Armen Saghatelyan, Ph.D.
Full Professor
Canada Research Chair in postnatal neurogenesis
Department Psychiatry and Neuroscience, Université Laval
Studying the birth of new neurons in the brain to discover new approaches for the treatment of neurodegenerative and neurodevelopmental diseases.
Research in Dr. Armen Saghatelyan’s laboratory aims to better understand how new neurons are born and integrated in the adult brain. The adult brain contains stem cells that divide to generate new neurons. Dr. Saghatelyan's team is interested in the molecular and cellular mechanisms underlying stem cell division, neuronal precursor migration and the integration of new neurons in the adult brain. The olfactory bulb, which is involved in the perception and discrimination of odors, is one of the regions of the brain that renews itself most thanks to a constant production of new neurons. Professor Saghatelyan's team has made a significant contribution to understanding the mechanisms underlying the migration of new neurons and the reorganization of the neural network in the olfactory bulb.
Dr. Saghatelyan's team recently showed that new neurons generated in the olfactory bulb can respond quickly to changes in the environment by modifying their architecture to allow new connections with surrounding neurons, leading to rapid changes in neural networks. The discovery of this new form of structural modification explains the rapid adaptation capacity of the olfactory bulb network.
Dr. Saghatelyan's team has also identified some of the factors and processes that promote the migration of neuronal precursors under normal conditions and after damage to certain areas of the brain induced by lack of oxygenation (called ischemia). They have shown that blood vessels, glial cells, and trophic factors all play a role in this process. Their results suggest that migration of cells to ischemic regions uses similar pathways as developing neurons and follow blood vessels for guidance.
Research in the Saghatelyan laboratory highlights several mechanisms and factors underlying the birth, migration and integration of new neurons in the brain. This understanding can be used to increase the regenerative capacity of the brain, guide newly generated cells to injured brain regions, and control the integration of new neurons into damaged brain regions.
Our lab is interested in the understanding of molecular and cellular mechanisms governing migration, maturation and functional integration of new neurons into the mature neuronal circuitry. The olfactory bulb (OB) is an ideal system to study these processes since it is one of the few regions in the adult brain where massive neuronal migration and integration occurs. Neuronal precursors are generated in the subventricular zone (SVZ) and migrate toward the OB where they integrate into the functional circuitry. The long-term objective of our research is to identify the molecular and cellular programs orchestrating neuronal development in the adult brain that can be used to build up efficient cell replacement therapies by inducing neuronal recruitment into the brain areas affected by neurodegenerative diseases and brain trauma.
We use multidisciplinary approaches including in vivo two-photon imaging of neuronal maturation and spine dynamic, time-lapse imaging of neuronal migration in the acute brain slice, electrophysiology, Ca2+ imaging, cell culture, stereotaxic injection of viral vectors, electroporation, immunohistochemistry, western blotting, as well as behavioral assessment of odor behavior.
Marina Snapyan (research assistant)
Qian Li (postdoctoral fellow)
Archana Gengatharan (PhD student)
Delphine Hardy (PhD student)
Karen Bakhshetyan (PhD student)
Cedric Bressan (PhD student)
Sarah Malvaut (PhD student)
Arutyun Bagramyan (PhD student, co-direction)
Marcos Schaan Profes (PhD student, co-direction)
1. Breton-Provencher V, Bakhshetyan K, Hardy D, Bammann RR, Cavarretta F, Snapyan M, Côté D, Migliore M, Saghatelyan A (2016) Principal cell activity induces spine relocation of adult-born interneurons in the olfactory bulb. Nat Commun. 7:12659. doi: 10.1038/ncomms12659
2. Bagramyan A, Galstian T, Saghatelyan A (2016) Motion-free endoscopic system for brain imaging at variable focal depth using liquid crystal lenses. J Biophotonics. doi: 10.1002/jbio.201500261.
