Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Social and Behavioral Sciences (926)
- Psychology (596)
- Animal Studies (525)
- Zoology (444)
- Ecology and Evolutionary Biology (432)
-
- Arts and Humanities (412)
- Philosophy (411)
- Other Animal Sciences (408)
- Evolution (396)
- Ethics and Political Philosophy (377)
- Cognition and Perception (373)
- Terrestrial and Aquatic Ecology (359)
- Philosophy of Mind (348)
- Neuroscience and Neurobiology (342)
- Cognitive Neuroscience (337)
- Comparative Psychology (224)
- Medicine and Health Sciences (121)
- Veterinary Medicine (83)
- Anthropology (78)
- Other Anthropology (75)
- Agribusiness (37)
- Business (37)
- Dairy Science (35)
- Veterinary Physiology (28)
- Anatomy (22)
- Operations and Supply Chain Management (21)
- Animal Structures (20)
- Aquaculture and Fisheries (19)
- Keyword
-
- Animal welfare (51)
- Sentience (49)
- Consciousness (41)
- Pain (40)
- Welfare (38)
-
- Cognition (36)
- Fish (35)
- Evolution (22)
- Emotions (21)
- Nociception (21)
- Animal cognition (17)
- Behavior (17)
- Ethics (17)
- Dogs (16)
- Social cognition (16)
- Personality (14)
- Stress (14)
- Intelligence (13)
- Emotion (12)
- Animal ethics (11)
- Behaviour (11)
- Dog (11)
- Sheep (11)
- Animal sentience (10)
- Brain (10)
- Cortisol (10)
- Suffering (10)
- Vocal communication (10)
- Aggression (9)
- Boldness (9)
- Publication Year
- Publication
-
- Animal Sentience (454)
- Sentience Collection (129)
- Close Up Reports (52)
- Veterinary Science and Medicine Collection (36)
- International Journal for the Study of Animal Problems (34)
-
- Physiology Collection (17)
- Aquaculture Collection (16)
- Assessment of Animal Welfare Collection (16)
- Ethology Collection (15)
- Housing and Confinement of Farm Animals Collection (15)
- Social Cognition Collection (15)
- Bioacoustics Collection (11)
- Genetics Collection (11)
- Epidemiology Collection (10)
- Communication Skills Collection (9)
- Biochemistry Collection (7)
- Experimentation Collection (7)
- Ontogeny Collection (7)
- eBooks (7)
- Endocrinology Collection (6)
- Farm Animal Welfare Collection (5)
- Aquaculture and Fisheries Collection (4)
- Emotion Collection (4)
- Farm Animal Husbandry Collection (4)
- Learning Ability Collection (4)
- Agribusiness Collection (3)
- Animal Welfare Collection (3)
- Evolutionary Biology Collection (3)
- Intelligence Collection (3)
- Nutrition Collection (3)
- Publication Type
Articles 751 - 780 of 990
Full-Text Articles in Animal Sciences
Using Self-Organizing Maps To Recognize Acoustic Units Associated With Information Content In Animal Vocalizations, John Placer, C. N. Slobodchikoff, Jason Burns, Jeffrey Placer, Ryan Middleton
Using Self-Organizing Maps To Recognize Acoustic Units Associated With Information Content In Animal Vocalizations, John Placer, C. N. Slobodchikoff, Jason Burns, Jeffrey Placer, Ryan Middleton
Veterinary Science and Medicine Collection
Kohonen self-organizing neural networks, also called self-organizing maps (SOMs), have been used successfully to recognize human phonemes and in this way to aid in human speech recognition. This paper describes how SOMS also can be used to associate specific information content with animal vocalizations. A SOM was used to identify acoustic units in Gunnison’s prairie dog alarm calls that were vocalized in the presence of three different predator species. Some of these acoustic units and their combinations were found exclusively in the alarm calls associated with a particular predator species and were used to associate predator species information with individual …
Acoustic Structures In The Alarm Calls Of Gunnison’S Prairie Dogs, C. N. Slobodchikoff, J. Placer
Acoustic Structures In The Alarm Calls Of Gunnison’S Prairie Dogs, C. N. Slobodchikoff, J. Placer
Veterinary Science and Medicine Collection
Acoustic structures of sound in Gunnison’s prairie dog alarm calls are described, showing how these acoustic structures may encode information about three different predator species (red-tailed hawk—Buteo jamaicensis; domestic dog—Canis familaris; and coyote—Canis latrans). By dividing each alarm call into 25 equal-sized partitions and using resonant frequencies within each partition, commonly occurring acoustic structures were identified as components of alarm calls for the three predators. Although most of the acoustic structures appeared in alarm calls elicited by all three predator species, the frequency of occurrence of these acoustic structures varied among the alarm calls for the different predators, suggesting that …
Grey Parrot (Psittacus Erithacus) Numerical Abilities: Addition And Further Experiments On A Zero-Like Concept, Irene M. Pepperberg
Grey Parrot (Psittacus Erithacus) Numerical Abilities: Addition And Further Experiments On A Zero-Like Concept, Irene M. Pepperberg
Sentience Collection
