Table 2.
Summary of experimental variables and anxiety and depression related behavior test outcomes in bTBI.
| Behavior test | Rodent used | Position of animal | Animal restrained | Gas used in blast tube | Blast pressure | Duration of deficits | References |
|---|---|---|---|---|---|---|---|
| Elevated Plus Maze (EPM) | ICR mice (30–40 g) | 7 m away from detonation source | No | 500 g TNT | 17.2 kPa Shockwave and reflected wave | No deficits observed at day 7 | (59) |
| SD rats (~300 g) | Transverse prone position across the mouth of the blast tube. | Yes, with chest protection | Compressed air | 20.6 ± 3 psi | No deficits at 9 days but deficits were observed 46 days post blast. | (56) | |
| SD rats | 39 and 17 cm outside shock tube opening, 40 and 20° lateral to shock tube axis, respectively | Yes | Helium | 100 and 450 kPa reflected peak overpressure | No deficits at 4 days or 30 days post impact | (46) | |
| Male SD rats (150–200 g) | 265 mm from the exploding wire with head facing impact | No | Exploding wire technique to generate small scale blast waves | 95 kPa for 0.189 ms | At days 38 and 62 post blast | (47) | |
| SD rats (225–250 g) | Supine position with the blast wave generator nozzle right above the animal's head. | Yes, chest shielded with 2 mm lead plate | Nitrogen | 80 Psi | Deficits at day 9 but no deficits at days 22 and 48 post blast. | (31) | |
| Male Wistar rats (408.3 ± 93 g) | Right side of the front cortex is aligned to the impact | Yes | A lithotripsy machine fired 5 shockwave pulses with 60 Hz frequency | ~50 MPa | Significant deficits post blast impact | (81) | |
| SD rats (289 ± 21 g) | 17 cm from the exit of the tube at an angle of 18° to shock tube axis with the sagittal plane of rat head perpendicular to the radial axis of shock tube. | Yes | Helium | 450 kPa for 0.4 ms | At 60 days but not at 30 days | (48) | |
| ICR mice (30–40 g) | 7 m from detonation source. Animals were placed ‘side on’ to the blast source. | No | 500g of TNT | 17.23 kPa | No deficits were observed on days 7 and 14 post blast | (60) | |
| SD rats (~300 g) | Transverse prone position across the mouth of the blast tube. | Yes, with chest protection and head exposed | Compressed air | 20.63 psi | At days 15 and 44 post blast but not on day 66. | (57) | |
| SD rats (245–265 g) | Transverse prone position across the mouth of the blast tube. | Yes, with chest protection and head exposed | Compressed air | 20.63 psi | Inconclusive | (82) | |
| Male and naturally cycling female C57BL/6J mice (7–9 weeks of age) | Prone position facing blast exposure | Yes | Compressed air | 15.74 Psi | At 6 days post blast in male mice. Female mice had deficits that did not reach significance. | (83) | |
| LE rats (250 g−350 g; 10 weeks of age) | Head facing the blast exposure | Yes | Compressed air | 74.5 kPa | At 30 weeks post blast | (65) | |
| SD rats (60–70 days) | 503 cm from the bursting membrane and 112 cm from the open end of the driven cylinder | Not mentioned | Helium | 14 Psi | At 5 weeks post blast. | (53) | |
| Staircase test | ICR Mice (25–30 g) | 4 and 7 m away from detonation source | No | 500 g TNT | Shockwave and reflected wave 2.5Psi or 5.5 Psi | Up to 30 days for both groups of animals | (12) |
| Elevated Zero Maze | Adult C57BL/6 mice (12–16 weeks) | 1 cm outside exit end of blast tube facing head front. | both head restrained and unrestrained | Helium | Mild blast of 215 ± 13 kPa, 46 ± 5 kPa * ms impulse or moderate blast of 415 ± 41 kPa, 148 ± 12 kPa * ms impulse | No significant deficits in both blast groups vs. sham 24 h post blast. | (66) |
| LE rats (250–350 g, 10 weeks old) | 30 cm inside the shock tube with head facing the blast exposure | Yes | Compressed air | 74.5 kPa for 3 days | At 24 weeks post blast. | (50) | |
| LE rats (250–350 g, 10–12 weeks old) | Head facing the shockwave exposure | Yes | Compressed air | One 74.5 kPa exposure for 3 consecutive days | At week 11 post blast. | (62) | |
| LE rats (250–350 g) | 18 inches inside the shock tube, both facing and sideways to the blast | Yes | Compressed air | 74.5 kPa for 3 days | 3 rats had deficits while 9 did not at 3 weeks post injury. 9 unaffected and 4 affected rats at 6-month timepoint. | (84) | |
| Open Field test (OFT) | Adult C57BL/6 mice (12–16 weeks) | 1 cm outside exit end of blast tube facing head front. | Both head restrained and unrestrained | Helium | Mild blast of 215 ± 13 kPa, 46 ± 5kPa * ms impulse or moderate blast of 415 ± 41 kPa, 148 ± 12 kPa * ms impulse | At day 4 post blast | (66) |
