[Studies on the origin of different discharge pattern of the two types of phrenic motoneurones by cross-correlation analysis].
Experiments were performed on twenty five anesthetized, paralyzed, vagotomized and artificially ventilated rabbits. Discharges of single phrenic nerve fibers were recorded. According to their discharge patterns, phrenic motoneurones were divided into two types: tonic units (TU) and phasic units (PU). A cross-correlation analysis was done between TU and TU, PU and PU, or TU and PU. In 21/36 pairs of phrenic motoneurones, the cross-correlation histogram showed a significant central peak, which represented synchronization of the pair of units resulting from a common input. There were three types of synchronization: short-term, broad peak and high frequency-oscillatory synchronization. The difference in synchronization number between heterogeneous pairs (1 TU and 1PU, 2/10 showing synchronization) and homogeneous pairs (2 TU or 2 PU, 19/26 showing synchronization) was statistically significant (x2-test, P less than 0.05). These results suggest that TU and PU have different central inputs, which result in their different discharge patterns between the TU and PU.
Hu
J M
JM
Yu
X J
XJ
Zhao
N Q
NQ
Xiao
J
J
D000818:Animals; D004594:Electrophysiology; D005260:Female; D008297:Male; D009046:Motor Neurons / Q000502:physiology*; D010791:Phrenic Nerve / Q000502:physiology*; D011817:Rabbits; D012119:Respiration