Figure 4.

Histogram of the CDP peak amplitudes in the cervical spinal segments (C4 to C7) after phrenic nerve afferent stimulation in cats. N1 is the first peak amplitude observed in the C4 to C7 spinal segments; N2 and N3 are the second and third peak amplitudes only observed in the C5 and C6 spinal segments. * indicates a significant differences between N1 and N2 peaks in the C5 and C6 segmental locations. # indicates a significant difference between N1 and N3 peaks in the C5 and C6 segmental locations. ∞ indicates significant differences between the spinal segments for N1 peak.