A study of the Faculty of Biological Sciences of the Universitat de València has demonstrated that sexual, defensive and aggressive drives of rats are related with the links and the drives that receives the medial amygdala from other parts of the brain. It is the first work that draws a complete map of these links of the amygdala of a mammal, and it has just been published in the magazine ‘Brain Structure and Function’.
The amygdala is a key structure brain in the control of emotional behaviour, in humans and other mammals. A subdivision of this structure, called medial amygdala (by its anatomic position), takes part in the control of social and sexual behaviours, specially in rodents (rats and mice).
It is the first work that draws a complete map of the links of the medial amygdala of a mammal and it is important because it considers three small anatomic subdivisions of this structure, a technically difficult aspect, due the disposition of the encephalon of these parts makes necessary to cross the brain to study the links with injections of tracers injections.
“The amygdala is a key structure brain in the control of emotional behaviours. The alterations of the amygdala intervene in pathologies like for example anxiety disorders, posttraumatic stress and even autism in humans. So, knowing the links of the amygdala is a necessary step to understand how the wrong running of this structure gives rise to these diseases”, affirm Enrique Lanuza, coordinator of the project and professor of the Department of Cellular Biology of the Faculty of Biological Sciences.
Results full an important knowledge cap and contribute to understand neuronal circuits that intervene in the control of emotional behaviour, and specially in the control of sexual behaviour. Despite we do not know the role of these links in human brain, it could be similar.
The published article, Afferent projections to the different medial amygdala subdivisions: a retrograde tracing study in the mouse, is based in the work of the Lab of Functional and Comparative Neuroantomy of the Department of Cellular Biology. The first signatory of the work is Bernardita Cádiz-Moretti, doctor in neuroscience in the Universitat de València and currently professor of the Universidad Andrés Bello de Santiago in Chile. The research has been part of her doctoral thesis.
A study about rats shows the links that this structure have with other areas of the brain, which allow to analyse which type of information arrives and how are circuits that process this information to give a suitable answer. Results reveal that a part of the medial amygdala is strongly linked with the circuits which intervene in the control of the sexual behaviour, while the other part seems to be linked with the circuits which intervene in the control of defensive and aggressive behaviour.
“With the results of this study we can discuss the prevailing notion which explains that each one of these subnuclei intervene in a different way in the control of some sociosexual conducts and we propose, on the other hand, that they work in a cooperative way to give sexual attraction answers”, affirms Bernardita Cádiz-Moretti.
Development of the research
The research has required to inject in the brain of each anaesthetised rat minimal amount of neuroanatomics tracers, which have been analysed lately in the microscope and they have revealed the organizations of links between different areas of the brain. “It is a study of basic science, the final objective is to promote the understanding of the work of the human brain. The amygdala is a neuronal structure evolutionary preserved, so it has an organization very similar between humans and other mammals”, affirms Enrique Lanuza.
“To perform these experiments, the main difficulty we had was to access to these nuclei, said Bernardita Cádiz-Moretti. They are in the most ventral area, and therefore we had to cross all the brain to arrive to them, and moreover, there is a thick trace”. This two factors are those that make easy the diversion of the needle with which the tracer is settled, and a small shift can make the injection fails.
The magazine Brain Structure and Function, of the editorial group Springer, has an impact index of 5,618, which place it in a second position in the classification of the area of anatomy and embryology of the Journal of Citation Reports, a tool to valuate the main publications everywhere. It is the reference magazine in publications of experimental neuroanatomy studies.
The team and the project
Enrique Lanuza is doctor in biological sciences and tenured professor in the Department of Cellular Biology in the Universitat de València. His research focuses on neuronal circuits that underlie in innate behaviours, like for example the sexual attraction, the assault of parental behaviour. Currently, he is codirector of the Master's Degree in Basic and Applied Neurosciences and of the Master's Degree in Neurosciences and Biotechnology in the Universitat. He has published more than 50 articles in international magazines and several book chapters.
During these work, published by the digital version of the magazine in December 2014, Bernardita Cádiz-Moretti was predoctoral grantholder of the Universitat de València in the programme Becas Chile of the government of the Andean country. He got the third prize of scientific divulgation Mi ciencia, mi país (My science, my country) in Chile with the work the smell of desire (El olor del deseo), related with his predoctoral research.
The research has had the financial support of the programme National Programme for Fostering Excellence in Scientific and Technical Research I+D, and the joint financing FEDER (BFU2010-16656 y BFU2013-47688-P).
Furthermore, in the project have participated Marcos Otero García, grantholder FPU (Formation of University Professors) of the Department of Functional Biology of the Universitat de València, and Fernando Martínez García, full university professor of the Department of Functional Biology and now in the Predepartmental Unit of Medicine in the Universitat Jaume I.
Article:
Afferent projections to the different medial amygdala subdivisions: a retrograde tracing study in the mouse. Journal Brain Structure and Function, 221(2), 1033-1065. DOI 10.1007/s00429-014-0954-y
Link: http://link.springer.com/article/10.1007/s00429-014-0954-y
Last update: 23 de march de 2016 07:00.
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