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Monday 19 December 2022 4:38pm

Joon Kim sitting on a rock in a forest next to a stream
Dr Joon Kim

Research designed to better understand what happens inside our brains when we feel anxious could unlock more effective ways of treating anxiety disorders.

“During my third year I attended a lecture by Professor Greg Anderson on gene mutation that blew my mind. It made me interested in how the brain works.”

Dr Joon Kim (Physiology) is aiming to produce the first evidence of how neural circuits in the brain control anxiety. He is experimenting with mice but says the research can readily translate to humans because the neurons in the brain that control stress are identical.

Kim is recording activity in stress neurons – called corticotropin-releasing hormone (CRH) neurons – in mice using a machine he and his mentor, Dr Karl Iremonger, developed in the absence of any commercial products that could do the job.

Special proteins are introduced in the mice to make their stress neurons glow when they are active, and this light is recorded via a tiny optical implant connected to the machine. The stress neurons are activated by playing harmless noise to the mice for a few minutes, which they perceive as a potential danger.

Kim says current anxiety research is mostly behavioural, and he wants to take a more mechanistic approach to what is happening in the brain when a person feels anxious.

He has previously identified how acute elevations in stress neural activity in mice are associated with a switch from low- to high-anxiety behaviours.

Kim's current research is examining how CRH neurons cause this anxiety switch in the brain. This involves understanding how CRH neurons communicate with other neurons to cause this changed anxiety state. He says understanding how the brain flips this switch in anxiety states is essential to understanding when, and how, things go wrong.

The research fellow says current anxiety treatments are largely based on trial and error, and have a broad range of effects. However, by understanding the biological mechanisms by which the brain gives rise to anxiety, his research could have the potential to provide new therapies that target the specific mechanisms in the brain that cause anxiety.

Kim was born in South Korea and emigrated to New Zealand with his family at the age of six. He went to school in Christchurch before studying Anatomy at the University of Otago.

“During my third year I attended a lecture by Professor Greg Anderson on gene mutation that blew my mind. It made me interested in how the brain works.”

He completed a PhD under Anderson and worked for several years as a research fellow in Iremonger's laboratory, studying stress hormones, before launching his own research programme last year, thanks to Marsden Grant funding from the Royal Society Te Apārangi. A postgraduate student, Isaac Tripp, is assisting with the research.

And what stresses the stress researcher? “I don't get stressed by work so much as little things like burning dinner or when fly fishing and you see a fish blatantly refusing your fly,” Kim confesses.

Recent awards

  • New and Emerging Researcher Prize, Physiological Society of New Zealand (2021)
  • Brain Health Research Centre Emerging Researcher Award (2020)
  • Exceptional PhD thesis (2016)
  • John Hubbard Memorial Prize by Physiological Society of New Zealand (2016)


  • Lottery Health Research Post-Doctoral Fellowship
  • Marsden Fund Fast-Start Grant

More stories about early career researchers

This story is part of the research publication 'He Kitenga 2022: Talented Futures', which presents the different pathways into research that early career researchers follow.

Read more 'He Kitenga 2022' research stories

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