Angelique Paulk

Picture of Angelique Paulk

I have always held a fascination for insects, our local alien neighbors. They perform incredibly amazing behaviours with a fraction of the number of neurons that we have while surviving in the same environment with the same challenges. They see colour, motion, deal with complex olfactory environments, and must constantly deal with the challenges of anything from predators to mating to dodging fly swatters. How do their small brains allow insects to be some of the most successful organisms on the planet?

Along these lines, my past research has been to examine the neural activity of individual neurons in bumblebees (Bombus impatiens).  I used sharp electrode intracellular recording and neuroanatomical techniques to understand how colour and motion are separated anatomically and physiologically in the bumblebee brain.  These data have opened up the possibility that these small brains can integrate multiple visual cues by segregating the information along anatomical pathways.  The next question, though, is what happens when the insect is challenged with competing visual cues?

In this light, my project is to understand the neural mechanisms of attention on the level of neurons. I use bees (Apis mellifera) and vinegar flies (Drosophila melanogaster) to understand how attention operates while making multiunit  electrophysiological recordings of neural activity while presenting competing visual cues. Below are some examples of what I do to better understand how attention operates in bee and fly brains.

Future directions

Along the lines of understanding the structural and functional mechanisms of how the brain can operate to process, integrate the complex sensory world and produce behavior, my main interests are in how all of this information comes together in key central brain areas. How does the visual information integrate with auditory or olfactory information ? How can the brain consolidate this information to produce the appropriate behaviours? By understanding both the physiology and anatomy of organisms with smaller brains, we may be able to crack one of the greatest codes of our time: how does the brain work to integrate the world in meaningful way?

Bee electrophysiology setup

Fly and bee brain recording with light emitting diodes (in green). The ultraviolet, blue, and green LEDs are presented at different frequencies to understand how the bee brain responds differently to the different colours.

 

 

 

The GAL4/UAS system for brain expresssion: You can cross flies, such as a GAL4 to another set of flies (UAS) to get specific expression in the brain (right). I use this to change neural activity in the brains of flies while recording from populations of cells.

Local field potential recordings from the fly brain can give us insight into how flies respond to visual cues when we increase excitation in specific neural circuits.

 

Image of a bee and a fly courtesy of Christina Knuepffer

Publications

 

And just for those of you who scrolled down far enough, some beautiful brains:

Top and middle: Drosophila brains with heads partially dissected away, with a 3D model of areas of the Drosophila brain (middle right). Bottom: a 3D model of the honeybee brain created in Matlab