3. Gengatharan A, Bammann RR and Saghatelyan A (2016) The role of astrocytes in the generation, migration and integration of new neurons in the adult olfactory bulb. Frontiers in Neurogenesis doi: 10.3389/fnins.2016.00149.
4. Malvaut S and Saghatelyan A (2016) The role of adult-born neurons in the constantly changing olfactory bulb network. Neural Plasticity. doi:10.1155/2016/1614329.
5.Bakhshetyan K and Saghatelyan A (2015) Tracking neuronal migration in adult brain slices. Curr Protoc Neurosci. 71: 3.28.1-3.28.13. doi: 10.1002/0471142301.ns0328s71
6. Breton-Provencher V, Coté D, Saghatelyan A (2014) The activity of the principal cells of the olfactory bulb promotes a structural dynamic on the distal dendrites of immature adult-born granule cells via activation of NMDA receptors. J Neurosci. 34:1748-59.
7. David L, Schachner M, Saghatelyan A (2013) The extracellular matrix glycoprotein tenascin-R affects adult but not developmental neurogenesis in the olfactory bulb. J Neurosci. 33:10324-39.
8. Bozoyan L, Khlghatyan J, and Saghatelyan A (2012) Astrocytes control the development of the migration-promoting vasculature scaffold in the postnatal brain via VEGF signaling. J Neurosci. 32:1687-704.
9. Breton-Provencher V and Saghatelyan A (2012) Adult olfactory bulb neurogenesis and odor behavior. Behav Brain Res 227: 480-9.
10. Bastien-Dionne P-O, David L, Parent A and Saghatelyan A (2010) Unilateral sensory deprivation alters adult neurogenesis in the olfactory bulb. Journal of Comparative Neurology 518:1847-61.
11. Massouh M and Saghatelyan A (2010) De-routing neuronal precursors in the adult brain to sites of injury: role of the vasculature. Neuropharmacology 58:877-83.
12. Breton-Provencher V, Lemasson M, Peralta MR and Saghatelyan A (2009) Continuous supply of interneurons during adulthood is required for the normal functioning of the olfactory bulb network. J Neurosci. 29: 15245-57. Selected by the Faculty 1000 as a must read article.
13. Saghatelyan A (2009) Role of blood vessels in the neuronal migration. Semin Cell Dev Biol. 20:744-50.
14. Snapyan M, Lemasson M, Brill MS, Blais M, Massouh M, Ninkovic J, Gravel C, Berthod F, Götz M, Barker PA, Parent A and Saghatelyan A (2009) Vasculature guides migrating neuronal precursors in the adult mammalian forebrain via brain-derived neurotrophic factor signaling. J Neurosci. 29:4172-88.
Dr. Armen Saghatelyan is a Full Professor at Laval University and holds Canada Research Tier II in postnatal neurogenesis. He received B.Sc. and Master degrees at Yerevan State University, Armenia and performed 1.5 years pre-docotral training in Saint-Petersburg, Russia. He then did his PhD work in Hamburg, Germany, in the lab of Prof. Melitta Schachner. During his PhD he studied the role of different cell adhesion and extracellular matrix molecules in the formation and function of inhibitory synapses. He performed two post-doctoral trainings in France; first, in the lab of Pierre-Marie Lledo, Pasteur Institut working on the olfactory bulb where arrival of new interneurons and formation of new inhibitory synapses continue throughout life and second, in the lab of Alain Prochiantz, Ecole Normale Superieure, Paris working on the role transcriptional factors in the fate specification of newborn bulbar interneurons.
He obtained Canada Research Chair and joined Laval University in November 2005.
Dr. Saghatelyan is interested in the molecular and cellular mechanisms governing adult olfactory bulb neurogenesis and their potential in treating neurodegenerative diseases.
2005 - 2015 Canada Research Chair in postnatal neurogenesis (Tier II)
2601 Chemin de la Canardière
Québec (Québec)
G1J 2G3
Canada
