Publication of the Year 2004
I. Paarmann, D. Frermann, B.U. Keller, C. Villmann, H.G. Breitinger, and M. Hollmann (2005).
Kinetics and subunit composition of NMDA receptors in respiratory-related neurons.
Journal of Neurochemistry 93(4): 812-824.
doi: 10.1111/j.1471-4159.2005.03027.x
Abstract
NMDA receptors are involved in a variety of brainstem functions such as the generation of breathing rhythms. NMDA receptor currents of preBötzinger complex (PBC) interneurons and nucleus hypoglossus (NH) motoneurons show remarkably fast deactivation kinetics of approximately 30 ms compared to NMDA receptors in the nucleus of the solitary tract (NTS, 320 ms). As NMDA receptor subunit heterogeneity might underlie the observed physiological differences, we examined the expression of six NMDA receptor subunits (NMDAR1, NR2A, NR2B, NR2C, NR2D, and NR3A) plus eight NMDAR1 splice variants in PBC, NH and NTS neurons in young rats using single cell multiplex RT-PCR. Expression of NR2A, NR2B, and NR2D was observed in all three cell types, while NR3A was much more abundant in PBC interneurons, which belong to the rhythm generator of respiratory activity. In NH neurons, the NMDAR1 splice variants NMDAR1-4a and NMDAR1-4b were found. In NTS neurons, instead of NMDAR1-4b, the NMDAR1-2a splice variant was detected. This differential expression of modulatory splice variants might be the molecular basis for the characteristic functional properties of NMDA receptors, particularly their distinct deactivation kinetics.
