The Mouse Transplant Experiments
As part of the research leading to the isolation of human brain stem cells, Weissman, Uchida and other colleagues at the firm StemCells Inc. began transplanting human brain stem cells into the brains of SCID mice with normal murine brains. The human brain stem cells were placed in a brain structure called the lateral ventricle, which, in mice, connects to their brains quite large olfactory bulbs. Weissmans group was able to show that the human neuronal stem cells engrafted in a brain stem cell niche called the subventricular zone, near the injections. Those cells also migrated to a second niche, the dentate gyrus of the hippocampus. In these niches the human cells divided and many of them migrated toward the olfactory bulb . Samples of the brains of these mice showed that the human neurons had survived and had connected to the mouse brain. Mouse brains have a much larger olfactory bulb than human brains and new mouse neurons are regularly migrating to their olfactory bulbs; the human-derived cells did the same. Examination also showed that the human neurons had moved into other areas of the murine brains and made up more than 1% of the neurons in some regions. This research could not, however, determine whether the human neurons were actually functioning as part of the mouse brain, let alone whether they were functioning normally.
Medical Progress Through Primate Research
As laboratory animals, monkeys have already provided important findings for medicine. The rhesus factor incompatibility in a mother’s blood and in the blood of her unborn children was discovered as a result of studies conducted on rhesus macaques, hence the name. The vaccinations that prevent polio, measles, yellow fever and Hepatitis B are all based on research that was carried out on monkeys. The treatment of diabetes patients with insulin was researched on monkeys, as was the treatment of patients with leprosy and rheumatoid arthritis. The development of stem cell technology, on which so many hopes are based today, can also be traced back to work with monkeys.
Deep brain stimulation for Parkinson’s patients
Research has been ongoing for some time now on a new method in which the spinal cord rather than the brain is stimulated with electrodes. These studies are currently taking place on rats. However, before the results can be transferred to humans, they must be researched on monkeys.
Primates used as a model in dementia research
Primates used as a model in Huntington’s disease
Brain-machine interfaces for patients with locked-in syndrome
Brain-machine interfaces in paraplegia
What Do The Results Of The Study Mean For Chronic Yawners
First and foremost, the study shows that it is not negative to yawn a lot. It is a normal function of the body that ensures the proper functioning of the brain. The stereotype that people that yawn during a conversation are bored or not interested in the conversation is false. In contrast, the study suggests that people yawn to keep their brains in working order, which is quite important during a conversation.
Facebook/LinkedIn image: leungchopan/Shutterstock
Massen, J.J.M., Hartlieb, M., Martin, J.S. et al. Brain size and neuron numbers drive differences in yawn duration across mammals and birds. Commun Biol 4, 503 .
Altered Levels Of Consciousness In Humans
The study of altered levels of consciousness such as coma or anesthesia has provided clinical, ethical and even legal motivations for the neuroscientific study of consciousness .1). A better understanding of the links between consciousness and the brain is indeed required to better characterize neural markers of consciousness in these states . An improved understanding could also facilitate new treatments for severely brain-damaged patients . Finally, the issue of awareness under anesthesia merits greater scrutiny, particularly given the evidence that such episodes may commonly be missed by applying the various techniques currently used to monitor brain function under sedation .
Level and contents of consciousness. The level of consciousness can be dissociated from behaviors that are traditionally regarded as a signs of vigilance or arousal . Typically, high conscious levels are associated with an increased range of conscious contents. Whether or not high level of consciousness without any conscious contents is possible remains unclear. Adapted from Laureys , courtesy of Giulio Tononi.
Recent advances in functional imaging and electrophysiological techniques applied in these contexts have significantly expanded our knowledge of neural correlates of conscious level in humans. Accordingly, some outstanding advances in this field are summarized below.
Severe brain damaged patients: coma, vegetative state , and minimally conscious states
Strongest Evidence Of Animal Culture Seen In Monkeys And Whales
Until fairly recently, many scientists thought that only humans had culture, but that idea is now being crushed by an avalanche of recent research with animals. Two new studies in monkeys and whales take the work further, showing how new cultural traditions can be formed and how conformity might help a species survive and prosper. The findings may also help researchers distinguish the differences between animal and human cultures.
