(Press-News.org) To study play behaviors in animals, scientists must be able to authentically simulate play-conducive environments in the laboratory. Animals like rats are less inclined to play if they are anxious or restrained, and there is minimal data on the brain activity of rats that are free to play. After getting rats comfortable with a human playmate, tickling them under controlled conditions, then measuring the rats’ squeaks and brain activity, a research team reports on July 27 in the journal Neuron that a structure in rat brains called the periaqueductal gray is essential for play and laughter.
“We know that vocalizations such as laughter are very important in play, which supported the idea that there is some sort of organization signal in the brain regulating this behavior,” says senior author Michael Brecht, a neuroscientist at the Humboldt-Universität zu Berlin. “For example, children check for laughter when they play-fight with each other. If their playmate isn’t laughing anymore, they stop fighting.”
Play is one of the least understood types of behavior, and scientists currently do not know the neural pathways that control the playfulness of humans or other animals. To learn more about the neuroscience of play, these researchers first ensured that the rats they studied were free to move around throughout the experiment. In addition, they gave the rats a few days to get accustomed to their new environment. Once the rats were comfortable, the researchers played games of “chase the hand” with them and tickled the rats on their backs and bellies. Rats don’t laugh the way humans do, but when amused, they do squeak at a high-pitched tone that humans cannot hear. The researchers monitored this sound to ensure that the rats were having fun.
When looking at these animals’ brain activity, the researchers found strong neural responses to both tickling and playing in the lateral column of the periaqueductal gray, or PAG. If this part of the brain was inhibited, the rats stopped engaging in play as much and did not laugh as frequently. On the other hand, if the rats were put in an unfamiliar environment that was designed to provoke anxiety, they also stopped laughing, and the tickling- and play-responsive cells in the lateral column of the PAG decreased their activity.
The PAG is located in the midbrain, and it has been known in the past to control vocalizations and the fight-or-flight response. Play-fighting can also invoke a fight-or-flight response, which might be one explanation for the PAG’s role in play. Prior research has shown that playfulness persists even if the cortex, which controls consciousness, fails to develop, which suggests that play is a more instinctual behavior.
“A lot of people think that play is childish or not a very decisive behavior, but play is underrated,” says Brecht. “In my perception of play, it’s a self-training behavior. Usually, brains serve for controlling behaviors. Play behaviors, however, seem to serve for growing brains.”
Next, the researchers plan on seeing if they observe similar activity in the lateral column of other animals when they are being played with, which could allow them to compare the playfulness of different species. They also plan to see if giving younger rats different play habits might change the way that the lateral column of the PAG develops.
###
This work was supported by Humboldt-Universität zu Berlin, the Bernstein Center for Computational Neuroscience Berlin, NeuroCure Cluster of Excellence, Einstein Center for Neurosciences Berlin, Deutsche Forschungsgemeinschaft, European Research Council. The authors declare no competing interests.
Neuron, Gloveli et al. “Play and tickling responses map to the lateral columns of the rat periaqueductal gray” https://www.cell.com/neuron/fulltext/S0896-6273(23)00477-4
Neuron (@NeuroCellPress), published by Cell Press, is a bimonthly journal that has established itself as one of the most influential and relied upon journals in the field of neuroscience and one of the premier intellectual forums of the neuroscience community. It publishes interdisciplinary articles that integrate biophysical, cellular, developmental, and molecular approaches with a systems approach to sensory, motor, and higher-order cognitive functions. Visit: http://www.cell.com/neuron. To receive Cell Press media alerts, contact press@cell.com.
END
Scientists have pinpointed a genetic cause for virgin birth for the first time, and once switched on the ability is passed down through generations of females.
For the first time, scientists have managed to induce virgin birth in an animal that usually reproduces sexually: the fruit fly Drosophila melanogaster.
Once induced in this fruit fly, this ability is passed on through the generations: the offspring can reproduce either sexually if there are males around, or by virgin birth if there aren’t.
For most animals, reproduction is sexual - it involves a female’s egg being fertilised by a male’s sperm. ...
Neurons are the cells that constitute neural circuits and use chemicals and electricity to receive and send messages that allow the body to do everything, including thinking, sensing, moving, and more. Neurons have a long fiber called an axon that sends information to the subsequent neurons. Information from axons is received by branch-like structures that fan out from the cell body, called dendrites.
