title: Synaptic connectivity of the cholinergic axons in the olfactory bulb of the cynomolgus monkey.
abstract: The olfactory bulb (OB) of mammals receives cholinergic afferents from the horizontal limb of the diagonal band of Broca (HDB). At present, the synaptic connectivity of the cholinergic axons on the circuits of the OB has only been investigated in the rat. In this report, we analyze the synaptic connectivity of the cholinergic axons in the OB of the cynomolgus monkey (Macaca fascicularis). Our aim is to investigate whether the cholinergic innervation of the bulbar circuits is phylogenetically conserved between macrosmatic and microsmatic mammals. Our results demonstrate that the cholinergic axons form synaptic contacts on interneurons. In the glomerular layer, their main targets are the periglomerular cells, which receive axo-somatic and axo-dendritic synapses. In the inframitral region, their main targets are the granule cells, which receive synaptic contacts on their dendritic shafts and spines. Although the cholinergic boutons were frequently found in close vicinity of the dendrites of principal cells, we have not found synaptic contacts on them. From a comparative perspective, our data indicate that the synaptic connectivity of the cholinergic circuits is highly preserved in the OB of macrosmatic and microsmatic mammals.
authors: Faculty of Biology, Department of Cell Biology, University of Valencia Burjassot, Valencia, Spain.
authors: Teresa
authors: T
authors: Liberia
authors: Faculty of Biology, Department of Cell Biology, University of Valencia Burjassot, Valencia, Spain.
authors: José Miguel
authors: JM
authors: Blasco-Ibáñez
authors: Faculty of Biology, Department of Cell Biology, University of Valencia Burjassot, Valencia, Spain.
authors: Juan
authors: J
authors: Nácher
authors: Faculty of Biology, Department of Cell Biology, University of Valencia Burjassot, Valencia, Spain.
authors: Emilio
authors: E
authors: Varea
authors: Neurosciences Division, Center for Applied Medical Research (CIMA), University of Navarra Pamplona, Spain ; Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) Pamplona, Navarra, Spain ; Instituto de Investigaciones Sanitarias de Navarra (IdiSNA) Pamplona, Navarra, Spain.
authors: José Luis
authors: JL
authors: Lanciego
authors: Faculty of Biology, Department of Cell Biology, University of Valencia Burjassot, Valencia, Spain.
authors: Carlos
authors: C
authors: Crespo
keywords: acetylcholine; interneurons; non-human primates; olfaction; synapses