| C57BL/6J mice (2-month-old) | Prone position 3, 4, and 7 m away from the source with mice head longitudinally aligned to the shockwave propagation | No | C4 explosives | ~46.6 kPa, ~31.9 kPa and ~19.6 kPa corresponding to 3, 4, and 7 m distances from source. | At 6 days post injury in the 3 m blast group | (58) | |
| SD rats (215–300 g) | 73 cm inside the shock tube in an antero- posterior axis with head perpendicular to the shockwave | Yes | Compressed air | 3 blasts of 40 Psi; each blast was administered at an interval of 14 days | At days 1 and 7 post blast | (85) | |
| SD rats (300 g) | 19 cm from the nozzle opening at an angle of 21° from the vertical axis of the shock tube. | Not mentioned | Nitrogen gas | 28 kPa | At 3 days post impact | (86) | |
| SD rats (300–330 g) | Transverse prone position across the mouth of the blast tube. | Yes. Chest protection with rat head exposed | Compressed air | 138 kPa single or 5 blasts | Significant deficits on day 1. No deficits were observed on day 16 | (19) | |
| Male and naturally cycling female C57BL/6J mice (7–9 weeks of age) | Prone position facing blast exposure | Yes | Compressed air | 15.74 Psi | No deficits | (83) | |
| Male C57/Bl6 mice (3–4 months; 25.22 ± 1.96 g) | Supine position 53 cm from driven section opening | Yes | Helium | Rupture pressure of 183 kPa(mild) or 213 kPa (moderate) | Moderate blast rats had deficits up to 30 days. Mild injury rats had deficits up to 10 days. Freezing response was observed in mild rats up to 30 days. | (16) | |
| SD rats (325 g) | Prone position with the right side of the thorax facing the shock wave | Not mentioned | Helium | 28.49 ± 1.5 Psi in 2.475 ± 0.16 ms | Significant deficits 6-days post blast | (87) | |
| Forced Swim test | Male SD rats (150–200 g) | 265 mm from the exploding wire with head facing impact | No | Exploding wire technique to generate small scale blast waves | 95 kPa for 0.189 ms | No deficits were observed | (47) |
| Male SD rats (290–320 g, 10–12 weeks) | 1 m from the charge in a transverse prone position | Yes | Swedish army plastic explosive containing explosive m/46, 86% pentaerythritol tetranitrate and mineral oil | 550 kPa in 0.2 ms | Decreased immobility in blast animals that may be due to Hyperarousal 24 h post blast. No deficits at 14- or 35-days post blast | (88) | |
| SD rats (6-month-old) | Placed outside with right side of the skull facing the pressure wave | No | Nitrogen | 50 Psi in 1 ms | At 72 h post blast | (54) | |
| Light/dark box emergence test | LE rats (250–350 g, 10–12 weeks old) | Head facing the shockwave exposure | Yes | Compressed air | One 74.5 kPa exposure for 3 consecutive days | At week 11 post blast | (62) |
| SD rats (300g) | 19 cm from the nozzle opening at an angle of 21° from the vertical axis of the shock tube. | Not mentioned | Nitrogen gas | 28 kPa | Up to 9 days | (86) | |
| LE rats (250 g−350 g; 10 weeks of age) | Head facing the blast exposure | Yes | Compressed air | 74.5 kPa | At 29 weeks post blast | (65) | |
| Male SD rats 250-300g | Rostral cephalic orientation toward shock wave | Not mentioned | Compressed helium | 10,14, 24 psi | At 7 days post blast in the 10 & 14 psi group. | (89) | |
| SD rats (250 g) | 1.09 m from open end of the blast tube in a rostral cephalic position | Yes. No information on head restraint | Helium | 117 kPa at 2.5 ms | Significantly decreased time 1- and 3-months post blast to enter dark box but no difference in time spent or number of transitions | (36) | |
| C57BL/6J mice (2–month-old) | Prone position 3, 4, and 7 m distances away from the source with the head longitudinally aligned to the shockwave propagation | No | C4 explosives | ~46.6 kPa, ~31.9 kPa and ~19.6 kPa corresponding to 3, 4, and 7 m distances from source. | 5 days post injury in the 3 m blast group | (58) | |
| LE rats (250–350 g) | 18 inches inside the shock tube, both facing and sideways to the blast | Yes | Compressed air | 74.5 kPa for 3 days | Two animals developed deficits while 6 animals showed no deficits, 3 weeks post injury. At 6 months post injury, 9 animals were unaffected while 3 animals showed deficits. |
(84) | |
| Acoustic Startle | Male SD rats (150–200 g) | 265 mm from the exploding wire with head facing impact | No head restrained; movement restricted | Exploding wire technique to generate small scale blast waves | 95 kPa for 0.189 ms | At days 38 and 62 post impact. | (47) |
| Predator Scent Challenge (open field and light /dark emergence test) | LE rats (250–350 g, 10 weeks old) | 30 cm inside the shock tube with head facing the blast exposure | Yes | Compressed air | 74.5 kPa for 3 days | At 3 days in open field test and at 7 days in light/dark emergence task post exposure to predator scent | (50) |