Researchers differ on exactly how to define culture, but most agree that it involves a collective adoption and transmission of one or more behaviors among a group. Humans’ ability to create and transmit new cultural trends has helped our species dominate Earth, in large part because each new generation can benefit from the experiences of the previous one. Researchers have found that similar, albeit much simpler, cultural transmission takes place in animals, including fish, insects, meerkats, birds, monkeys, and apes. Sometimes these cultural traits seem bizarre, such as the recently developed trend among some capuchin monkeys to poke each other’s eyeballs with their long, sharp fingernailsa behavior that originated among a small group of individuals and which has spread over time.
The whale study also gets a thumbs up. It’s “an amazing compilation of data,” says Susan Perry, an anthropologist at the University of California, Los Angeles. “I find this to be a highly convincing case for a foraging tradition in a cetacean.”
Aborted Fetuses As The Source Of The Human Brain Stem Cells
The human brain stem cells that Weissman uses were derived from the brains of human fetuses that had been intentionally aborted. Use of such tissue has been controversial in the United States because of its link to voluntary abortion. The issue of using human fetal tissue in research and medicine was discussed widely in the late 1980s, spurred in part by evidence that transplants of fetal brain tissue into the brains of people with Parkinsons disease could lead to improvement in their condition. For research and medical purposes, tissues from intentionally aborted fetuses were greatly preferred to tissues from spontaneous abortions or stillbirths because of the much greater risk that the cells and tissues from the latter had suffered from fatal genetic conditions, had been contaminated by pathogens, or had died in the long period between the in utero death of the fetus and the collection of the tissues.
Relevance To Ongoing Debates In The False Memory Literature
That laboratory animals, whose learning histories and experiences are fully known and controlled, also create false memories may help alleviate the long-standing concern expressed by some critics that human false memory studies may simply have been extracting true autobiographical memories rather than implanting false ones . Although false memory researchers went to great lengths to ensure that the memories they attempted to implant were highly unlikely to have been experienced by their participants lingering doubts remained, and that possibility could never be entirely ruled out. An advantage of false memories in lower animals is that they cannot be explained by such a mechanism.
Why Do Researcher Investigate Primates
Monkeys are used in animal research only if a particular phenomenon cannot be studied on any other species of animal, such as mice, fish or fruit flies. In the course of evolution, similar structures and functional principles have developed in the brains of monkeys and humans. Such structures and principles are not present in other mammal groups. Neuroscientists can therefore only research complex cognitive functions relating to perception, attention, memory formation and awareness on monkeys.
Because they are biologically so similar to humans, the potential for applying research results to humans is very high. They are therefore used primarily for the final drug safety tests on new medicines before they are used on humans. Moreover, scientists use monkeys to study important fundamental questions on how a healthy organism functions or how to cure fatal illnesses or severely debilitating disorders . Monkeys therefore play an important role as laboratory animals in infection research and in the neurosciences.
Phase 3: Interactive Studies
Pilot: November 2021
Deployed: Winter 2022
Based heavily on the insights gained in phases 1 and 2, we will be piloting direct, controlled tests of learner sound button use and understanding that aim to determine how language-like learners’ sound button use is. We anticipate that these will be done with a smaller number of participants.
Psychology Research: Psychological Research On Animals
Psychological research aims to understand human behavior and how the mind works. This involves studying non-human animals for research through observation as well as experiments.
Some of the experimental procedures involve electric shocks, drug injections, food deprivation, maternal separation, and manipulating brain functions to determine the effects on sensory and cognitive abilities as well as behavior . Non-human primates, cats, dogs, rabbits, rats and other rodents are most commonly used in psychological experiments, though animals are also used for teaching within psychology, as well as behavior therapy for treating phobias.
In the past, there have been a number of psychological experiments using animals to test various hypotheses. Psychologist, Dr. Harlow experimented on monkeys to show effects of social isolation; Skinner worked with pigeons to study superstition, while Pavlov used dogs to investigate operant conditioning. However, there is a lot of debate on the use of non-human animals in psychological research and many ethical issues both in favor and against it.
