Brain stimulation device lets monkeys 'see' shapes without using eyes. The goal of this review is to begin to articulate the reasons that these research animals are a critical component of the experimental enterprise aimed at understanding the process of brain aging and to our quest to discover treatments that optimize brain and cognitive health. Other studies conducted in the rat hippocampus suggest that a neuronal change that may contribute to this is altered calcium homeostasis in older neurons (18). Age-related hearing loss, or presbycusis, is among the more commonly encountered alterations in nervous system function in older individuals. Audiometric deficits can result from various insults to the cochlea that diminish this sensory organ’s capacity to transduce acoustic information (44⇓⇓–47). Comparison of human, macaque, and mouse brains. Second, differential patterns of age-related neurovascular dysfunction between different brain regions also could bias circuits contained within a lobe to experience comparable physiological consequences associated with poorer vascular health. A strong argument can be made that, despite the measures taken, the animals did suffer during this experiment and that monkeys should never be used for experiments such as this. When contemplating the coos and screams of a fellow member of its species, the macaque uses brain regions that correspond to the two principal language centers in the human brain. As ethical debates continue to surround this work, the time has come for scientists, physicians, caretakers, and policy makers to engage in a dialogue, both among themselves and with the general public, directed toward devising the best and most humane nonhuman primate research models to achieve the common goal of optimizing cognitive health throughout life. Macaque monkeys, in particular, have been the predominant nonhuman primate model in neuroscience, although relatively recent advances in transgenic technologies for use in marmosets (99⇓–101) have rapidly established this anthropoid as a promising additional nonhuman primate tool. Importantly, the number of a specific type of interneuron expressing the neuropeptide somatostatin was positively associated with memory function in aged rats (25). This study provides a within-animal link between age-associated declines in a molecularly defined population of inhibitory cells and principal cell excitability in older hippocampal networks. May 21, 2012. 3A). A number of factors may drive the observed associations between white matter composition of specific brain regions and sensory and cognitive function during aging (90). Under this hypothesis, the efficacy of neural circuits in relatively close proximity might become similarly impacted by vascular aging. Human neuroimaging has revealed a specific network of brain regions—the default-mode network (DMN)—that reduces its activity during goal-directed behavior. This suggests that the relationships between the fractional anisotropy of hippocampus-associated white matter tracts and hearing function were not due to general changes in white matter systems across the aging brain. In this study, we applied both histone demethylase Kdm4d mRNA and histone deacetylase inhibitor trichostatin A (TSA) to the cloning of macaque monkeys. Macaque Monkey is a YouTube channel that upload everyday about MONKEY. This would be fantastic if it led to advances in the areas of insomnia and narcolepsy. Materials and Methods. *P < 0.05. Over the past several decades, neuroscientists have teased apart the various regions and networks in the brain to better understand how they contribute to normal cognitive function, but huge questions remain about consciousness and which parts of the brain can be described as the neural correlates of consciousness (NCCs)—that is, the specific brain regions that allow us to experience the smell of burnt toast, the redness of a blooming rose, or the richness of our internal thoughts. Jaan Aru, a neuroscientist at Humboldt University in Berlin, said researchers in the 1990s began to think that the thalamus was important for consciousness—a belief predicated on the fact that the thalamus is located in a central position for control and that it can change how other brain regions process information. Together, these observations indicate that auditory processing abilities functionally covary specifically with aspects of cognition driven by medial temporal lobe networks, regardless of auditory acuity. Michelle Redinbaugh, the first author of the new study and a graduate student at the University of Wisconsin-Madison, said the primary goal of the experiment was to locate NCCs in the brain. “Essentially, we were looking for increases in behaviors that you would normally see in an animal—or human—that was waking up from anesthesia.”