Veterinary Anatomy Commons^™

The Evolutionary History Of Cetacean Brain And Body Size, Stephen H. Montgomery, Jonathan H. Geisler, Michael R. Mcgowen, Charlotte Fox, Lori Marino, John Gatesy

Veterinary Science and Medicine Collection

Cetaceans rival primates in brain size relative to body size and include species with the largest brains and biggest bodies to have ever evolved. Cetaceans are remarkably diverse, varying in both phenotypes by several orders of magnitude, with notable differences between the two extant suborders, Mysticeti and Odontoceti.We analyzed the evolutionary history of brain and body mass, and relative brain size measured by the encephalization quotient (EQ), using a data set of extinct and extant taxa to capture temporal variation in the mode and direction of evolution. Our results suggest that cetacean brain and body mass evolved under strong directional …

Chondrodysplasia-Like Dwarfism In The Miniature Horse, John E. Eberth

Theses and Dissertations--Veterinary Science

Dwarfism is considered one of the most recognized congenital defects of animals and humans and can be hereditary or sporadic in cause and expression. There are two general morphologic categories within this vastly diverse disease. These categories are disproportionate and proportionate dwarfism and within each of these there are numerous phenotypes which have been extensively described in humans, and to a lesser extent in dogs, cattle, mice, chickens, and other domestic species. Ponies and Miniature horses largely differ from full size horses only by their stature. Ponies are often defined as those whose height is not greater than 14.2 hands; …

Mutations In Dmrt3 Affect Locomotion In Horses And Spinal Circuit Function In Mice, Lisa S. Andersson, Martin Larhammar, Fatima Memic, Hanna Wootz, Doreen Schwochow, Carl-Johan Rubin, Kalicharan Patra, Thorvaldur Arnason, Lisbeth Wellbring, Göran Hjälm, Freyja Imsland, Jessica Lynn Petersen, Molly E. Mccue, James R. Mickelson, Gus Cothran, Nadav Ahituv, Lars Roepstorff, Sofia Mikko, Anna Vallstedt, Gabriella Lindgren, Leif Andersson, Klas Kullander

Department of Animal Science: Faculty Publications

Locomotion in mammals relies on a central pattern-generating circuitry of spinal interneurons established during development that coordinates limb movement. These networks produce left–right alternation of limbs as well as coordinated activation of flexor and extensor muscles. Here we show that a premature stop codon in the DMRT3 gene has a major effect on the pattern of locomotion in horses. The mutation is permissive for the ability to perform alternate gaits and has a favorable effect on harness racing performance. Examination of wild-type and Dmrt3-null mice demonstrates that Dmrt3 is expressed in the dI6 subdivision of spinal cord neurons, takes …

Human Induced Rotation And Reorganization Of The Brain Of Domestic Dogs, Taryn Roberts, Paul Mcgreevy, Michael Valenzuela

Anatomy Collection

Domestic dogs exhibit an extraordinary degree of morphological diversity. Such breed-to-breed variability applies equally to the canine skull, however little is known about whether this translates to systematic differences in cerebral organization. By looking at the paramedian sagittal magnetic resonance image slice of canine brains across a range of animals with different skull shapes (N = 13), we found that the relative reduction in skull length compared to width (measured by Cephalic Index) was significantly correlated to a progressive ventral pitching of the primary longitudinal brain axis (r = 0.83), as well as with a ventral shift in the position …

Hair Whorls In The Dog (Canis Familiaris), Part Ii: Asymmetries, Lisa M. Tomkins, Paul Mcgreevy

Anatomy Collection

In horses and cattle, hair whorls have been shown to act as a structural marker of reactivity and behavioral lateralization. Few studies on canine whorls have been reported and none have assessed whorl position or direction of flow. This study describes the distribution and characteristics of whorl in each of 10 regions in which whorls are typically located in dogs. Hair whorls were assessed in dogs (n = 120) and were recorded as clockwise or counterclockwise in the cephalic, cervical (dorsal, lateral, ventral), thoracic and brachial axillary, chest, shoulders, elbows, abdominal, and ischiatic regions. Bilateral whorls, including brachial axillary, elbow, …

Hair Whorls In The Dog (Canisfamiliaris). I. Distribution, Lisa M. Tomkins, Paul Mcgreevy

Anatomy Collection

Hair whorl characteristics were assessed in the domestic dog (Canis familiaris) in the regions of cephalic, cervical (dorsal, ventral, and lateral), thoracic and brachial axillary regions, the chest, shoulders, elbows, ventral abdominal region, and on the caudal thighs (ischiatic). They were classified as simple or tufted, and their position was recorded as the distance between their centers and bony landmarks within each region. The distribution of whorls was explored in a cohort of domestic dogs (N = 120) comprising a variety of breeds and cross‐breeds, sourced from shelters (N = 60) and the general public (N = 60). …