The Working Group And Its Approach
Weissman was aware of the sensitivity of these planned experiments, both ethically and in terms of public reaction. He may well have had visions of a headline reading Stanford Scientist Creates Mouse with Human Brain. As a result he asked one of the authors of this article to consider putting together a group to examine the ethical issues in these proposed experiments. Greely pulled together this ad hoc group, with representation from several disciplines. We met several times during 2000 and 2001, interviewed Weiss-man, studied the scientific literature, and discussed the questionsand how we could approach those questionsat length. We concluded that the experiments did raise interesting and important, but manageable, ethical issues
In general, we approached the questions by asking about the potential benefits and the potential costs or risks of the proposed experiments. We first examined the costs to see if any of them might categorically rule out the experiments. We next considered ways in which the experiments might be undertaken to limit the costs of risks involved. We weighed the potential benefits of the research, with or without modifying conditions, against the potential costs or risks. We concluded that the experiments could proceed ethically, subject to careful staging and monitoring.
Desire: The Neural Systems Of Reward Seeking
One of the most important affective neuronal systems relates to feelings of desire, or the appetite for rewards. Researchers refer to these appetitive processes using terms such as wanting , seeking , or behavioural activation sensitivity . When the appetitive system is aroused, the organism shows enthusiasm, interest, and curiosity. These neural circuits motivate the animal to move through its environment in search of rewards such as appetizing foods, attractive sex partners, and other pleasurable stimuli. When the appetitive system is underaroused, the organism appears depressed and helpless.
Much evidence for the structures involved in this system comes from animal research using direct brain stimulation. When an electrode is implanted in the lateral hypothalamus or in cortical or mesencephalic regions to which the hypothalamus is connected, animals will press a lever to deliver electrical stimulation, suggesting that they find the stimulation pleasurable. The regions in the desire system also include the amygdala, nucleus accumbens, and frontal cortex . The neurotransmitter dopamine, produced in the mesolimbic and mesocortical dopamine circuits, activates these regions. It creates a sense of excitement, meaningfulness, and anticipation. These structures are also sensitive to drugs such as cocaine and amphetamines, chemicals that have similar effects to dopamine .
University Of California Riverside
On April 21, 1985, activists of the Animal Liberation Front broke into the UC Riverside laboratories and removed hundreds of animals. According to Vicky Miller of PETA, who reported the raid to newswire services, UC-Riverside “has been using animals in experiments on sight deprivation and isolation for the last two years and has recently received a grant, paid for with our tax dollars, to continue torturing and killing animals.” According to UCR officials, the ALF claims of animal mistreatment were “absolutely false,” and the raid would result in long-term damage to some of the research projects, including those aimed at developing devices and treatment for blindness. UCR officials also reported the raid also included smashing equipment and resulted in several hundred thousand dollars of damage.
In Germany in 2004, journalist Friedrich MÃ¼lln took undercover footage of staff in Covance in MÃ¼nster, Europe’s largest primate-testing center. Staff were filmed handling monkeys roughly, screaming at them, and making them dance to blaring music. The monkeys were shown isolated in small wire cages with little or no natural light, no environmental enrichment, and subjected to high noise levels from staff shouting and playing the radio. PrimatologistJane Goodall described their living conditions as “horrendous.”
The Importance Of Research With Nonhuman Animals
APA is a leader in supporting ethical research that enhances the lives of humans and nonhumans alike
October 2017, Vol 48, No. 9
Print version: page 6
Monitor on Psychology48
As a neuropsychologist, I have a keen appreciation for the contributions of basic research with nonhuman animals to our understanding of the brain and behavior. Such work is not only central to basic research in experimental psychology, behavioral neuroscience and psychopharmacology, but has also led to important applications in a wide range of fields including clinical psychology , pediatrics , rehabilitation , human factors and, of course, clinical neuropsychology .
Psychologists and APA have long been interested in the well-being of research animals. The precursor to APA’s current was established in 1925. CARE’s mission includes safeguarding responsible research with nonhuman animals, disseminating accurate information about such research, reviewing the ethics of such research and recommending guidelines for its ethical conduct, and protecting the welfare of nonhuman animals in research, teaching and practical applications.
Chimpanzees In The United States
As of 2013, the U.S. and Gabon were the only countries that still allowed chimpanzees to be used for medical experiments. The U.S. is the world’s largest user of chimpanzees for biomedical research, with approximately 1,200 individual subjects in U.S. labs as of middle 2011, dropping to less than 700 as of 2016. Japan also still keeps a dozen chimpanzees in a research project for chimpanzee cognition ” rel=”nofollow”>Ai ).
