They might only be small, but desert ants have a powerful skill – they can orient themselves to the Earth’s magnetic field. Where in their brains this information is processed was previously unclear, but by disrupting magnetic fields early in the ants’ development, researchers now believe they’ve uncovered the responsible regions.
In a previous study, the research team discovered that young desert ants go on “learning walks” just outside the nest entrance, spinning around on their body axis and looking back at the nest in order to orient themselves to the Earth’s magnetic field. As study author Pauline Fleischmann put it in a
To figure out which regions of the brain were involved in this process, the team set to manipulating the magnetic field when the
They did this by taking young worker ants that had not yet gone on learning walks and only allowing them to set out for the first time under particular conditions: either a permanently manipulated
The researchers then looked at whether any structural changes had occurred in the ants’ nervous systems. This was relatively simple, as desert ants only have a small nervous system – their brain contains fewer than a million neurons, small fry compared to
“Our neuroanatomical brain analyses show that ants exposed to an altered magnetic field have a smaller volume and fewer synaptic complexes in an area of the brain responsible for the integration of visual information and learning, the so-called mushroom body,” explained Fleischmann and fellow author Robin Grob.
Analysis also showed structural changes in the ants’ central complex, a part of the brain that’s involved in spatial orientation. Under normal circumstances, the ants instead showed an increased number of synaptic connections – the places where neurons link up and chat with each other – in both this region and the
Because these particular regions are involved, the authors suggest that the processing of magnetic information is not just about successful
“Ants need a functioning magnetic compass during their learning walks in order to calibrate their visual compass and at the same time store images of the nest environment in their long-term memory,” stated Fleischmann and Grob.
The researchers also believe that the results deliver an important glance into neuronal development and plasticity across the board, not just in
As for what’s next, the researchers want to achieve something that’s never been achieved with
The study is published in