. Interaural time differences are the primary cue used to localize lower frequency sounds, and these computations primarily involve the medial superior olivary (MSO) nucleus (74, 75). In short, Little Dog says, macaque monkeys “employ memory … Finally, another possibility is that the extent of neuronal connectivity between regions may determine the degree to which brain functions covary across the lifespan through mechanisms associated with hyperexcitability or changes in synaptic function. … “This study puts thalamus back to the picture,” Aru, who is not affiliated with the new study, told Gizmodo. Distinguishing similar, but nonidentical, experiences is a critical aspect of episodic memory that commonly becomes impaired in older individuals (16). The brain of four adult male Rhesus macaque monkeys (Macaca mulatta, M1-4) (~10–15 y old,~9 kg) were used in this study. Thursday's Best Deals: $100 Xbox Gift Card, Babeland Flash Sale, PowerA Switch Accessories, and More. When this happened, the primates behaved just as they would when awake. Insights into these basic questions are critical for devising strategies to maintain cognitive health in older individuals who fall along all points of the sensory and cognitive aging spectrum. Max Planck scientists discover brain cells in monkeys that may be linked to self-awareness and empathy in humans. Once the stimulation was turned off, the macaques returned to an unconscious state. Monkeys with greater fractional anisotropy in the fimbria-fornix (Fig. What that in mind, the new research could result in effective new therapies to treat disorders of consciousness, improved deep brain stimulation as a surgical technique, and better drugs for anesthesia. Parvalbumin-positive neuron density was not different between age groups in either region. With respect specifically to a calcium homeostasis approach, there is evidence that CaBP expression differs considerably between the auditory systems of primates and rodents. 1). wrote the paper. PRC firing rates were not different between age groups. A unique cell type – the von Economo neuron (VEN) – is located there. Regardless, there was a strong negative correlation between the density of somatostatin-positive CA3 interneurons and principal neuron firing rates (Fig. Additionally, axospinous, axosomatic, and axodendritic spine sizes appear to increase with age in the prefrontal cortex, and the extent of these structural changes in superficial cortical layers was significantly associated with performance measures on an object recognition task (36, 37). Older monkeys were impaired relative to adults on some, but not all, of the cognitive functions tested in the battery, indicating that distinct aspects of cognition operate partially independent of one another in aged macaques, as is the case in older humans (91⇓⇓⇓–95). Image credit: Shutterstock/greenbutterfly. Compared with other types of memory, episodic memory is particularly vulnerable to the effects of normative brain aging, and a hallmark of Alzheimer’s disease is a drastic reduction in the capacity to form these representations (12). We do not capture any email address. We estimate that the relative rate of neurogenesis is approximately 10 times less than that reported in the adult rodent dentate gyrus. These characteristics allow different aspects of brain function to be tested with similar or even identical tests as those used in humans. (E) CA3 SOM neuron density and CA3 firing rates showed weak associations with object recognition performance. Although in macaque monkeys the rubrospinal tract is an important contributor to recovery, it is unclear how far this can be extended to humans, where the rubrospinal projection is thought to be very weak (Nathan and Smith, 1955; Onodera and Hicks, 2010). The calcium hypothesis of brain aging posits that excess intracellular calcium levels in aging hippocampal cells result in altered cellular metabolism, gene expression, and neurotransmitter release that may ultimately result in mnemonic impairment (18, 23, 24). Additionally, the shape and organization of the other olivary nuclei are very different in the rat compared with monkeys and humans. (E) Frontal radiation FA was not associated with auditory processing. This work was supported by NIH Grants R01 AG050548 (to C.A.B.) This might be achieved either by finding a means to abolish hyperexcitability or by enhancing built-in cellular mechanisms that aged auditory neurons appear to employ to help maintain a healthier intracellular state in the face of pathophysiology elsewhere in the system. The June 2018 release is out. 2E). Reprinted with permission from refs. Since most CaBPs operate as intracellular calcium buffers (67), the greater expression of these proteins in the auditory system of older animals has been proposed to reflect cellular response mechanisms to the potentially pathophysiological environment associated with greater calcium levels. 5 D–F) or anterior commissure. Both of these points emphasize how nonhuman primates can provide a fundamental link between nonprimate laboratory animals and humans. Furthermore, these electrophysiological changes were significantly associated with performance on an object recognition task (41). In particular, the human audiogram to 60-dB tone stimuli ranges roughly from 31 Hz to 17.6 kHz, and macaques show an acoustic range between 28 Hz and 34.5 kHz when given tones of the same intensity (71). Shapeshifting designs could have wide-ranging pharmaceutical and biomedical applications in coming years. For example, inhibitory interneurons destined for the frontal lobes are enriched with different combinations of transcription factors during development than those destined for the temporal lobes (97). Lesion and functional imaging