Calretinin-immunoreactive neurons in primate pedunculopontine and laterodorsal tegmental nuclei.
Single- and double-antigen localization procedures were used to study the distribution, morphological characteristics and chemical phenotype of neurons containing the calcium-binding protein calretinin in the pedunculopontine and laterodorsal tegmental nuclei of the cynomolgus monkey (Macaca fascicularis). Calretinin was detected in neurons that belonged to a highly heteromorphic and widely distributed subpopulation of the pedunculopontine and laterodorsal tegmental nuclei in the cynomolgus monkey. Double-immunostaining experiments revealed that about 12% of these calretinin-containing neurons displayed immunoreactivity for another calcium-binding protein, Calbindin-D28k. The calretinin/Calbindin-D28k double-labeled neurons had small to medium-sized perikarya, from which emerged a bipolar or multipolar dendritic arborization. Calretinin was also present in approximately 8% of the cholinergic neurons of the pedunculopontine/laterodorsal nuclear complex, as visualized on single sections immunostained for both calretinin and choline acetyltransferase. These calretinin/choline acetyltransferase double-labeled neurons displayed markedly different sizes and shapes, and occurred preferentially in the pars compacta and dissipata of the pedunculopontine tegmental nucleus. Numerous calretinin-immunoreactive fibers were also present within and around the superior cerebellar peduncle. Some of these varicose fibers closely surrounded large non-immunoreactive neurons, as well as large neurons staining positively for choline acetyltransferase. This study provides the first evidence for the existence of calretinin-immunoreactive neurons within the primate pedunculopontine and laterodorsal tegmental nuclei. Our data suggest that calretinin may play a role in the function of the pedunculopontine/laterodorsal nuclear complex by acting either alone or in conjunction with acetylcholine or Calbindin-D28k.
Fortin
M
M
Laboratoire de neurobiologie, Centre de recherche Université Laval Robert-Giffard, Beauport, Québec, Canada.
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D000818:Animals; D001479:Basal Ganglia / Q000166:cytology; D064032:Calbindin 2; D002795:Choline O-Acetyltransferase / Q000032:analysis; D005260:Female; D008252:Macaca fascicularis; D009434:Neural Pathways; D009474:Neurons / Q000737:chemistry* / Q000201:enzymology; D011149:Pons / Q000737:chemistry* / Q000166:cytology; D064030:S100 Calcium Binding Protein G / Q000032:analysis* / Q000276:immunology; D013681:Tegmentum Mesencephali / Q000737:chemistry* / Q000166:cytology; D013788:Thalamus / Q000166:cytology
D064032:Calbindin 2; D064030:S100 Calcium Binding Protein G; D002795:Choline O-Acetyltransferase