Dr Karin Nordstrom

Biography/ Background

2009-present. Swedish Research Council Research Fellow at Uppsala University.

2008 - 2010. ARC Research Fellow: Target detection in visual clutter.

2007 - present. Lecturer in Physiology.

2005-2007. Swedish Research Council Postdoctoral Fellow, Discipline of Physiology. Optimal eye design correlated with the detection of small moving targets in hovering flies.

2004. Postdoctoral Fellow: Discipline of Physiology: Examination of visual motion detection in dragonflies and hoverflies.

2003. PhD in Cell & Organism Biology, Lund University, Sweden. Thesis: "Evolution of eyes: Pax, gene duplications & morphology".

1998. MSc in Zoology, Uppsala University, Sweden. Thesis: "Independent Evolution of Diplopod Vision?"

1994-1998. Undergraduate science, Uppsala University, Sweden.

Research Interests

Visual target detection in hoverflies

Hoverflies are bee mimics and it is likely that you have seen these flies without noticing them. As opposed to bees they do not sting, but also they have larger eyes and are largely visually guided, which make them appealing to the visual scientist. Despite their apparent simplicity, insects analyze the visual world in much the same way as humans and other vertebrates, which make them excellent model systems for investigating visual neurophysiology.

While insects have extremely small brains, and low-resolution eyes, they are remarkably skilled at navigating through 3D surrounds. Many insects also participate in high-speed manoeuvres during activities such as prey pursuit and courtship. These are non-trivial tasks that involve the ability to distinguish objects that move relative to the remaining visual surround. To do this insects utilize specialized neurons in higher-order visual ganglia in the brain.

To understand how hoverflies detect small targets we use sophisticated intracellular electrophysiological recording techniques and state-of-the-art visual display software (developed with David O'Carroll and Russell Brinkworth: http://www.adelaide.edu.au/mbs/research/insect_vision/). This gives us the capacity to deduce what happens within individual neurons in response to visual stimuli that we have complete control over. We have thus been able to show the exquisite ability of some of these target neurons to give a robust response to target motion, even in the presence of confounding moving background clutter. We are currently investigating how this remarkable task is achieved.

We also found that female hoverflies have target neurons despite the fact that this has earlier been described as a male-specific feature. As hoverflies are non-predatory, we hypothesize that female flies utilize these neurons during courtship to enable them to detect fit males for possible mating. We will study this by comparing sex differences of the neurons themselves, and also by analyzing courtship in the field.

Publications

2008. Nordstrom, K, Barnett, PD, Moyer de Miguel, I, Brinkworth, RSA and O'Carroll, DC. "Sexual dimorphism in the hoverfly motion vision pathway". Current Biology, 18(9): 661 - 667.

2007. Geurten, BRH, Nordstrom, K, Sprayberry, JDH, Bolzon, DM and O'Carroll, DC. "Neural mechanisms underlying target detection in a dragonfly centrifugal neuron". J Exp Biol, 210(18): 3277 - 3284.

2007. Barnett, PD, Nordstrom, K and O'Carroll, DC. "Retinotopic Organization of small-field-target-detecting neurons in the insect visual system". Current Biology 17(7): 569-578; doi:10.1016/j.cub.2007.02.039.

2006. Nordstrom, K, Barnett, PD and O'Carroll, DC. "Insect detection of small targets moving in visual clutter". PLoS Biol 4(3): 378-386.

2006. Nordstrom, K and O'Carroll, D. "Small target motion detection neurons in female hoverflies". Proc Roy Soc London B 273(1591): 1211-1216.

2004. Nordstrom, K, Larsson, T and Larhammar, D. "Extensive duplications of phototransduction genes in early vertebrate evolution correlate with block (chromosome) duplications". Genomics 83(5): 852-872.

2003. Nordstrom, K, Scholten, I, Nordstrom, J, Larhammar, D and Miller, D. "Mutational analysis of the Acropora millepora PaxD paired domain highlights the importance of the linker region for DNA binding". Gene 320: 81-87.

2003. Nordstrom, K, Wallen, R, Seymour, J and Nilsson D. "A visual system without neurons in jellyfish larvae". Proc Roy Soc London B 270(1531): 2349-2354.

Entry last updated: Thursday, 10 Sep 2009