Periodic Reporting for period 3 - BrainPlay (The self-teaching brain)
Reporting period: 2022-08-01 to 2024-01-31
The BrainPlay consortium initiated a far-reaching and diverse investigation into the neural mechanisms of play. We defined avenue of investigation of the self-teaching brain and confronted the problem from various angles. We investigate the neurobiology of animal play (Brecht group), the human play (Bavelier group), the theory of self-teaching (Gütig group) and the synaptic foundations of self-teaching (Schmitz group). These different lines of research are not separate, but are highly integrated. A highlight of our current research was the identification of the lateral columns of the periaqueductal gray (PAG) as a key driver of play. In close collaboration, the Brecht and Schmitz groups showed that inactivating this mid-brain center abolished ticklishness and play and that cells in the lateral columns of the periaqueductal gray are strongly activated by tickling and play. Another very significant advance is an improved understanding of how human video game play compares to animal play. In a recently published paper, the Bavelier group delineated commonalities and differences of human and animal play. Finally, the Gütig group advanced on our understanding of synaptic and adjustments underlying learning in spiking neurons. We’re happy to note that our publications found a broad press coverage reflecting the sustained interest of the public in play.
We will report the work separately for each group even though our research effort is integrated. More details can be found in other parts of our report.
1. Brecht Group
In the second reporting period the work of the Brecht lab together with the Schmitz group published a high-profile paper (Neuron) on the midbrain mechanisms of play. Specifically, the two groups were able to establish the lateral column of the periaqueductal gray as a key driver of rat play behavior. Because the subcortical centers that drive play are poorly understood, this result constitutes a major breakthrough. This work was very well received and widely published in media such as CNN and newspapers such as El Pais.
2. Bavelier Group
The Bavelier group continued with their characterization of human play and its neural bases in the context of video games and in large data set from the video game League of Legend. The Bavelier group further differentiated human and animal play behaviors. This comparative analysis of human play behavior (video games) and animal play meets a central objective of the BrainPlay grant, namely to understand how play differs across the mammalian clade.
3. Gütig Group
The Gütig lab pushed on with their analysis of spike threshold surfaces and the theory of synaptic changes underlying learning in spiking neurons. Importantly, the Gütig group began to test their approach by learning from applying such synaptic learning mechanisms to natural spike trains recorded in vivo. Such an application of synaptic learning theories to natural spike trains will allow our groups to interact more closely and we are currently applying such paradigms to spike trains recorded in the Brecht lab during playing.
4. Schmitz Group
The long-term goal of Schmitz group work is to determine cellular underpinnings of playfulness. Specifically, the Schmitz group investigate the synaptic underpinnings of play behavior. Two results stand out from this work: First, together with Brecht group the periaqueductal gray was identified as a key structure underlying play (see above). Second, the Schmitz group established that glycinergic mechanisms have a decisive role in periaqueductal gray play circuits. This work is being published.
1. Brecht Group
In the second reporting period the work of the Brecht lab together with the Schmitz group published a high-profile paper (Neuron) on the midbrain mechanisms of play. Specifically, the two groups were able to establish the lateral column of the periaqueductal gray as a key driver of rat play behavior. Because the subcortical centers that drive play are poorly understood, this result constitutes a major breakthrough. This work was very well received and widely published in media such as CNN and newspapers such as El Pais.
2. Bavelier Group
The Bavelier group continued with their characterization of human play and its neural bases in the context of video games and in large data set from the video game League of Legend. The Bavelier group further differentiated human and animal play behaviors. This comparative analysis of human play behavior (video games) and animal play meets a central objective of the BrainPlay grant, namely to understand how play differs across the mammalian clade.
3. Gütig Group
The Gütig lab pushed on with their analysis of spike threshold surfaces and the theory of synaptic changes underlying learning in spiking neurons. Importantly, the Gütig group began to test their approach by learning from applying such synaptic learning mechanisms to natural spike trains recorded in vivo. Such an application of synaptic learning theories to natural spike trains will allow our groups to interact more closely and we are currently applying such paradigms to spike trains recorded in the Brecht lab during playing.
4. Schmitz Group
The long-term goal of Schmitz group work is to determine cellular underpinnings of playfulness. Specifically, the Schmitz group investigate the synaptic underpinnings of play behavior. Two results stand out from this work: First, together with Brecht group the periaqueductal gray was identified as a key structure underlying play (see above). Second, the Schmitz group established that glycinergic mechanisms have a decisive role in periaqueductal gray play circuits. This work is being published.
The entire research agenda of our consortium goes beyond the state of the art. What is new is the joining of forces between animal and human neurobiologists, cellular physiology and theoretical neuroscience to unravel the mysteries of play. Our research effort has already greatly altered our understanding of play. Novel human-animal play paradigms have revealed astounding play abilities of rats. The theoretical framework for understanding synaptic modifications during learning has been extended, and key subcortical drivers of play behavior have been identified. Yet, with all that, key neural determinants of play are still unknown and we envision to resolve such questions and that the BrainPlay consortium will enlighten us about the self-teaching brain.