Neuroanatomy Of The Subadult And Fetal Brain Of The Atlantic White-Sided Dolphin (Lagenorhynchus Acutus) From In Situ Magnetic Resonance Images, Eric W. Montie, Gerald E. Schneider, Darlene R. Ketten, Lori Marino, Katie E. Touhey, Mark E. Hahn

Veterinary Science and Medicine Collection

This article provides the first anatomically labeled, magnetic resonance imaging (MRI) -based atlas of the subadult and fetal Atlantic white-sided dolphin (Lagenorhynchus acutus) brain. It differs from previous MRI-based atlases of cetaceans in that it was created from images of fresh, postmortem brains in situ rather than extracted, formalin-fixed brains. The in situ images displayed the classic hallmarks of odontocete brains: fore-shortened orbital lobes and pronounced temporal width. Olfactory structures were absent and auditory regions (e.g., temporal lobes and inferior colliculi) were enlarged. In the subadult and fetal postmortem MRI scans, the hippocampus was identifiable, despite the relatively small size …

Cetacean Brains: How Aquatic Are They?, Lori Marino

Anatomy Collection

The adaptation of cetaceans to a fully aquatic lifestyle represents one of the most dramatic transformations in mammalian evolutionary history. Two of the most salient features of modern cetaceans are their fully aquatic lifestyle and their large brains. This review article will offer an overview of comparative neuroanatomical research on aquatic mammals, including analyses of odontocete cetacean, sirenian, pinniped, and fossil archaeocete brains. In particular, the question of whether a relationship exists between being fully aquatic and having a large brain is addressed. It has been hypothesized that the large, well‐developed cetacean brain is a direct product of adaptation to …

Cetaceans Have Complex Brains For Complex Cognition, Lori Marino, Richard C. Connor, R. Ewan Fordyce, Louis M. Herman, Patrick R. Hof, Louis Lefebvre, David Lusseau, Brenda Mccowan, Esther A. Nimchinsky, Adam A. Pack, Luke Rendell, Joy S. Reidenberg, Diana Reiss, Mark D. Uhen, Estel Van Der Gucht, Hal Whitehead

Anatomy Collection

We believe that the time is ripe to present an integrated view of cetacean brains, behavior, and evolution based on the wealth of accumulated and recent data on these topics. Our conclusions support the more generally accepted view that the large brain of cetaceans evolved to support complex cognitive abilities.

Preventing Back Pain In Horses, Jenifer Nadeau

Extension Articles

Back pain is a source of poor performance and many different types of horses suffer from back problems. Early recognition of back pain is important, since damage may be cumulative. This information is provided to help horse owners and riders prevent, recognize, and pursue treatment for back pain in their horses.

Does Diving Limit Brain Size In Cetaceans?, Lori Marino, Daniel Sol, Kristen Toren, Louis Lefebvre

Veterinary Science and Medicine Collection

We test the longstanding hypothesis, known as the dive constraint hypothesis, that the oxygenation demands of diving pose a constraint on aquatic mammal brain size.Using a sample of 23 cetacean species we examine the relationship among six different measures of relative brain size, body size, and maximum diving duration. Unlike previous tests we include body size as a covariate and perform independent contrast analyses to control for phylogeny. We show that diving does not limit brain size in cetaceans and therefore provide no support for the dive constraint hypothesis. Instead, body size is the main predictor of maximum diving duration …

Cetacean Brain Evolution: Multiplication Generates Complexity, Lori Marino

Anatomy Collection

Over the past 55-60 million years cetacean (dolphin, whale, and porpoise) brains have become hyperexpanded so that modern cetacean encephalization levels are second only to modern humans. At the same time, brain expansion proceeded along very different lines than in other large-brained mammals so that substantial differences between modern cetacean brains and other mammalian brains exist at every level of brain organization. Perhaps the most profound difference between cetacean and other mammalian brains is in the architecture of the neocortex. Cetaceans possess a unique underlying neocortical organizational scheme that is particularly intriguing in light of the fact that cetaceans exhibit …

Neuroanatomy Of The Killer Whale (Orcinus Orca) From Magnetic Resonance Images, Lori Marino, Chet C. Sherwood, Bradley N. Delman, Cheuk Y. Tang, Thomas P. Naidisch, Patrick R. Hof

Veterinary Science and Medicine Collection

This article presents the first series of MRI-based anatomically labeled sectioned images of the brain of the killer whale (Orcinus orca). Magnetic resonance images of the brain of an adult killer whale were acquired in the coronal and axial planes. The gross morphology of the killer whale brain is comparable in some respects to that of other odontocete brains, including the unusual spatial arrangement of midbrain structures. There are also intriguing differences. Cerebral hemispheres appear extremely convoluted and, in contrast to smaller cetacean species, the killer whale brain possesses an exceptional degree of cortical elaboration in the insular cortex, temporal …