A Grey parrot (Psittacus erithacus), able to quantify 6 or fewer item sets (including heterogeneous subsets) by using English labels (I. M. Pepperberg, 1994), was tested on addition of quantities involving 0–6. He was, without explicit training, asked, “How many total X?” for 2 sequentially presented collections (e.g., of variously sized jelly beans or nuts) and required to answer with a vocal English number label. His accuracy suggested (a) that his addition abilities are comparable to those of nonhuman primates and young children, (b) some limits as to his correlation of “none” and the concept of zero, and (c) a …
Ethics And Welfare: Pain Perception In Fish, L. U. Sneddon
Ethics And Welfare: Pain Perception In Fish, L. U. Sneddon
Aquaculture Collection
Fish welfare is currently a controversial subject with many scientific studies now demonstrating the possibility for fish to experience negative events such as pain, fear and stress. This has important implications in the treatment of fish during commercial and experimental procedures in terms of ethics and welfare. In this review, the evidence for pain perception in fish is considered and the repercussions for the use of fish as a research model as well as in aquaculture and largescale fisheries. These issues are discussed briefly from a welfare and ethical perspective.
Exploration And Habituation In Intact Free Moving Octopus Vulgaris, Jennifer Mather
Exploration And Habituation In Intact Free Moving Octopus Vulgaris, Jennifer Mather
Sentience Collection
Despite the huge numbers of studies published on the learning of cephalopod mollusks, studies on non-associative learning are scarce. We tested non-associative learning (habituation) and exploration in Octopus vulgaris in two different studies using a prey-shaped object (Study A) and inanimate objects and food objects (Study B). Study A consisted of the repeated presentation of a prey-like stimulus, which 23 subjects could only explore visually. In study B, 14 octopuses were presented two Lego blocks (one black and white with a smooth surface, one a blue "snowflake" with a rough surface) and two food items, one preferred (clams) and one …
Differential Effects Of Sodium And Magnesium Sulfate On Water Consumption By Beef Cattle, A. S. Grout, D. M. Veira, D. M. Weary, M. A. G. Von Keyserlingk, D. Fraser
Differential Effects Of Sodium And Magnesium Sulfate On Water Consumption By Beef Cattle, A. S. Grout, D. M. Veira, D. M. Weary, M. A. G. Von Keyserlingk, D. Fraser
Biochemistry Collection
The existing guidelines for maximum sulfate (SO4) in cattle drinking water are based on Na2SO4, although many water sources contain greater concentrations of MgSO4. Two experiments compared the effect of different SO4 salts on water consumption and fecal DM of cattle. In Exp. 1, 8 yearling heifers (initial BW = 345 ± 8 kg; mean ± SD) were watered twice daily with tapwater or water containing Na2SO4 or MgSO4 at target levels of 1,500, 3,000, or 4,500 mg of SO4/L for 2-d treatment periods separated by 2 …
Chimpanzee Theory Of Mind: Looking In All The Wrong Places?, Kristin Andrews
Chimpanzee Theory Of Mind: Looking In All The Wrong Places?, Kristin Andrews
Sentience Collection
I respond to an argument presented by Daniel Povinelli and Jennifer Vonk that the current generation of experiments on chimpanzee theory of mind cannot decide whether chimpanzees have the ability to reason about mental states. I argue that Povinelli and Vonk’s proposed experiment is subject to their own criticisms and that there should be a more radical shift away from experiments that ask subjects to predict behavior. Further, I argue that Povinelli and Vonk’s theoretical commitments should lead them to accept this new approach, and that experiments which offer subjects the opportunity to look for explanations for anomalous behavior should …
Cortical Complexity In Cetacean Brains, Patrick R. Hof, Rebecca Chanis, Lori Marino
Cortical Complexity In Cetacean Brains, Patrick R. Hof, Rebecca Chanis, Lori Marino
Veterinary Science and Medicine Collection
Cetaceans (dolphins, whales, and porpoises) have a long, dramatically divergent evolutionary history compared with terrestrial mammals. Throughout their 55–60 million years of evolution, cetaceans acquired a compelling set of characteristics that include echolocation ability (in odontocetes), complex auditory and communicative capacities, and complex social organization. Moreover, although cetaceans have not shared a common ancestor with primates for over 90 million years, they possess a set of cognitive attributes that are strikingly convergent with those of many primates, including great apes and humans. In contrast, cetaceans have evolved a highly unusual combination of neurobiological features different from that of primates. As …
In Situ Examination Of Boldness–Shyness Traits In The Tropical Poeciliid, Brachyraphis Episcopi, Culum Brown, Felicity Jones, Victoria Braithwaite
