Owls may make maps of their surroundings in their brains just like humans do. The fact that this ability has been seen in mammals and non-mammals could suggest it evolved hundreds of millions of years ago.
at Technion-Israel Institute of Technology and his colleagues implanted a wireless neural recording device into the brains of six barn owls (Tyto alba), using these to analyse brain activity as they flew back and forth between two perches.
The researchers were looking for evidence of place cells 鈥� neurons that fire when an animal visits a specific place. These cells let an animal make a mental map of its surroundings and have been found in humans, rodents and bats. They have never been recorded in flying birds before, although they have been seen in a tufted titmouse, a type of songbird, as it walks.
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The team recorded each bird for about 20 minutes, tracking flight with eight high-speed infrared cameras, repeating the experiment several times with each bird.
By combining data from the owls鈥� brains with the infrared recordings, the team found that certain hippocampus neurons fired more strongly at specific points in the flight path and depending on which direction a bird was going in. This response was unaffected by lighting changes or movements by the experimenter in the room. Place cells in rodents display similar behaviour.
But the team notes that the cells could instead be time-sensitive and their firing dependent on how long the birds have been in the air. Cells have been found in rodents that fire at distinct time points after the initiation of an action.
at University College London says that she finds the evidence suggesting these neurons are place cells 鈥渇airly convincing鈥�. She says the cells鈥� properties are like those seen in rodents in a similar task that has the animals moving in a straight line.
鈥淭he findings are consistent with emerging findings from other labs that many of the phenomena we have been studying in mammals have counterparts in non-mammals, suggesting an ancient evolutionary origin 鈥� more than 300 million years,鈥� she says.
She says the next step is to try to confirm the existence of these cells in fish. 鈥淲e have seen some spatial encoding in fish, but not actual place cells,鈥� she says. 鈥淭his is technically even more challenging, but I hope it will happen. That would put us even further back in evolutionary time.鈥�
搁别蹿别谤别苍肠别:听bioRxiv, DOI:
