Juvin Laurent, Morin Didier
Universités Bordeaux 1 & Victor Segalen Bordeaux 2, Laboratoire Physiologie et Physiopathologie de la Signalisation Cellulaire, UMR CNRS 5543, Equipe Neurobiologie Adaptative des Systèmes Moteurs, 33076 Bordeaux Cedex, France.
Eur J Neurosci. 2005 Feb;21(3):808-13. doi: 10.1111/j.1460-9568.2005.03910.x.
Isolated brainstem-spinal cord preparations were used to explore the coexistence of a direct and an indirect descending drive from the brainstem respiratory centre to cervical and thoracic respiratory motoneurons in the neonatal Sprague-Dawley rat. Polysynaptic spinal relay pathways from the respiratory centre were suppressed by selectively perfusing the cord with mephenesin (1 mM) or a solution enriched with Ca2+ and Mg2+. At birth, both direct and spinally relayed pathways are functional and contribute equally to the global descending respiratory drive. However, during the first postnatal week, significant maturational changes appear in the way the respiratory centre controls its target respiratory motoneurons in the cervical and thoracic spinal cord, with the direct respiratory drive becoming progressively predominant with maturation (from 50% to around 75% of the global descending command). The relative contributions of the monosynaptic and the polysynaptic spinal pathways may therefore have important implications for effective respiratory control during early postnatal development.
采用新生斯普拉格-道利大鼠的离体脑干-脊髓标本，探究脑干呼吸中枢至颈段和胸段呼吸运动神经元的直接和间接下行驱动的共存情况。通过用美芬新（1 mM）或富含Ca2+和Mg2+的溶液选择性灌注脊髓，抑制呼吸中枢的多突触脊髓中继通路。出生时，直接通路和经脊髓中继的通路均起作用，且对整体下行呼吸驱动的贡献相等。然而，在出生后的第一周，呼吸中枢控制颈段和胸段脊髓中其目标呼吸运动神经元的方式出现了显著的成熟变化，直接呼吸驱动随着成熟逐渐占主导地位（从整体下行指令的50%增至约75%）。因此，单突触和多突触脊髓通路的相对贡献可能对出生后早期发育期间的有效呼吸控制具有重要意义。