In Situ Examination Of Boldness–Shyness Traits In The Tropical Poeciliid, Brachyraphis Episcopi, Culum Brown, Felicity Jones, Victoria Braithwaite
Sentience Collection
Explaining consistent variation in the behaviour of individuals in terms of personality differences is one of the cornerstones of understanding human behaviour but is seldom discussed in behavioural ecology for fear of invoking anthropomorphism. Recently, however, interest has begun to focus on identifying personality traits in animals and examining their possible evolutionary consequences. One major axis used to define personality traits is the shyness–boldness continuum. We examined boldness in an in situ experiment using fish from eight populations of the poeciliid Brachyraphis episcopi (also referred to as Brachyrhaphis episcopi). Fish from high- and low-predation regions within four streams that run …
The Use Of Transcriptomics To Address Questions In Behaviour: Production Of A Suppression Subtractive Hybridisation Library From Dominance Hierarchies Of Rainbow Trout, Lynne U. Sneddon, Javier Margareto, Andrew R. Cossins
The Use Of Transcriptomics To Address Questions In Behaviour: Production Of A Suppression Subtractive Hybridisation Library From Dominance Hierarchies Of Rainbow Trout, Lynne U. Sneddon, Javier Margareto, Andrew R. Cossins
Ethology Collection
Microarrays, or gene chips, are transforming the way that gene expression is measured by allowing us to determine the expression of thousands of genes from a sample. This gives immense power to examine gene expression on a global scale within individual animals and between animals. The scope for analysing complex animal functions at the molecular level is within our grasp. Relatively few studies have examined complex behaviours and correlated them with gene expression in the central nervous system. Here, we review the use of microarray technology in the dissection of behaviour and focus specifically on dominance status. A cDNA library …
Influence Of Neck-Rail Placement On Free-Stall Preference, Use, And Cleanliness, Cassandra B. Tucker, Daniel M. Weary, David Fraser
Influence Of Neck-Rail Placement On Free-Stall Preference, Use, And Cleanliness, Cassandra B. Tucker, Daniel M. Weary, David Fraser
Housing and Confinement of Farm Animals Collection
Three experiments examined how the presence of a neck rail at different heights and locations influenced dairy cattle behavior and stall cleanliness. Experiment 1 compared 4 levels of neck-rail height (102, 114, and 127 cm and no neck rail; presented at 160 or 180 cm from the curb) in a preference test. Cows (n = 10) showed no consistent preference based on neck-rail height, regardless of the horizontal position of the neck rail. When cows were restricted to each treatment in turn, however, time spent standing fully (with all 4 hooves) in the stall was least in the stall with …
Differential Stress Responses In Fish From Areas Of High- And Low-Predation Pressure, Culum Brown, Carolyn Gardner, Victoria Braithwaite
Differential Stress Responses In Fish From Areas Of High- And Low-Predation Pressure, Culum Brown, Carolyn Gardner, Victoria Braithwaite
Aquaculture Collection
We subjected fish from regions of high and low levels of predation pressure in four independent streams to a mild stressor and recorded their opercular beat rates. Fish from low-predation areas showed higher maximum, minimum and mean opercular beat frequencies than fish from high-predation regions. The change in opercular beat frequency (scope) was also significantly greater in fish from low- than in fish from high-predation regions. Under normal activity levels, however, low predation fish showed a reduced opercular beat frequency, which may be indicative of reduced activity levels or metabolic rate. Opercular beat frequency was negatively correlated with standard length …
Number Comprehension By A Grey Parrot (Psittacus Erithacus), Including A Zero-Like Concept, Irene M. Pepperberg, Jesse D. Gordon
Number Comprehension By A Grey Parrot (Psittacus Erithacus), Including A Zero-Like Concept, Irene M. Pepperberg, Jesse D. Gordon
Sentience Collection
A Grey parrot (Psittacus erithacus) that was able to quantify 6 item sets (including subsets of heterogeneous groups, e.g., blue blocks within groupings of blue and green blocks and balls) using English labels (I. M. Pepperberg, 1994a) was tested on comprehension of these labels, which is crucial for numerical competence (K. C. Fuson, 1988). He was, without training, asked “What color/object [number]?” for collections of various simultaneously presented quantities (e.g., subsets of 4, 5, and 6 blocks of 3 different colors; subsets of 2, 4, and 6 keys, corks, and sticks). Accuracy was greater than 80% and was unaffected by …
Big Brains Do Matter In New Environments, Lori Marino
Big Brains Do Matter In New Environments, Lori Marino
Evolutionary Biology Collection
No abstract provided.
