Academic Profile

Academic Profile

Assoc Prof Ajai Vyas

Associate Professor, School of Biological Sciences
Assistant Dean (Academic)

Assoc Prof Ajai Vyas

I am currently Associate Professor at School of Biological Sciences in NTU.

I studied agriculture in BSc and then conducted research into soil microbiology during my masters at Indian Agricultural Research Institute. I finished my PhD at for Biological Sciences working on the effect of immobilization stress on brain and hormones of animals.

I joined NTU in early 2009 after a stint at Stanford University as a post-doctoral scholar. My current research interests pertain to Toxoplasma gondii; a parasite of importance to the livestock industry. I am interested in epidemiology and proximate biology of Toxoplasma infection.
Research Interests
My main interest is consequences of Toxoplasma gondii infection in its intermediate hosts. Toxoplasma is a protozoan parasite that infects humans and a variety of livestock species. This parasite causes fetal death in sheep and goat when contracted during early and mid-phase of the pregnancy.

Most of Toxoplasma infections in herbivore hosts are initiated through food contaminated with cat fecal material. This is because cats are essential for the sexual phase of Toxoplasma life cycle. Cats are infected when they eat small rodents infected with Toxoplasma, leading to shedding of stable oocysts into the environment in cat poo. Thus the transmission from small rodents to cats provide a bottleneck to Toxoplasma transmission; one that could be useful for control of Toxoplasmosis. I am interested in how Toxoplasma circumvents this bottleneck through biochemical and hormonal subterfuge. I have also shown that Toxoplasma can be sexually transmitted from males to females through ejaculate.

My current research project is situated in Kangaroo Island south of Adelaide. Sheep in this island show remarkably higher rates of Toxoplasmosis compared to mainland South Australia. Conservation authorities are planning to remove all cats from Kangaroo Island in the next few years. This should lead to disruption of Toxoplasma life cycle which needs cats. My goal is to confirm that scientific prediction by measuring epidemiology of Toxoplasma in small rodents and sheep before and after cat removal. This project is in collaboration with the University of Adelaide.
Current Projects
  • Biological mechanisms in rat brain mediating attractive and aversive social behaviors
  • Carpe diem impulsivity: Optogenetic manipulation of the impulsive decision making in rodents
  • Defining the brain circuitry defects that cause dementia
  • Discovering hormones and pheromones mediating mate choice
  • Disentangling trophic and sexual transmission dynamics in a ubiquitous parasite
  • Hormones at the interface between ecology and neurobiology
  • Neurobiology of Toxoplasma infection
  • Potential sexual transmission of Toxoplasma gondii in humans
  • Sexually dimoprhic mechanisms underlying behavioral change in rodent hosts after Toxoplasma infection
Selected Publications
  • Tong, W.H., S. Abdulai-Saiku, and A. Vyas. (2019). Testosterone Reduces Fear and Causes Drastic Hypomethylation of Arginine Vasopressin Promoter in Medial Extended Amygdala of Male Mice. Frontiers in Behavioral Neuroscience, 13(33).

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