At the MPINB, we study many different animal species, from worms and flies to fish, frogs, rodents and birds. Common model species for biological research inhabit our animal house like the fruit fly Drosophila melanogaster or the famous roundworm Caenorhabditis elegans as well as mice and rats. But we also study animals that are typically not found in the lab, like the African mole-rat Fukomys anselli, the four-eyed fish Anableps anableps, or the cannibalistic roundworm Pristionchus pacificus.
The African mole-rat, Fukomys anselli, is endemic to central Zambia. It lives in cooperatively breeding family groups and inhabits extensive underground tunnel systems. As the animals live in permanent darkness, they cannot rely on their vision to locate, for example, their sleeping chamber or their food chamber. Their noses and ears and their somatosensory system help them to a limited extend, but they might also rely on a special sense called magnetoreception to orientate: African mole-rats can detect the Earth’s magnetic field. The ability to navigate using magnetoreception is already known from birds and sea turtles, but so far, it is unclear how this sensory system works in mammals. The African mole-rat is one of the few rodents known to be able so sense the Earth's magnetic field and is an excellent model system for studying magnetoreception in rodents.
Our researchers from the Neurobiology of Magnetoreception Lab want to find out more about this fascinating sense. Read more about their research in this article in the magazine Max Planck Research or on the lab's own webpage.
The amazing Anableps anableps is one of the three species of “four-eyed fishes”. These fish do not actually have four eyes, but their eyes are divided in an upper and lower part. The pupils have stretched vertically in the course of evolution and are divided into two halves each by a thin horizontal band of pigment on the cornea. The upper part of the eyes of Anableps anableps is adapted for seeing in air, the lower part for vision underwater. Thus, the fish can see above and below water simultaneously when it swims at the surface. And this is what the fish is mostly doing to catch terrestrial insects above the water surface. Sometimes, it even jumps and catches insects in flight. Anableps anableps is viviparous: the eggs and embryos develop inside the mother's body who then gives birth to young fish.
Anableps anableps is an excellent organism to study vision. Our researchers from the Department of Computational Neuroethology are studying the Anableps retina, the layers of neuronal cells in the eye responsible for converting light stimuli into electrical signals and sending those signals to the brain. By using advanced imaging technology, they are investigating the response of these cells to different visual stimuli and how these cells are connected to each other. Finally, by comparing their results for the aquatic and aerial visual fields, our researchers aim to identify features that help Anableps deal with two very different visual environments simultaneously.
The tiny fly, often referred to as “fruit fly” or “vinegar fly” is a very common organism in biomedical research. The list of fundamental discoveries made in Drosophila is incredible long and already led to 6 Nobel prizes. Despite of the obvious many differences between a fly and a mammal, genes and neural circuits for controlling essential behavior have been found to be conserved during evolution. The short generation cycle and wide array of genetic tools make Drosophila an ideal model to study behavior and also to establish disease models. Genetically modified flies even allow researchers to switch on or off selected neurons using a light stimulus (optogenetics) during behavioral experiments. Thus, researchers can study the function of single neurons and neural circuits in the fly.
Our Neurobiology of Flight Control lab uses Drosophila as a model to study the complex behavior of course control during flight. Watch the interview with Group Leader Bettina Schnell to find out more.
A second lab at the MPINB, our Neural Circuits lab, also works with Drosophila to understand how neural networks in the brain change over time and how these changes relate to behavior. Read our news about the lab's amazing new experimental setup where a fly walks in its own “virtual reality” and about their automated experimental setup that allows to capture the activity of neuronal networks continuously for up to one week while the fly walks, feeds and sleeps.
Laboratory rats belong to the subspecies Rattus norvegicus domestica. They are bred for scientific research and are widely used in biomedical science and psychology. At the MPINB, we are working with freely moving rats to understand the neuronal mechanisms underlying vision-based decision making. To this end, our Department of Behavior and Brain Organization develops miniature multiphoton microscopes and optics-based head and eye tracking techniques that can be used on freely behaving animals. Recently, our researchers also developed a new approach to accurately quantify skeletal kinematics in freely moving rats. This approach will contribute to unraveling the relationship between neuronal activity and complex behavior. Read our press release.
Our In Silico Brain Sciences lab also works with rats, focusing on their whisker system. Rats, like mice and other rodents, actively move their facial whiskers to explore the environment. Our researchers aim at deciphering how the brain is able to transform this sensory input into behavior. They combine anatomical reconstruction of neural circuits, cellular physiology and computational modeling and generate detailed neuronal networks. Read their latest research news.
Even more common than the laboratory rat (see above) is the laboratory mouse. Mice have been used for research on mammals since the 17th century. At the MPINB, our Department of Behavior and Brain Organization is working with freely moving mice to understand the neuronal mechanisms underlying vision-based decision making. Watch our video "Seeing what they see" about their new method to reconstruct the "view through the eyes" of a mouse as it detects and tracks its prey.