Chimpanzees routinely live 30 years in captivity, and can reach 60 years of age.
Most of the labs either conduct or make the chimpanzees available for invasive research, defined as “inoculation with an infectious agent, surgery or biopsy conducted for the sake of research and not for the sake of the chimpanzee, and/or drug testing.” Two federally funded laboratories have used chimps: Yerkes National Primate Research Center at Emory University in Atlanta, Georgia, and the Southwest National Primate Research Center in San Antonio, Texas. By 2008, five hundred chimps had been retired from laboratory use in the U.S. and live in sanctuaries in the U.S. or Canada.
In January 2014, Merck & Co. announced that the company will not use chimpanzees for research, joining over 20 pharmaceutical companies and contract laboratories that have made the commitment. As the trend continues, it is estimated the remaining non-government owned 1,000 chimpanzees will be retired to sanctuaries around 2020.
Animal Neuropsychology Paved The Way
Neuropsychological research on animals is of interest to our discussion of consciousness, not because it necessarily revealed anything about consciousness per se. The work was instead important because it provided a neuroanatomical and conceptual foundation that guided the design and interpretation of studies of human patients.
The most important institute for neuropsychological research on animals in the 1940s was the Yerkes Primate Center in Florida, which was directed by Lashley. Researchers there were trained in the Franz/Lashley approach and used specific behavioral tasks to test specific brain functions. When the neurosurgeon Karl Pribram took over the directorship at Yerkes shortly after the end of World War II, he continued the behavioral approach established by Lashley but with added neurosurgical sophistication. The field of animal neuropsychology flourished during Pribrams decade-long rein at Yerkes. Young researchers who would come to be the face of the field cut their scientific teeth at Yerkes under Pribrams guidance.
Only a few examples of the output and implications of research done at the Yerkes laboratory in the 1950s were mentioned here, but it would be hard to overstate the importance of this group. These researchers paved the way for much future work on the brain mechanisms of perception, memory, emotion, and higher cognition, and also of consciousness.
Contents Of Consciousness In Humans
Definitions and measures for contents of consciousness
Studies of neural correlates of consciousness in HAVs often target neural correlates of conscious contents, while the level of consciousness is assumed to be constant. Classically, measures of conscious perception in awake humans distinguish objective performance, such as the ability to discriminate the presence, absence, or identity of distinct stimuli, from subjective reports, such as subjective ratings of the visibility of stimuli or confidence ratings of the accuracy of perceptual decisions, which are associated with conscious perception. Studies taking this approach have benefited from the application of âsignal detection theoryâ , which provides robust methods for distinguishing objective performance from subjective performance , independently of response biases. While subjective ratings are typically obtained by asking subjects to rate their confidence in their responses, several alternatives exist . Currently there is no consensus about a single best approach, and different measures show empirical as well as theoretical divergence .
Neuroimaging studies of the neural correlates of consciousness of conscious contents
Over the last decades, many studies have investigated NCCs of conscious contents in HAVs. A common paradigm is to employ functional neuroimaging experiments contrasting brain responses to intensity-matched perceived and unperceived stimuli.
What Are The Issues Raised
This project might conjure images of mad scientists meddling with nature, irresponsible and without oversight. But unlike Frankensteins experiments, this study was not done in secret.
In the paper, the researchers describe in detail the steps they took to comply with international guidelines. This included extensive ethics reviews undertaken within the institutions involved and consultation with external bioethicists.
Of note, the study involved the use of eggs harvested from female monkeys. While the animals werent killed, any use of non-human primates should be approached conservatively and be consistent with international standards.
Research involving non-human primates is carefully scrutinised. Such projects receive special consideration from regulatory bodies and ethics committees around the world.
Nonetheless, even when conducted with ample oversight, human-animal chimera research does raise ethical questions.
The thorniest ones are linked not to the creation of in-vitro chimeric embryos, but rather the eventual creation of live-born chimeras, such as a human-pig chimera, if future research can overcome current limitations.
