title: Subcellular localization of NAPE-PLD and DAGL-α in the ventromedial nucleus of the hypothalamus by a preembedding immunogold method.
abstract: The hypothalamus and the endocannabinoid system are important players in the regulation of energy homeostasis. In a previous study, we described the ultrastructural distribution of CB1 receptors in GABAergic and glutamatergic synaptic terminals of the dorsomedial region of the ventromedial nucleus of the hypothalamus (VMH). However, the specific localization of the enzymes responsible for the synthesis of the two main endocannabinoids in the hypothalamus is not known. The objective of this study was to investigate the precise subcellular distribution of N-arachidonoylphospatidylethanolamine phospholipase D (NAPE-PLD) and diacylglycerol lipase α (DAGL-α) in the dorsomedial VMH of wild-type mice by a high resolution immunogold electron microscopy technique. Knock-out mice for each enzyme were used to validate the specificity of the antibodies. NAPE-PLD was localized presynaptically and postsynaptically but showed a preferential distribution in dendrites. DAGL-α was mostly postsynaptic in dendrites and dendritic spines. These anatomical results contribute to a better understanding of the endocannabinoid modulation in the VMH nucleus. Furthermore, they support the idea that the dorsomedial VMH displays the necessary machinery for the endocannabinoid-mediated modulation of synaptic transmission of brain circuitries that regulate important hypothalamic functions such as feeding behaviors.
authors.affiliation: Department of Neurosciences, Faculty of Medicine and Dentistry, University of the Basque Country UPV/EHU, 48940, Leioa, Vizcaya, Spain.
authors.forename: Leire
authors.initials: L
authors.lastname: Reguero
authors.forename: Nagore
authors.initials: N
authors.lastname: Puente
authors.forename: Izaskun
authors.initials: I
authors.lastname: Elezgarai
authors.forename: Almudena
authors.initials: A
authors.lastname: Ramos-Uriarte
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Gerrikagoitia
authors.forename: José-Luis
authors.initials: JL
authors.lastname: Bueno-López
authors.forename: Francisco
authors.initials: F
authors.lastname: Doñate
authors.forename: Pedro
authors.initials: P
authors.lastname: Grandes
mesh_terms: D000818:Animals; D005260:Female; D007150:Immunohistochemistry; D008071:Lipoprotein Lipase / Q000032:analysis* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D010739:Phospholipase D / Q000032:analysis* / Q000378:metabolism; D016610:Tissue Embedding; D014697:Ventromedial Hypothalamic Nucleus / Q000201:enzymology* / Q000648:ultrastructure
chemical_list: D008071:Lipoprotein Lipase; D010739:Phospholipase D; C506062:Napepld protein, mouse