studies in humans indicate that the integrity of medial temporal lobe brain structures, including the hippocampus, is critical for episodic memory formation (13, 14). (A) Images of the dorsal surface of a human brain, macaque brain, and mouse brain. There will be a particular emphasis on conceptualizing the critical bridge that nonhuman primates provide between behavioral, neuroanatomical, and electrophysiological data obtained in aged rodents and cognitive, psychophysical, and functional imaging data from older humans. and by the McKnight Brain Research Foundation. Notice the striking differences in the size and convolution complexity of the cerebral cortex across the 3 species. Source memory in older adults: An encoding or retrieval problem? New research suggests monkeys, like this Japanese macaque, have vocal tracts anatomically capable of humanlike speech, but they lack the necessary brain wiring to produce it. Sensory functioning and intelligence in old age: A strong connection, The strong connection between sensory and cognitive performance in old age: Not due to sensory acuity reductions operating during cognitive assessment. Older monkeys showed drastic auditory processing deficits relative to adults despite auditory thresholds and visual system function not being different between age groups. Studies using electrophysiological and neuroanatomical techniques in aging rats have provided a critical, yet incomplete, window into the neurobiological processes that might result in CA3/dentate gyrus hyperactivity in older people. Anatomical studies in aging macaques have provided substantial evidence that the total number of neurons in the prefrontal cortex (28⇓–30) and medial temporal lobe (31⇓–33) does not change across the lifespan in the absence of neurodegenerative disease. Research aimed at uncovering therapeutic approaches to alleviate the impact of presbycusis necessitates an animal model with an auditory system that anatomically and functionally approximates that of humans as closely as is possible. Adapted by permission from ref. The same monkeys underwent electrophysiological assessments of auditory thresholds, auditory system temporal information processing, and visual system temporal information processing. As a result, histological experiments aimed at quantifying the number of neurons expressing calcium binding proteins (CaBPs) were conducted throughout the central auditory system. More recently, the impact that hearing loss, in particular, has on cognition has reemerged as a topic of research interest. Furthermore, cognitive and sensory brain structures in nonhuman primates share many more organizational principles with human brains than do the brains of phylogenetically more distant laboratory animals such as rodents (7⇓⇓⇓–11) (Fig. Using genetically encoded indicators including GCaMP5 and GCaMP6s delivered by Diffusion tensor imaging analyses of frontal cortex- and medial temporal lobe-associated white matter microstructural condition were performed in the same monkeys to determine whether sensory and cognitive processing abilities are associated with the structural composition of these cognitive circuits. The brains from these animals were then harvested and serially sectioned for immunohistochemical labeling of 2 chemically distinct classes of inhibitory cells: somatostatin-positive and parvalbumin-positive interneurons. The brains of the monkeys are considered a delicacy, and they are thought to be a cure for impotence. CRISPR-Cas9 gene editing can improve the effectiveness of spermatogonial stem cell transplantation in mice and livestock, a study finds. Amanda Rodewald, Ivan Rudik, and Catherine Kling talk about the hazards of ozone pollution to birds. This similarity in cortical function between humans and old-world monkeys suggests that brain networks supporting volitional communication have a common evolutionary origin that arose well prior to the hominin radiation. Non-human primates like the macaque are able to communicate about such things as food, identity or danger with vocalizations that are interpreted by others of their species and acted upon. Adult and aged monkeys underwent a test of object recognition memory. NAS colloquia began in 1991 and have been published in PNAS since 1995. and F31 AG055263 (to D.T.G.) Critically, rodents do not appear to have these chemically defined parallel auditory pathways since the auditory thalamus of rats is almost completely devoid of parvalbumin and lacks calbindin in many areas where it is clearly expressed in primates (69, 70). During the experiments, for example, a clinical anesthesiologist was to present to make sure the monkeys “received the same level of care as human patients in the hospital,” said Redinbaugh, and the animals were monitored both during and after the experiments to “ensure their health and wellbeing,” among other measures, she said. The acquisition of multiple estimates of cognitive and sensory function within the same group of monkeys allowed an assessment of whether specific cognitive and sensory domains changed independent of one another or in tandem (90). It seems like the definition of inhumanity, … had higher auditory processing and higher overall cognition mysterious in. 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