The Brain Cooling Hypothesis Of Yawning
A new study, just published in the scientific journal Communications Biology , now was aimed at testing a fascinating hypothesis on why we yawn: The brain cooling hypothesis. This hypothesis suggests that the reason why we yawn is to cool the brain. According to the brain cooling hypothesis, the purpose of the muscular contractions and the deep inhalation during yawing is to flush away hotter blood from the head and replacing it with cooler blood. Cooling the brain is important as too much heat from the activity of the nerve cells and the surrounding temperature may impair brain function due to overheating.
How Should We Manage These Concerns
Like many other aspects of stem cell research, we can find a starting point in guidelines from the International Society for Stem Cell Research.
These standards, soon to be updated, explicitly recommend specialised review for human-animal chimera research. This includes monitoring chimeric animals for unexpected behaviours that indicate suffering, which could then be addressed under existing animal ethics principles.
Experts it might be worth monitoring chimeric animals for evidence they may be autonomous, rational, or self-aware and modifying their treatment accordingly.
Given the ethical complexity and sensitivity of human-animal chimera research, its crucial it receives careful oversight. As the field develops we must continuously review where the boundaries of the research lie.
And these conversations must not only explore animal welfare, but also how potential patients and the broader community view access to organs derived from donor animals.
Megan Munsie is deputy Director at the Centre for Stem Cell Systems, and head of engagements, Ethics & Policy Program, Stem Cells Australia at The University of Melbourne and Julian Koplin is a resarch fellow in Biomedical Ethics at Melbourne Law School and Murdoch Children’s Research Institute.
An Instinct For Numbers
Although researchers once thought that humans were the only species with a sense of quantity, studies since the mid-twentieth century have revealed that many animals share the ability. For instance, fish, bees and newborn chicks can instantly recognize quantities up to four, a skill known as subitizing. Some animals are also capable of large-quantity discrimination: they can appreciate the difference between two large quantities if they are distinct enough. Creatures with this skill could, for example, distinguish 10 objects from 20 objects, but not 20 from 21. Six-month-old human infants also show a similar appreciation of quantity, even before they have had significant exposure to human culture or language.
What all of this suggests, says Andreas Nieder, a neuroscientist at the University of Tübingen, Germany, is that humans have an innate appreciation of numbers. That arose through evolutionary processes such as natural selection, he says, because it would have carried adaptive benefits.
An idea called material engagement theory suggests that the mental concept of numbers extends to physical objects, such as fingers.Credit: Matthew Horwood/Getty
Background To The Working Group Report
When the original report was written for Dr. Weissman, researchers had recently reported finding human brain stem cellscells that can become all or most of the cell types found in the human brain, including neurons and glial cells. These cells, thought to be very infrequent in adults, were isolated from the brains of human fetuses. This discovery opened the possibility of studying human neurons in vivo in laboratory animals by creating mice whose brains were made up, in part or in whole, of human neurons.
Although such a human neuron mouse would not stand and talk like a cartoon character, its possible creation raises important and interesting ethical questions about research in human neuroscience. The next section lays the groundwork for evaluating these issues by discussing human brain stem cells, examining completed and planned experiments involving transplantation of these cells into mice, and finally by describing our working group and its general approach to the questions before it.
The Foundations Of Consciousness Research In The Late 19th And Early 20th Centuries
Although our emphasis will be on the mid-20th century, this period must be contextualized by the fact that research on brain and consciousness, like many other topics in psychology and brain science, began in the late 19th century. This was a time when psychological questions were driven by philosophical understanding of the mind, which was often equated with consciousness. As a result, research on brain and behavior naturally considered the role of consciousness in behavioral control by the brain.
As is still common today, these early researchers explored the effects of surgical ablation or electrical stimulation of brain areas . Several studies demonstrated that decorticated animals could exhibit high degrees of behavioral flexibility . These observations led to a debate as to whether the behavioral responses of decorticated animals were driven by unconscious sensitivity or conscious sensations, and whether having a cerebral cortex was necessary for having conscious experiences .
Ferrier felt that it was essential to study consciousness in humans, warning that researchers cannot rely on behavioral appearances alone in animals: the plaintive cry elicited by pinching the foot of a rabbit may be merely a reflex phenomenon, not depending on any true sense of pain . By contrast, studies of humans can use verbal reports to assess consciousness of impressions .