How Zebrafish Sheds Light on Brain Injury Research: Meet Dr. Kanagu Palsamy

June 3, 2023


By Tina Chen

Dr. Kanagaraj Palsamy, fondly known as Kanagu, is no ordinary researcher. Currently a Research Investigator in the Department of Neurology at Michigan Medicine, he has been an integral part of the University of Michigan community since 2015. His journey began in Dr. Jack Parent’s laboratory as a post-doctoral research fellow, where he delved into the intricacies of brain injury, neuroinflammation, brain regeneration, and epilepsy disease modeling using a seemingly humble organism: the zebrafish. Kanagu has been working with zebrafish for 12 years and utilizing this remarkable animal for biomedical research to improve human life. Dr. Parent’s earlier work on epilepsy-induced aberrant neurogenesis in rats paved the way for adult neurogenesis in the mammalian brain.

Dr. Palsamy’s fascination with zebrafish as a preclinical research model started during his doctoral studies at Goettingen University in Germany. Leveraging his developmental biology training and skills acquired during his Master’s degree, he chose zebrafish for their unique breeding attributes that made them an excellent model for studying the central nervous system. Zebrafish shares 70% genetic homology with human and has almost all mammalian anatomical counterparts. Most importantly, they are amenable to pharmaceutical and genetic manipulations and suitable for live imaging with transgenic fish lines to monitor the development and physiological changes and suitable for robust drug screening for cures.

His first research focus was early development, particularly influenced by “maternal genetic mutations.” By inducing mutations in zebrafish mothers and mating them with normal/wild-type males, he could study the impacts on embryonic development. During his PhD, his mentor discovered several genetic mutants linked to early development and neurodegenerative disease in zebrafish. Interestingly, these observable characteristics are named with culinary terms, specifically, around eggs due to their severe defect in egg development during oogenesis. They are sunny side up, over-easy, ruehrei (German: scrambled eggs), and souffle/SPG15. Kanagu studied the souffle phenotype in zebrafish to understand the human disease, which shed light on how SPG15 mutation manifests early developmental defects and how, in humans, it induces progressive motor neuron degenerative disease called Hereditary Spastic Paraplegia (HSP). 

The zebrafish’s transparency, especially during the embryonic phase, made it possible to observe live developments without causing harm to the creatures (See more: NIHCD Zebrafish Development). Moreover, the prolific breeding of zebrafish – one female can produce around 300 embryos weekly – provided ample subjects for in vivo research,  the embryo develops outside and completes the whole animal development in 48 hours. In addition, zebrafish have a phenomenal capability to regenerate almost every part of their brain after injury (Kanagaraj et al., 2022 Biorxiv

Youtube: WIRED Science, “Zebrafish Brain”

Ultimately, Dr. Palsamy aims to translate his preclinical findings from zebrafish research into practical solutions to promote human brain repair. Kanagu focuses on immune cells’ reaction and role in promoting brain repair after injury. Intrigued by the field of concussion research, Kanagu contemplated the similarities and differences between zebrafish and humans when it comes to concussion symptoms and responses. By carefully administering controlled needle-induced brain injuries or non-penetrating forces to induce concussions in zebrafish brains, these experiments will contribute to a deeper understanding of concussions and their impact on zebrafish, potentially paving the way for future collaboration with Concussion Center members. He wants to study how zebrafish repair their brain when subjected to TBI using the weight drop method and how repeated TBI/concussion in their early life period will affect their regenerative ability and cognitive behaviors. 

When he is not conducting research or writing grant applications, Dr. Palsamy leads an active life. A sports enthusiast, he has participated in the cricket national league in Germany, enjoys badminton, and has a passion for dance. He is also a food connoisseur and can recommend some excellent places for authentic Indian food in Ann Arbor, such as Everest Sherpa and Shalimar on Main Street.