Table 5.
Auditory deficits in bTBI.
| Behavior test | Rodent used | Position of animal | Head restraint | Gas used in blast tube | Blast pressure | Duration of deficits | References |
|---|---|---|---|---|---|---|---|
| Prepulse inhibition (PPI) and acoustic startle | 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 | Significant increase in PPI in blast animals between weeks 11–17 post blast | (62) |
| 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 | Decreased startle amplitude response 2 weeks post blast but no effects of PPI | (31) | |
| 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 | Increased acoustic startle 24 weeks post blast but had no change in PPI | (50) | |
| LE rats (250 g−350 g; 10 weeks of age) | Head facing the blast exposure | Yes | Compressed air | 74.5 kPa | Enhanced PPI at 34-week post blast | (65) | |
| Gap detection (GAP), acoustic startle reflex and PPI | SD Rats (70–80 days) | 1.09 m from open end of blast tube in a rostral cephalic orientation | Yes, with one ear occluded. No information on head restraint | Helium | 150 kPa for 10ms | Tinnitus positive rats had impaired GAP ratios 24 h, a month and 3 months post blast. PPI ratios were increased only at the 24 h time point. All blast rats had decreased startle force at 24 h, 1 month, and 3-month, time points. | (129) |
| SD rats (110 days old, 250-300g) | 109 cm inside the open end of the blast tube in a rostro-cephalic orientation to the blast wave | Not mentioned. Right ear was occluded with an earplug. | Helium | 3 blast exposures of 22 psi 5 min apart. | Hearing loss and tinnitus up to 7 weeks post blast | (128) | |
| GAP and PPI testing. | Long Evans rats (60–70 days old) | 44 inches from open end of tube in a prone position with head facing blast | No earplugs. Head restraint not mentioned | Helium | 95 kPa for 10 ms | Tinnitus observed at 24 h and at certain frequencies on day 14. The GAP deficits recovered by day 28. PPI deficits pertained at particular frequencies up to day 90. | (130) |
| SD rats (60–70 days) | 503 cm from the bursting membrane and 112 cm from the open end of the driven cylinder | Yes, with no earplugs. Head restraint not mentioned | Helium | 14 Psi | 8 out of 13 rats developed tinnitus, | (53) |
Behavioral tests to measure hearing loss and tinnitus in bTBI rodent models.