Table 2.
Experimental models of SCI used to assess respiratory dysfunction
| Spinal level | Injury model | Recovery | Species |
|---|---|---|---|
| C1 | Complete transection | Spontaneous (but temporary) | Dog [90,91], cat [92], rat [93] |
| C2 | Complete transection | Spontaneous (but temporary) | Dog [90,91], rabbit [94] |
| Lateral hemisection | CPP: induced by contralateral rhizotomy | Dog [41,95], cat [95], rabbit [41,95], rat [96], mouse [42,43], woodchuck [95], guinea pig [58] | |
| Lateral hemisection | CPP: spontaneous | Cat [97], rabbit [97], rat [26,27,37–40] | |
| Incomplete lateral section | Spontaneous phrenic nerve activity, but no diaphragm EMG recovery | Rat [32,34] | |
| Complete transection | Induced by anastomosis and innervation by spared systems | Rat [98] | |
| Lateral hemicontusion | Spontaneous recovery | Rat [44] | |
| Lateral hemicontusion | No recovery | Rat [45] | |
| C4/5 | Midline contusion | Spontaneous recovery | Rat [44] |
| C5 | Lateral hemicontusion | Spontaneous recovery, but enhanced via serotonergic agonists | Rat [28] |
| T8 | Midline contusion | Induced by administration of serotonergic agonists | Rat [54,64] |
This table summarizes some of the injury models that have been used to examine respiratory dysfunction, with reference to potential mechanisms of recovery and the animals used. Note that these examples reflect studies in both male and female animals, at a range of weights and ages. The C2 lateral hemisection (C2HMx) is the most extensively documented model and has provided the most comprehensive evidence for neuroplasticity in the injured respiratory circuitry.