Neurochemical studies of the nucleus of the solitary tract, dorsal motor nucleus of the vagus and the hypoglossal nucleus in rat: Topographical distribution of glutamate uptake, GABA uptake and glutamic acid decarboxylase activity

The topographical distribution of glutamate uptake, GABA uptake, and GAD activity was studied in caudal, intermediate and rostral areas of the nucleus of the solitary tract (NTS), dorsal motor nucleus of the vagus (DMN) and the hypoglossal nucleus (n.XII). Within the NTS and n.XII, all three neurochemical parameters exhibited increasing activity from caudal to rostral regions. The distribution pattern for glutamate uptake within the DMN was qualitatively similar to the other nuclei studied, whereas GABA uptake and GAD activity were found to be homogeneously distributed within the DMN. The NTS also exhibited a medial-lateral heterogeneity for glutamate and GABA uptake, with the medial aspect of this nucleus containing significantly higher uptake than the lateral aspect.