Conspecific odor exposure predominantly activates non-kisspeptin cells in the medial nucleus of the amygdala

Author(s)

Lima, Leandro Bueno ^[1] ; Haubenthal, Fernanda Tais ^[2] ; Silveira, Marina Augusto ^[2] ; Bohlen, Tabata Mariz ^[2] ; Metzger, Martin ^[1] ; Donato Jr, Jose ; Frazao, Renato ^[2]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Physiol & Biophys, Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, Inst Biomed Sci, Dept Anat, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Neuroscience Letters; v. 681, p. 12-16, AUG 10 2018.
• Web of Science Citations: 3

Abstract

A small neuronal subpopulation in the medial nucleus of the amygdala (MeA), expressing the Kiss1 gene, is now considered an important mediator that integrates socio-sexual behavior and odor information in order to modulate the Hypothalamic-Pituitary-Gonadal (HPG) axis. Previous studies demonstrated that exogenous kisspeptin administration or selective activation of Kiss1-expressing neurons in the MeA modulates the onset of puberty, LH secretion and sexual behavior. These functions are supported by the known MeA neuronal connections. In the MeA, as well as in the hypothalamus, Kiss1 mRNA expression mostly depends on sex steroids levels. However, the percentage of Kiss1-expressing cells that co-express estrogen receptor a (ER alpha) in the MeA is currently unknown. Additionally, whether MeA kisspeptin neurons show Fos expression due to pheromone exposure is still undisclosed. In the present study, we used adult male and female mice that express a reporter protein under the Kiss1 promoters to determine the percentage of Kiss1-expressing neurons that co-express the ERa in the MeA and, whether those cells are activated by olfactory cues. We found a high percentage of Kiss1-expressing neurons in the MeA co-expressing the ERa. The proportion of co-expression was similar between male and female mice in diestrus. Interestingly, a low percentage of Kiss1-expressing neurons in the MeA co-express Fos after conspecific odor exposure, despite a significant increase of Fos positive cells in the MeA. Additionally, odor exposition leads to a sexually dimorphic change in Kiss1 expression in the posterior subdivision of the MeA. Our findings suggest that olfactory signals predominantly activate non-kisspeptin cells in the MeA to modulate responses to pheromones and therefore the HPG axis. (AU)

• FAPESP's process: 17/16473-6 - Processing of aversive stimuli: circuitry between the laterodorsal tegmental nucleus, the habenula, and dorsal and median raphe nuclei
• Grantee: Martin Andreas Metzger
• Support type: Regular Research Grants
• FAPESP's process: 15/14588-5 - Influence of leptin sensitivity in mice sexual maturation
• Grantee: Tabata Mariz Bohlen
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 12/12202-4 - Kiss1 neurons biophysical properties modulation by circadian factors
• Grantee: Renata Frazão
• Support type: Regular Research Grants
• FAPESP's process: 17/02983-2 - The role of growth hormone in the brain: relevance for neural functions and in disease
• Grantee: Jose Donato Junior
• Support type: Research Projects - Thematic Grants
• FAPESP's process: 14/08755-3 - Kiss1 neurons activation by pheromonal stimulus
• Grantee: Fernanda Tais Haubenthal
• Support type: Scholarships in Brazil - Scientific Initiation