Effects Of Predation Pressure On The Cognitive Ability Of The Poeciliid Brachyraphis Episcopi, Culum Brown, Victoria A. Braithwaite
Effects Of Predation Pressure On The Cognitive Ability Of The Poeciliid Brachyraphis Episcopi, Culum Brown, Victoria A. Braithwaite
Sentience Collection
Variable levels of predation pressure are known to have significant impacts on the evolutionary ecology of different populations and can affect life-history traits, behavior, and morphology. To date, no studies have directly investigated the impact of predation pressure on cognitive ability. Here we use a system of replicate rivers, each with sites of high- and low-predation pressure, to investigate how this ecological variable affects learning ability in a tropical poeciliid, Brachyraphis episcopi. We used a spatial task to assess the cognitive ability of eight populations from four independent streams (four high- and four low- predation populations). The fish were required …
The State Of The Animals Iii: 2005, Deborah J. Salem, Andrew N. Rowan
The State Of The Animals Iii: 2005, Deborah J. Salem, Andrew N. Rowan
In this third, all new, volume in the State of the Animals series, scholars and experts in animal protection examine the challenges facing companion animals, marine mammals, and nonhuman primates and review legal protection for animals here and abroad.
Origin And Evolution Of Large Brains In Toothed Whales, Lori Marino, Daniel W. Mcshea, Mark D. Uhen
Origin And Evolution Of Large Brains In Toothed Whales, Lori Marino, Daniel W. Mcshea, Mark D. Uhen
Veterinary Science and Medicine Collection
Toothed whales (order Cetacea: suborder Odontoceti) are highly encephalized, possessing brains that are significantly larger than expected for their body sizes. In particular, the odontocete superfamily Delphinoidea (dolphins, porpoises, belugas, and narwhals) comprises numerous species with encephalization levels second only to modern humans and greater than all other mammals. Odontocetes have also demonstrated behavioral faculties previously only ascribed to humans and, to some extent, other great apes. How did the large brains of odontocetes evolve? To begin to investigate this question, we quantified and averaged estimates of brain and body size for 36 fossil cetacean species using computed tomography and …
Size Matters: A Test Of Boldness In Eight Populations Of The Poeciliid Brachyraphis Episcopi, Culum Brown, Victoria Braithwaite
Size Matters: A Test Of Boldness In Eight Populations Of The Poeciliid Brachyraphis Episcopi, Culum Brown, Victoria Braithwaite
Sentience Collection
Individual variation in behaviour within populations may be explained in part by demographics and long-term, stable individual psychological differences. We examined the relation between boldness (taken as the time to emerge from a shelter and explore a novel environment) and body size in eight populations of the poeciliid Brachyraphis episcopi originating from sites upstream and downstream of waterfalls in four rivers that run into the Panama Canal. The relation between body size and time to emerge from a shelter was positive, with larger fish taking longer to emerge. This relation differed between downstream and upstream sites, being significant in the …
Evolution Of Nociception In Vertebrates: Comparative Analysis Of Lower Vertebrates, Lynne U. Sneddon
Evolution Of Nociception In Vertebrates: Comparative Analysis Of Lower Vertebrates, Lynne U. Sneddon
Veterinary Science and Medicine Collection
Nociception is an important sensory system of major fundamental and clinical relevance. The nociceptive system of higher vertebrates is well studied with a wealth of information about nociceptor properties, involvement of the central nervous system and the in vivo responses to a noxious experience are already characterised. However, relatively little is known about nociception in lower vertebrates and this review brings together a variety of studies to understand how this information can inform the evolution of nociception in vertebrates. It has been demonstrated that teleost fish possess nociceptors innervated by the trigeminal nerve and that these are physiologically similar to …
Free-Stall Dimensions: Effects On Preference And Stall Usage, Cassandra B. Tucker, Daniel M. Weary, David Fraser
Free-Stall Dimensions: Effects On Preference And Stall Usage, Cassandra B. Tucker, Daniel M. Weary, David Fraser
Housing and Confinement of Farm Animals Collection
