Neuronal Representation of Tool Use in the Crow Brain

01/11/2024 to 31/10/2027

Tool use is a rare behavior that was once considered to be uniquely human. Meanwhile it has been found scattered across the animal kingdom, including observations in mammals, birds, fish and even invertebrates. This complex behavior is particularly common among birds, especially within the group of corvids, which includes crows, jays, jackdaws, magpies, and ravens. Yet, very little is known about how tool use is controlled by the brain.
Crows are corvid songbirds and – in contrast to tool use – the neuronal control of birdsong is relatively well understood. Interestingly, birdsong is a motor behavior that is comparable in complexity to tool use behaviors that have been observed in crows. However, it remains unclear whether the activity patterns of neurons controlling birdsong have specifically evolved for singing or if other complex behaviors of songbirds, such as tool use, share similar neuronal foundations.
Through the investigation of tool use, for the first time, we aim to study the neuronal control of a complex, non-vocal motor behavior in a songbird. The expected results will be compared with the decades of knowledge gained about the neuronal control of birdsong to identify fundamental principles of motor control. Moreover, our experiments will directly test the influential 'motor theory for vocal learning origin', which postulates that vocal and non-vocal complex motor behaviors are based on comparable neuronal principles.
The current proposal aims at studying important premotor areas of the carrion crow (Corvus corone) brain. For this, hand-raised crows will be conditioned to use a wooden stick to access a food reward - essentially, to use a tool. During this behavior, we will record and subsequently analyze the activity of many individual nerve cells in the crows' brains. Additionally, we plan to pharmacologically inactivate the nerve cells presumed to control tool use in a reversible manner. This will help determine to what extent the neuronal networks we are investigating actually control this behavior.
Our comparative approach is an essential pathway to understanding fundamental principles and degrees of freedom in neuronal motor control. Such an understanding will, eventually, aid the development of more flexible 'brain machine interfaces' and better 'deep brain stimulation' targets, with the potential to help a wider range of patients suffering from neurological motor deficits.