Table 3.

Study design of piglet articles with shaking solely in a transverse plane (often referred to as axial in the articles) [6–10]

Article	Objective	Animals	Trauma mechanism	Fixation	Outcome measures	Input dynamics
Raghupathi 2002 [6] Journal of Neurotrauma Traumatic Axonal Injury after Closed Head Injury in the Neonatal Pig	To better understand the mechanical environment associated with closed pediatric head injury, by animal models including salient features.	7 piglets + 1 control; 3-to-5-day-old; average weight: 2.0 kg (1.5–3.0, 3 unknown). Average brain weight: 35 g (33–38).	Anesthesia and ventilation. Rapid, inertial, non-impact, transverse head rotation 110° over 10–12 ms, centered in the cervical spine, with HYGE pneumatic actuator. Heads secured to padded snout clamp.	6–8 h anesthesia and ventilation before death. Heparin perfusion, in situ fixation with 10% formalin, followed by ex-situ fixation overnight.	Macroscopy and microscopy of brain, cerebrum, and brain stem with Nissl staining, NF68 and NF200 immunohistochemistry; ABC-histochemistry.	Angular velocity of 272 rad/s. Average PAV of 250 ± 10 rad/s.
Raghupathi 2004 [7] Journal of Neurotrauma Traumatic axonal injury is exacerbated following repetitive closed head injury in the neonatal pig	To evaluate the effect of reducing the loading conditions on the extent of regional traumatic axonal injury, and to develop a model of repeated mild brain trauma.	11 piglets + 3 controls; 3-to-5-day-old. Group 1 (n = 5): single rotation (15 ms), ± weight 2.0 kg (1.8–2.4), ± brain weight 36 g. Group 2 (n = 6): double rotation (15 ms, 10–15 m apart), ± weight 2.1 kg (1.7–2.5), and ± brain weight: 35 g.	Anesthesia and ventilation. Rapid, non-impact, transverse rotations of the head centered in the cervical spine, with HYGE pneumatic actuator. Heads secured to padded snout clamp.	6 h Anesthesia and ventilation before death. Heparin perfusion, in situ fixation with 10% formalin, followed by ex-situ fixation overnight.	Macroscopy and microscopy of brain, cerebrum, and brain stem with NF200 immunohistochemistry, and ABC-histochemistry.	PAV averaging 172 rad/s for single and 138 rad/s for double loads.
Friess 2007 [8] Experimental Neurology Neurobehavioral Functional Deficits Following Closed Head Injury in the Neonatal Pig	To develop reliable quantitative functional neurobehavioral assessments for brain injury in piglets.	18 piglets + 9 controls; 3-to-5-day-old. Group 1 (n = 10): 1 moderate acceleration (188 rad/s). Group 2 (n = 5): controls moderate group. Group 3 (n = 8): 2 consecutive transverse, mild accelerated (142 rad/s) head rotations, 3.1 ± 0.5 min apart. Group 4 (n = 4): controls mild group.	Anesthesia and ventilation. Single, rapid, non-impact, transverse head rotation with the HYGE pneumatic actuator, 1–3 min after end of isoflurane. Heads secured to padded bite plate.	After 12 days re-anesthetized, death by pentobarbital, heparin and then in situ fixed with 10% formalin. Ex situ fixed overnight.	Macroscopy and microscopy of brain, cerebrum, brain stem, and high cervical spinal cord with HE staining, β-APP staining, and NF68 immunohistochemistry and counterstained with Meyer’s hematoxylin.	Moderate acceleration: 62.90 ± 10.10 krad/s2, velocity: 188 ± 7 rad/s. Mild acceleration: 34.12 ± 2.80 krad/s2, velocity: 142 ± 2 rad/s.
Friess 2009 [9] Journal of Neurotrauma Repeated traumatic brain injury affects composite cognitive function in piglets	To develop a cognitive composite dysfunction score to correlate white matter injury severity in piglets with neurobehavioral assessments.	21 piglets + 7 controls (7 littermate groups, of 5 piglets); 3-to-5-day-old. Group 1 (n = 7): single. Group 2 (n = 7): double; 1 day apart. Group 3 (n = 7): double; 7 days apart. Group 4 (n = 7): controls. Group 5 (n = 5): controls for group 3	Anesthesia and ventilation. Moderate (190 rad/s) rapid, non-impact, transverse angle rotation of 110° over 10–12 ms with HYGE pneumatic actuator. Heads secured to padded bite plate.	After 12 days re-anesthetised, death by pentobarbital/heparin, then in situ fixed with 10% formalin. Ex situ fixed overnight. Group 3 and 5 sacrificed after 5 days instead of 12.	Macroscopy and microscopy of brain, cerebrum, brain stem, and high cervical spinal cord with HE staining, β-APP staining, and counterstained with Meyer’s hematoxylin.	Velocity: Gr 1:: 193.7 rad/s, Gr 2: 196.7–195.9 rad/s, Gr 3:: 190.3–187.6 rad/s Acceleration: Gr 1: 58.51 krad/s2. Gr 2: 55.17–54.35 krad/s2. Gr 3: 57.32–56.12 krad/s2
Naim 2010 [10] Developmental Neuroscience Folic Acid Enhances Early Functional Recovery in a Piglet Model of Pediatric Head Injury	To test if folic acid supplementation after injury would decrease the severity of TAI in our well-established piglet model of moderate pediatric head injury.	4 groups: 40 female + 10 male piglets, 3-to-5-day-old. Group 1 (n = 7): injured + daily intraperitoneal folic acid injection (IF) 2.24 kg. Group 2 (n = 8): injured + daily saline injection (IS) 2.01 kg. Group 3 (n = 8): uninjured + daily folic acid injection (UF) 1.8 kg. Group 4 (n = 7): uninjured + daily saline injection (US) 1.99 kg. Group 5: behavior controls.	Anesthesia and ventilation. Rapid, inertial, 90–110° transverse rotation, centered in the cervical spine with the HYGE pneumatic actuator. Heads secured to padded bite plate.	After 6 days re-anesthetized, death by pentobarbital, heparin and then in situ fixed with 10% formalin.	Behavioral testing on days 1 and 4 following injury. Macroscopy and microscopy of brain, cerebrum, brain stem, and high cervical spinal cord with HE staining, β-APP staining, and counterstained with Meyer’s hematoxylin.	Angular velocity: IF group: 193.29 ± 5.31 rad/s, IS group: 194.25 ± 8.11 rad/s

β-APP immunohistochemistry (β-amyloid precursor protein) HE-stain hematoxylin and eosin stain, NF Neurofilament ABC avidin-biotinperoxidase histochemistry, PAV peak angular velocity