In 2 experiments, free-stall dimensions were examined to determine how they affected stall preference, usage, cleanliness, and milk production in Holstein dairy cattle. In experiment 1, stall width (112 or 132 cm) and stall length (229 and 274 cm from curb to wall) were compared in a 2 × 2 factorial arrangement of stall treatments using 15 individually housed, non-lactating animals. Cows showed no clear preference for stall size as measured by lying time. When animals had no choice between stalls, average lying time was higher in the wide stalls than in the narrow stalls (10.8 vs. 9.6 ± 0.3 …
Reflections On Animal Selves, Marc Bekoff, Paul W. Sherman
Reflections On Animal Selves, Marc Bekoff, Paul W. Sherman
Sentience Collection
Is self-cognizance a uniquely human attribute, or do other animals also have a sense of self? Although there is considerable interest in this question, answers remain elusive. Progress has been stymied by misunderstandings in terminology, a focus on a narrow range of species, and controversies over key concepts, experimental paradigms and interpretations of data. Here, we propose a new conceptual and terminological framework, emphasizing that degrees of self-cognizance differ among animals because of the cognitive demands that their species-specific social structures and life-history characteristics have placed upon them over evolutionary time. We suggest that the self-cognizance of an organism falls …
Differences In Response To Hypoxia In The Three-Spined Stickleback From Lotic And Lentic Localities: Dominance And An Anaerobic Metabolite, L. U. Sneddon, J. Yerbury
Differences In Response To Hypoxia In The Three-Spined Stickleback From Lotic And Lentic Localities: Dominance And An Anaerobic Metabolite, L. U. Sneddon, J. Yerbury
Aquaculture Collection
Dominance hierarchies of the three-spined stickleback Gasterosteus aculeatus from river and pond populations were subjected to hypoxia (20%, range±1%). Under hypoxia, the hierarchies were less stable in terms of rank position and tissue L-lactate was higher in river fish than pond fish under normoxia and hypoxia. Dominant fish gained mass under normoxia but lost mass under hypoxic conditions possibly due to them maintaining high levels of aggression.
Assessing Animal Welfare At The Farm And Group Level: The Interplay Of Science And Values, D. Fraser
Assessing Animal Welfare At The Farm And Group Level: The Interplay Of Science And Values, D. Fraser
Assessment of Animal Welfare Collection
In the social debate about animal welfare we can identify three different views about how animals should be raised and how their welfare should be judged: (1) the view that animals should be raised under conditions that promote good biological functioning in the sense of health, growth and reproduction, (2) the view that animals should be raised in ways that minimise suffering and promote contentment, and (3) the view that animals should be allowed to lead relatively natural lives. When attempting to assess animal welfare, different scientists select different criteria, reflecting one or more of these value-dependent views. Even when …
Novel Object Test: Examining Nociception And Fear In The Rainbow Trout, Lynne U. Sneddon, Victoria A. Braithwaite, Michael J. Gentle
Novel Object Test: Examining Nociception And Fear In The Rainbow Trout, Lynne U. Sneddon, Victoria A. Braithwaite, Michael J. Gentle
Veterinary Science and Medicine Collection
This study aimed to assess fear responses to a novel object while experiencing a noxious event to determine whether nociception or fear will dominate attention in a fish in novel object testing paradigm. This experimentally tractable animal model was used to investigate (1) the degree of neophobia to a novel object while experiencing noxious stimulation, (2) the response of the fish after removing the fear-causing event by using a familiar object, and (3) the effects of removing the nociceptive response by morphine administration and examining the response to a novel object. Control animals displayed a classic fear response to the …
The Evidence For Pain In Fish: The Use Of Morphine As An Analgesic, Lynne U. Sneddon
The Evidence For Pain In Fish: The Use Of Morphine As An Analgesic, Lynne U. Sneddon
Veterinary Science and Medicine Collection
This paper discusses the evidence for pain perception in fish and presents new data on morphine analgesia in fish. Recent anatomical and electrophysiological studies have demonstrated that fish are capable of nociception, the simple detection of a noxious, potentially painful stimulus and the reflex response to this. To prove pain perception, it must be demonstrated that an animal’s behaviour is adversely affected by a potentially painful event and this must not be a reflex response. The present study examined the acute effects of administering a noxious chemical to the lips of rainbow trout (Oncorhynchus mykiss) to assess what changes occurred …
