Developmental changes in the BDNF-induced modulation of inhibitory synaptic transmission in the Kölliker–Fuse nucleus of rat
Article first published online: 4 DEC 2007
European Journal of Neuroscience
Volume 26, Issue 12, pages 3449–3457, December 2007
How to Cite
Kron, M., Zhang, W. and Dutschmann, M. (2007), Developmental changes in the BDNF-induced modulation of inhibitory synaptic transmission in the Kölliker–Fuse nucleus of rat. European Journal of Neuroscience, 26: 3449–3457. doi: 10.1111/j.1460-9568.2007.05960.x
- Issue published online: 4 DEC 2007
- Article first published online: 4 DEC 2007
- Received 19 July 2007, revised 12 September 2007, accepted 24 October 2007
- developmental neurobiology;
- respiratory centres
The Kölliker–Fuse nucleus (KF), part of the pontine respiratory group, is involved in the control of respiratory phase duration, and receives both excitatory and inhibitory afferent input from various other brain regions. There is evidence for developmental changes in the modulation of excitatory inputs to the KF by the neurotrophin brain-derived neurotrophic factor (BDNF). In the present study we investigated if BDNF exerts developmental effects on inhibitory synaptic transmission in the KF.
Recordings of inhibitory postsynaptic currents (IPSCs) in KF neurons in a pontine slice preparation revealed general developmental changes. Recording of spontaneous and evoked IPSCs (sIPSCs, eIPSCS) revealed that neonatally the γ-aminobutyric acid (GABA)ergic fraction of IPSCs was predominant, while in later developmental stages glycinergic neurotransmission significantly increased. Bath-application of BDNF significantly reduced sIPSC frequency in all developmental stages, while BDNF-mediated modulation on eIPSCs showed developmental differences. The eIPSCs mean amplitude was uniformly and significantly reduced following BDNF application only in neurons from rats younger than postnatal day 10. At later postnatal stages the response pattern became heterogeneous, and both augmentations and reductions of eIPSC amplitudes occurred. All BDNF effects on eIPSCs and sIPSCs were reversed with the tyrosine kinase receptor-B inhibitor K252a.
We conclude that developmental changes in inhibitory neurotransmission, including the BDNF-mediated modulation of eIPSCs, relate to the postnatal maturation of the KF. The changes in BDNF-mediated modulation of IPSCs in the KF may have strong implications for developmental changes in synaptic plasticity and the adaptation of the breathing pattern to afferent inputs.