Dendritic refinement is an important part of early postnatal brain development during which dendrites are tailored to make specific connections with appropriate axons. In a recently published paper, researchers present evidence showing how a mechanism within the neurons of a rodent involving ...
Kyoto, Japan -- Having control over how a dish is cooked is always a good idea. Taking a hint from the kitchen, scientists appear to have discovered a way to produce a true structure of the rare but naturally-occurring anti-HIV compound Lancilactone C from start to finish.
Its non-cytotoxicity in mammals could make this triterpenoid an ideal candidate for treating AIDS if its biological activity were clear -- and if only it were abundant in nature.
Now, a research group at Kyoto University has succeeded in ...
The research group of YANG Liangbao at the Institute of Health and Medical Technology, Hefei Institutes of Physical Science (HFIPS), Chinese Academy of Science (CAS) has recently developed a surface-enhanced Raman spectroscopy (SERMS) method to automatically capture target molecules in AgNP/MoS2 nano-pockets, which enables highly sensitive and long-duration dynamic detection of some chemical reaction processes.
The results were published in Analytical Chemistry and selected as the front cover.
Surface-enhanced Raman spectroscopy (SERS) is a kind of molecular spectroscopy with fast, highly sensitive, ...
Now that the world has experienced its hottest day in history, it is more urgent than ever for natural and social scientists to work together to address the climate crisis and keep global temperature increases below 2°C. To this end, an international group of esteemed researchers recently published an innovative research paper that highlights the importance of integrating knowledge from natural and social sciences to inform about effective climate change policies and practice. They argue that the concept of tipping points can serve as a bridge ...
Recently, Prof. JIANG Changlong and his research team at the Institute of Solid State Physics, Hefei Institutes of Physical Science (HFIPS) of Chinese Academy of Sciences (CAS), developed and synthesized two highly effective ratiometric fluorescence nanoprobes. These nanoprobes, when combined with the color recognition capabilities of smartphones, enabled the visual and quantitative detection of pesticides in food and environmental water.
The research has been published in Chemical Engineering Journal and ACS Sustainable Chemistry & Engineering.
Carbamate compounds ...
Scientists have found a way to use nanotechnology to create a 3D ‘scaffold’ to grow cells from the retina –paving the way for potential new ways of treating a common cause of blindness.
Researchers, led by Professor Barbara Pierscionek from Anglia Ruskin University (ARU), have been working on a way to successfully grow retinal pigment epithelial (RPE) cells that stay healthy and viable for up to 150 days. RPE cells sit just outside the neural part of the retina and, when damaged, can cause vision to deteriorate.
It ...
This review is written by Dr. Weixing Song from the Department of Chemistry, Capital Normal University. The paper reviewed the toughness and conductive network of existing hydrogel sensors. It emphasized the development status of various hydrogel sensors and highlighted strategies to enhance their mechanical and electrical performance. The findings are valuable for designing components and structures of high-performance wearable hydrogel sensors.
The increasing demand for healthcare IoT devices drives the development of wearable electronics. Electronic skins possess softness, stretchability, and self-healing ...
New Alzheimer’s research from UVA Health suggests that enhanced light sensitivity may contribute to “sundowning” – the worsening of symptoms late in the day – and spur sleep disruptions thought to contribute to the disease’s progression.
The new insights into the disruptions of the biological clock seen in Alzheimer’s could have important potential both for the development of treatments and for symptom management, the researchers say. For example, caregivers often struggle with the erratic sleep patterns caused by Alzheimer’s ...
Introduced in 2004, high-entropy alloys (HEAs) are alloys composed of multiple principal elements in nearly equiatomic proportions. Their unique chemical composition results in a high degree of chemical disorder, i.e. entropy, and produces remarkable properties such as high strength, ductility, and strong wear-and-tear resistance even at high temperatures. Scientists have dedicated a significant amount of attention to developing novel HEAs to help improve the performance of various electrocatalyst materials.
Because they are made up of differing constituent elements, HEAs' atomic-level surface designs can be complex. But unravelling this complexity is crucial, since the surface ...
