Glutamatergic inputs from the pedunculopontine nucleus to midbrain dopaminergic neurons in primates:Phaseolus vulgaris-leucoagglutinin anterograde labeling combined with postembedding glutamate and GABA immunohistochemistry

作者：Ali Charara, Yoland Smith, André Parent · 发表于：The Journal of Comparative Neurology · 年份：1996 · DOI：10.1002/(sici)1096-9861(19960108)364:2<254::aid-cne5>3.0.co;2-4 · 被引用次数：268 · 研究领域：Neuroscience and Neuropharmacology Research、Neurotransmitter Receptor Influence on Behavior、Neural dynamics and brain function

To verify the possibility that the pedunculopontine nucleus is a source of glutamatergic terminals in contact with midbrain dopaminergic neurons in the squirrel monkey, we used the anterograde transport of Phaseolus vulgaris-leucoagglutinin in combination with preembedding immunohistochemistry for tyrosine hydroxylase and for calbindin D-28k and postembedding immunocytochemistry for glutamate and for gamma-aminobutyric acid. Following tracer injections in the pedunculopontine nucleus, numerous anterogradely labeled fibers emerged from the injection sites to innervate densely the pars compacta of the substantia nigra and ventral tegmental area. The major type of labeled fibers were thin with multiple collaterals and varicosities that established intimate contacts with midbrain dopaminergic neurons. At the electron microscopic level, the anterogradely labeled boutons were medium sized (maximum diameter between 0.9 microns and 2.5 microns) and contained numerous round vesicles and mitochondria. Postembedding immunocytochemistry revealed that 40-60% of anterogradely labeled terminals were enriched in glutamate and formed asymmetric synapses with dendritic shafts of substantia nigra and ventral tegmental area neurons. In triple-immunostained sections, some of the postsynaptic targets to these terminals were found to be dopaminergic. In addition, 30-40% of the anterogradely labeled terminals in both regions displayed immunoreactivity for gamma-aminobutyric acid and, in some cases, ...