Furthermore, our Department of Behavior and Brain Organization recently developed a miniature microscope, small enough to be carried on the head of a freely moving mouse and capable of measuring neuronal activity in all cortical layers, even the deepest ones. Weighing only 2 grams, this microscope is extremely lightweight and its remote control minimizes the need to handle the animal. Watch our video about this game changing new miniature microscope.
The famous roundworm Caenorhabditis elegans is one of the most common model organisms used in biological research, especially in genomic research. The tiny transparent worm is easy to breed in the lab. It was the first multicellular organism to have its genome sequenced and an extensive genetic toolbox is available. It is one of the simplest organisms with a nervous system consisting of exactly 302 neurons. Still, it exhibits a wide range of behaviors. This makes it ideal to study basic principles of neural networks and the neural and molecular mechanisms that control behavior.
Our Neural Information Flow lab studies how the nervous system of C. elegans processes and filters the enormous stream of information constantly emerging from both the environment and the animal’s internal state, and how this ultimately leads to a behavioral response of the animal. Watch this video about one of the lab's latest publications.
Furthermore, our Neural Information Flow lab and our Genetics of Behavior lab work together on comparative studies on the two different worm species C. elegans and P. pacificus.
Like C. elegans, Pristionchus pacificus is a roundworm, a nematode. However, these species last shared a common ancestor about 120 million years ago. Despite this, its genome is fully sequenced and many genetic tools known from research in C. elegans also work in P. pacificus which makes P. pacifius an ideal model organism for research in evolutionary biology. Our Neural Information Flow lab and our Genetics of Behavior lab work together on comparative studies on the two different worm species.
Strikingly, P. pacificus exhibits a polymorphism in its mouth parts, meaning that two different types of mouthform exist within the species. The individual morphs can either be specialized in feeding on bacteria only, or show predatory and cannibalistic behavior feeding on other worms which is enabled by its tooth-like mouth structures. Alongside this, P. pacificus also developed the ability to recognize its own kin to spare them from ending up on its menu. Our Genetics of Behavior lab studies the molecular and cellular characteristics of this fascinating behavior and its neuronal basis in the context of evolution. Watch our interview with group leader James Lightfoot and check out the lab's own website.
With only about 12 mm body length, the freshwater fish Danionella cerebrum is among the smallest vertebrates and possesses one of the smallest known vertebrate brains. The tiny fish are used as a model organism in behavioral biology, neurobiology and developmental biology. One of the biggest advantages for research is their transparent body and the lack of a skull roof allowing us to see the brain in the living fish. Danionella cerebrum belongs to the same subfamily as zebrafish, which in turn is a very popular model organisms for genetic research. Furthermore, Danionella cerebrum possesses a rich repertoire of behaviors like courtship, schooling, and acoustic communication (male fish).
Our Department of Computational Neuroethology studies Danionella cerebrum to unravel how sensory stimuli are transformed in the brain and how neuronal networks drive decision-making and ultimately behavior. The small size of the fish's brain allows the researchers to perform behavioral studies and imaging simultaneously and to analyze the brain using electron microscopy.
The African clawed frog Xenopus tropicalisis a fully aquatic animal, but is able to migrate on land. The flattened-body frogs can grow to around 5 cm long and can be found in lowland forest and rivers in West Africa. They have been a popular model organism for developmental biology, genetics and neuroscience for decades. X. tropicalis has a unique evolutionary position which covers both mammalian and amphibian traits and is also used for comparative genetics. Unlike other Xenopus species, its genome is diploid, meaning it has two complete sets of chromosomes and therefore its genome has a structural similarity with the human genome. Thus, X. tropicalis has recently also been used as a model for human diseases and in pharmacology.
Our Department of Computational Neuroethology studies X. tropicalis to understand how the locomotor system develops during the different stages of the transition from a tadpole that moves using its tale, to a four-limbed animal. A special focus lies on the development of the spinal cord and the changes that take place in the nervous system during this transition.
Zebrafish are tropical freshwater fish native to southeast Asia. They feed on insects, zooplankton and phytoplankton. Since the 1960s, Danio rerio has been used for research and is one of the leading models in vertebrate developmental biology as its larval stage is transparent. It is widely used in genetics, neurobiology and biomedical research. Its genome is fully sequenced, it is fairly easy to genetically manipulate and 70% of human genes are also found in zebrafish. Danio rerio is used in toxicology studies, cancer research, research on neurological disorders, diabetes and much more. Different so-called transgenic strains expressing fluorescent proteins are available and offer wide possibilities for imaging. Studies also focus on the fascinating ability of the zebrafish to regenerate its heart muscle, lateral line cells and the retina. Adult zebrafish show complex behavior and studies are being performed on reward behavior, learning and memory, aggression, anxiety and sleep to unravel genetic pathways and neural circuits underlying behavior of vertebrates.
Our Department of Computational Neuroethology studies zebrafish, mostly in the larval and juvenile stages, to unravel how sensory stimuli are transformed in the brain and how neuronal networks drive decision-making and ultimately behavior in a comparative approach.