Respiratory bursts at the midline of the rostral medulla of the lamprey
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Periodic bursts of small spikes were recorded at the midline at the rostral level of the V motor nuclei. These occurred prior to bursts by respiratory motoneurons in the IX–X cranial nerve roots (Fig. 1).
The bursts at the midline could be generated in the rostral half of the medulla, since they continued after isolation of the isthmic-trigeminal region by transections (Fig. 2).
Stimulation at the rostral midline excited respiratory motoneurons monosynaptically (Fig. 3) and could entrain or reset the respiratory rhythm (Figs. 4, 5).
Sections of the midline sparing the rostral site still permitted bilateral synchronization of respiratory bursts (Fig. 7).
Alternatively, sections of the rostral midline still allowed coordination of respiratory bursts through crossed caudal pathways, although abnormal timing patterns were observed (Fig. 8).
It is concluded that the motor pattern for respiration is partly generated and coordinated in the rostral half of the medulla of the lamprey and is transmitted to respiratory motoneurons through descending pathways.
KeywordsNerve Root Respiratory Burst Motor Pattern Motor Nucleus Timing Pattern
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- Jüch PJW, Luiten PGM (1981) Anatomy of respiratory rhythmic systems in brain stem and cerebellum of the carp. Brain Res 230:51–64Google Scholar
- Kawasaki R (1979) Breathing rhythm-generation in the adult lamprey,Entosphenus japonicus. Jpn J Physiol 29:327–338Google Scholar
- Kawasaki R (1981) Artificial pacemaking of breathing movements by medullary stimulation in adult lampreys. Jpn J Physiol 31:571–583Google Scholar
- Kawasaki R (1984) Breathing rhythm-generation mechanism in the adult lamprey (Lampetra japonica). Jpn J Physiol 34:319–335Google Scholar
- Luiten PGM, van der Pers JNC (1977) The connections of the trigeminal and facial motor nuclei in the brain of the carp (Cyprinus carpio L.) as revealed by anterograde and retrograde transport of horseradish peroxidase. J Comp Neuroll 174:575–590Google Scholar
- Nieuwenhuys R (1977) The brain of the lamprey in a comparative perspective. Ann NY Acad Sci 299:97–145Google Scholar
- Rovainen CM (1967) Physiological and anatomical studies on large neurons of central nervous system of the sea lamprey (Petromyzon marinus). I. Müller and Mauthner cells. J Neurophysiol 30:1000–1023Google Scholar
- Rovainen CM (1974) Synaptic interactions of reticulospinal neurons and nerve cells in the spinal cord of the sea lamprey. J Comp Neurol 154:207–223Google Scholar
- Rovainen CM (1977) Neural control of ventilation in the lamprey. Fed Proc FASEB 36:2386–2389Google Scholar
- Rovainen CM (1982) Neurophysiology. In: Hardisty MW, Potter IC (eds) The biology of lampreys, vol 4A. Academic, London, pp 1–136Google Scholar
- Rovainen CM (1983) A trigeminal component of the central pattern generator for respiration in the adult lamprey. Soc Neurosci Abstr 9:541Google Scholar
- Russell DF (1984) Respiratory neurons near the trigeminal nucleus in lampreys. Soc Neurosci Abstr 10:754Google Scholar
- Russell DF (1985) Respiratory pattern generation in adult lampreys (Lampetra fluviatilis): interneurons and burst resetting. J Comp Physiol A (in press)Google Scholar
- Thompson KJ (1985) Organization of inputs to motoneurons during fictive respiration in the isolated lamprey brain. J Comp Physiol A 157:291–302Google Scholar