Female cricket brain pinpointed

Researchers believe they have pinpointed the neuronal networks of female crickets responsible for recognising the calling songs of males.

CAMBRIDGE, ENGLAND, UK (BERTHOLD HEDWIG) – A tiny group of neurons in the brains of female crickets are responsible for helping the insect recognise the songs of courting males, according to new research.

Researchers led by Dr Stefan Schöneich and Dr Berthold Hedwig, of the University of Cambridge, pinpointed the neuronal network responsible by playing an audio recording of the mating call of male crickets to females walking on a track ball. The females responded by walking towards the direction of the sound of those males whose oral patterns they preferred.

Reporting their findings in Science Advances, published by the American Association for the Advancement of Science (AAAS), a non-profit science society, Schöneich et al. said the neuronal network in the cricket brain could be a blueprint for auditory neuronal networks in other species.

Animals that use sound to communicate must differentiate between songs made by their own species and those of others, including those emitted by a predator. They rely on brain circuits to process and identify these signals.

To discover what makes crickets so good at recognising calling songs, Schöneich and colleagues recorded the activity of auditory neurons in crickets’ brains using tiny microelectrodes that measure electrical impulses.

While playing various sound patterns to the insects, the researchers found that only some of the auditory neurons were activated in the female crickets. They discovered that a network of just five neurons is activated specifically in response to the male cricket’s calling song. These neurons, called auditory feature detectors by Schöneich’s team, might form the basis for sound recognition in crickets.

According to Hedwig, “the significance of this finding, is that for the first time we have a proper neuronal circuit that can process auditory signals as required for temporal pattern recognition. We identified one circuit in an insect brain, but many of these circuits, with slightly different tuning, could be present in more complex brains to process rhythms or patterns of sound signals.”

He told Reuters: “We now aim to work out how the described circuit is linked to other parts of the cricket brain. We want to understand what happens in the neural circuits that control the animal’s behaviour after the song pattern has been recognized. This is still an open question.”

Schöneich and his colleagues conducted their research in conjunction with a team from Karl-Franzens University in Austria.