de Castro D, Lipski J, Kanjhan R
Department of Physiology, School of Medicine, University of Auckland, New Zealand.
Brain Res. 1994 Mar 7;639(1):49-56. doi: 10.1016/0006-8993(94)91763-9.
There has been controversy whether the dorsal respiratory group (DRG), identified in the cat and several other species as a concentration of mainly inspiratory neurons located in the ventrolateral subnucleus of the solitary tract, also exists in the rat. The aim of this study was to re-examine this question by systematically exploring this region with extracellular microelectrodes, in anesthetized and artificially ventilated rats. One-hundred and forty-two units were recorded which fired in phase with central respiratory cycles (determined by recording from the phrenic nerve) and/or lung inflations. One-hundred and nineteen recordings were thought to be from neuronal cell bodies (confirmed in some cases by excitatory responses to microelectrophoretic administration of DL-homocysteic acid), while the remaining 23 were from lung vagal afferents. Most neurons in the former group (87/119) were inspiratory. Out of 96 neurons tested for spinal projections only 14 (12 inspiratory, 2 expiratory) responded antidromically following stimulation at C3 segment. These results confirm the existence of the DRG in the rat and demonstrate that neurons located in this region have firing patterns generally similar to those previously described in the cat. The main difference is the relative paucity in the rat of neurons projecting spinally below the C2 level, which indicates that most DRG neurons in this species do not project directly to phrenic and intercostal motoneurons, but to other, as yet unidentified, neuronal groups within the brainstem or upper cervical segments.
在猫和其他几个物种中被确定为主要位于孤束腹外侧亚核的吸气神经元集中区域的背侧呼吸组（DRG）在大鼠中是否也存在一直存在争议。本研究的目的是通过在麻醉和人工通气的大鼠中用细胞外微电极系统地探索该区域来重新审视这个问题。记录了142个与中枢呼吸周期（通过膈神经记录确定）和/或肺充气同步放电的单位。119个记录被认为来自神经元细胞体（在某些情况下通过对微电泳给予DL-高半胱氨酸的兴奋性反应得到证实），而其余23个来自肺迷走传入神经。前一组中的大多数神经元（87/119）是吸气性的。在测试脊髓投射的96个神经元中，只有14个（12个吸气性，2个呼气性）在C3节段刺激后出现逆行反应。这些结果证实了大鼠中DRG的存在，并表明位于该区域的神经元具有与先前在猫中描述的大致相似的放电模式。主要区别在于大鼠中脊髓投射低于C2水平的神经元相对较少，这表明该物种中的大多数DRG神经元不直接投射到膈神经和肋间运动神经元，而是投射到脑干或上颈段内的其他尚未确定的神经元群。