Social Learning Of Prey Location In Hatchery-Reared Atlantic Salmon, C. Brown, A. Markula, K. Laland
Social Learning Of Prey Location In Hatchery-Reared Atlantic Salmon, C. Brown, A. Markula, K. Laland
Aquaculture Collection
Naïve, hatchery-reared Atlantic salmon Salmo salar parr were paired with demonstrators that had been pre-trained to accept live prey from the surface or from the benthos. After 6 days of observing demonstrators through a clear perspex partition the naïve fish’s benthic foraging skills were tested. The results revealed that hatchery-reared Atlantic salmon can be taught to target benthic prey items by observation alone and social learning protocols can be utilized to dramatically increase benthic foraging success. The results are discussed with reference to refining hatchery-rearing practices with a view to improving the post-release survival of hatchery fishes. The role of …
Do Fishes Have Nociceptors? Evidence For The Evolution Of A Vertebrate Sensory System, Lynne U. Sneddon, Victoria A. Braithwaite, Michael J. Gentle
Do Fishes Have Nociceptors? Evidence For The Evolution Of A Vertebrate Sensory System, Lynne U. Sneddon, Victoria A. Braithwaite, Michael J. Gentle
Veterinary Science and Medicine Collection
Nociception is the detection of a noxious tissue-damaging stimulus and is sometimes accompanied by a reflex response such as withdrawal. Pain perception, as distinct from nociception, has been demonstrated in birds and mammals but has not been systematically studied in lower vertebrates. We assessed whether a fish possessed cutaneous nociceptors capable of detecting noxious stimuli and whether its behavior was sufficiently adversely affected by the administration of a noxious stimulus. Electrophysiological recordings from trigeminal nerves identified polymodal nociceptors on the head of the trout with physiological properties similar to those described in higher vertebrates. These receptors responded to mechanical pressure, …
Considering Animals—Not “Higher” Primates, Marc Bekoff
Considering Animals—Not “Higher” Primates, Marc Bekoff
Sentience Collection
In this essay I argue that many nonhuman animal beings are conscious and have some sense of self. Rather than ask whether they are conscious, I adopt an evolutionary perspective and ask why consciousness and a sense of self evolved—what are they good for? Comparative studies of animal cognition, ethological investigations that explore what it is like to be a certain animal, are useful for answering this question. Charles Darwin argued that the differences in cognitive abilities and emotions among animals are differences in degree rather than differences in kind, and his view cautions against the unyielding claim that humans, …
Trigeminal Somatosensory Innervation Of The Head Of A Teleost Fish With Particular Reference To Nociception, Lynne U. Sneddon
Trigeminal Somatosensory Innervation Of The Head Of A Teleost Fish With Particular Reference To Nociception, Lynne U. Sneddon
Veterinary Science and Medicine Collection
Trigeminal somatosensory receptors have not been characterised in teleost fish and studies in elasmobranchs have failed to identify nociceptors. The present study examined the trigeminal nerve of a teleost fish, the rainbow trout (Oncorhynchus mykiss) to determine what types of somatosensory receptors were present on the head of the trout specifically searching for nociceptors. Single unit recordings were made from receptive fields on the head of the fish innervated by the trigeminal nerve. Each receptive field was tested for sensitivity to mechanical, thermal and chemical stimulation. Five different receptor types were found: fast adapting receptors responding to mechanical stimulation; slowly …
Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich
Reconstructing Cetacean Brain Evolution Using Computed Tomography, Lori Marino, Mark D. Uhen, Nicholas D. Pyenson, Bruno Frohlich
Veterinary Science and Medicine Collection
Until recently, there have been relatively few studies of brain mass and morphology in fossil cetaceans (dolphins, whales, and porpoises) because of difficulty accessing the matrix that fills the endocranial cavity of fossil cetacean skulls. As a result, our knowledge about cetacean brain evolution has been quite limited. By applying the noninvasive technique of computed tomography (CT) to visualize, measure, and reconstruct the endocranial morphology of fossil cetacean skulls, we can gain vastly more information at an unprecedented rate about cetacean brain evolution. Here, we discuss our method and demonstrate it with several examples from our fossil cetacean database. This …