Distribution of glutamate receptors in the posterodorsal medial amygdala of adult male rats
Francine Dalpian1, Janaina Brusco2, Maria Elisa Calcagnotto3, Jorge E. Moreira2 and Alberto A. Rasia-Filho1
1Department of Basic Sciences/Physiology, Federal University of Health Sciences of Porto Alegre (UFCSPA), RS, 2Laboratory of Synaptic Structure, Departments of Pathology and Forensic Medicine and Neuroscience and Behavior, Ribeirão Preto School of Medicine, University of São Paulo (FMRP-USP), SP and 3Department of Biochemistry, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
Offprint requests to: Prof. J.E. Moreira, Laboratory of Synaptic Structure, Deparments of Pathology and Forensic Medicine and Neuroscience and Behavior, Ribeirao Preto School of Medicine, University of Sao Paulo (MRP-USP), SP 14049-900, Brazil. e-mail: cello@fmrp.usp.br
Summary. The rat posterodorsal medial amygdala (MePD) has a remarkable neuronal plasticity and responds to olfactory/pheromonal stimuli to modulate emotional and reproductive behaviors. Glutamate is locally released by incoming sensorial pathways to establish and enforce synaptic inputs. Here, we combined DiI dye and immunolabeling procedure under confocal microscopy to describe the presence and distribution of glutamate receptors on neurons of the MePD of adult male rats. Western blot analysis interrogated binding specificity. Both AMPA (GluA1-4 subunits) and NMDA (GluN1 subunit) receptors were immunolabeled on cell bodies and along proximal and distal dendritic shafts. AMPA receptors were mainly observed on mushroom and stubby/wide spines, whereas NMDA receptors were found on thin spines. Colocalization of AMPA and NMDA receptors occurred in some spines. Filopodium did not show immuno-labeled puncta on it. Our results are different from the distribution of glutamate receptors in the amygdaloid lateral nucleus, an upstream area involved with emotional processing, and suggest a region-specific excitatory transmission at proximal and distal dendritic branches. Altogether, these data provide new information for synaptic processing in the MePD likely related to the modulation of social behavior in rats. Histol Histopathol 30, 1303-1311 (2015)
Key words: Extended amygdala, AMPA, NMDA, Neuronal cell body, Dendritic shafts, Spines
DOI: 10.14670/HH-11-626