layers and the animals allowed
to recover fully from anesthesia and returned to their cages.

2. Since this intervention is an important trauma to the animals,
hydration with subcutaneous fluids may help them to survive.
Besides, manual drainage of urine twicely in a day is a life saving
maneuver for those animals prior to the establishment of reflex
bladder.

3.3 Measures
of Structural and
Functional Outcomes

Experimental interventions in animal spinal cord injury models
can be evaluated anatomically, biochemically, neurophysiologi-
cally, and/or functionally. Anatomic assessment involves the use