The KF belongs to the pontine respiratory group. It is attributed to the control of upper airway resistance and to the adaptation of the breathing pattern to sensory inputs from the pulmo-tracheal tree. In recent publications, we have illustrated that the KF undergoes substantial postnatal maturation in the rat. Further, we have correlated KF immaturity with the lack of plasticity in the respiratory network during the mediation of afferent inputs.

In the present study, we labelled KF neurones (Biocytin and Avidin-Cy3) at different postnatal stages after their initial electrophysiological characterisation (see poster Kron et al.). Comparative analyses of changes in neurone morphology during development revealed a progressive increase in the size of neuronal somas as well as dendritic arborisations. Furthermore, we observed pronounced changes in the orientation of the main dendritic branches. In neonates, short dendrites showed a diffuse orientation while in juveniles, neurones displayed enlarged dendrites with a predominant medio-lateral orientation.

We conclude that, while a basic breathing activity can be generated at birth, essential parts of the respiratory network undergo substantial maturation after birth.

Supported by the DFG ,CMPB