Neuroanatomical Structure Of The Spinner Dolphin (Stenella Longirostris Orientalis) Brain From Magnetic Resonance Images, Lori Marino, Keith Sudheimer, William A. Mclellan, John I. Johnson

Veterinary Science and Medicine Collection

High-resolution magnetic resonance (MR) images of the brain of an adult spinner dolphin (Stenella longirostris orientalis) were acquired in the coronal plane at 55 antero-posterior levels. From these scans a computergenerated set of resectioned virtual images in the two remaining orthogonal planes was constructed with the use of the VoxelView and VoxelMath (Vital Images, Inc.) programs. Neuroanatomical structures were labeled in all three planes, providing the first labeled anatomical description of the spinner dolphin brain.

Magnetic Resonance Images Of The Brain Of A Dwarf Sperm Whale (Kogia Simus), L. Marino, K. Sudheimer, D. A. Pabst, J. I. Johnson

Veterinary Science and Medicine Collection

Cetacean (dolphin, whale and porpoise) brains are among the least studied mammalian brains because of the difficulty of collecting and histologically preparing such relatively rare and large specimens. Among cetaceans, there exist relatively few studies of the brain of the dwarf sperm whale (Kogia simus). Magnetic resonance imaging (MRI) offers a means of observing the internal structure of the brain when traditional histological procedures are not practical. Therefore, MRI has become a critical tool in the study of the brain of cetaceans and other large species. This paper represents the first MRI-based anatomically labelled three-dimensional description of the dwarf sperm …

Neuroanatomy Of The Common Dolphin (Delphinus Delphis) As Revealed By Magnetic Resonance Imaging (Mri), L. Marino, Keith Sudheimer, D. Ann Pabst, William A. Mclellan, David Filsoof, John I. Johnson

Veterinary Science and Medicine Collection

In this study, magnetic resonance (MR) images of the brain of an adult common dolphin (Delphinus delphis) were acquired in the coronal plane at 66 antero-posterior levels. From these scans a computer-generated set of resectioned virtual images in orthogonal planes was constructed using the programs VoxelView and VoxelMath (Vital Images, Inc., Michigan State Univ.). Sections in all three planes reveal major neuroanatomical structures. These structures in the adult common dolphin brain are compared with those from a fetal common dolphin brain from a previously published study as well as with MR images of adult brains of other odontocetes. …

Anatomical And Electrophysiological Analysis Of The Trigeminal Nerve In A Teleost Fish, Oncorhynchus Mykiss, Lynne U. Sneddon

Veterinary Science and Medicine Collection

The trigeminal nerve in the rainbow trout, Oncorhynchus mykiss, was examined for the presence of A-delta and C fibres. Sections of the three branches of the trigeminal nerve were found to comprise a range of fibre types including Adelta and C fibres. The size range of the cell bodies of the trigeminal ganglion reflected the fibre range since they correlated with the size range of axons in the nerve branches. Electrophysiological recordings of evoked activity from the ganglion confirmed the presence of these fibre types and the proportion of these mirrored the proportion of fibre types in the anatomical analyses. …

Anatomy And Three-Dimensional Reconstructions Of The Brain Of The White Whale (Delphinapterus Leucas) From Magnetic Resonance Images, Lori Marino, Timothy L. Murphy, Amy L. Deweerd, John A. Morris, Archibald J. Fobbs, Nathalie Humbolt, Sam H. Ridgway, John I. Johnson

Veterinary Science and Medicine Collection

Magnetic resonance imaging offers a means of observing the internal structure of the brain where traditional procedures of embedding, sectioning, staining, mounting, and microscopic examination of thousands of sections are not practical. Furthermore, internal structures can be analyzed in their precise quantitative spatial interrelationships, which is difficult to accomplish after the spatial distortions often accompanying histological processing. For these reasons, magnetic resonance imaging makes specimens that were traditionally difficult to analyze, more accessible. In the present study, images of the brain of a white whale (Beluga) Delphinapterus leucas were scanned in the coronal plane at 119 antero-posterior levels. Fromthese scans, …

Relative Volume Of The Cerebellum In Dolphins And Comparison With Anthropoid Primates, L. Marino, James K. Rilling, Shinko K. Lin, Sam H. Ridgway

Veterinary Science and Medicine Collection

According to the ‘developmental constraint hypothesis’ of comparative mammalian neuroanatomy, brain growth follows predictable allometric trends. Therefore, brain structures should scale to the entire brain in the same way across mammals. Evidence for a departure from this pattern for cerebellum volume has recently been reported among the anthropoid primates. One of the mammalian groups that has been neglected in tests of the ‘developmental constraint hypothesis’ is the cetaceans (dolphins, whales, and porpoises). Because many cetaceans possess relative brain sizes in the range of primates comparative tests of the ‘developmental constraint hypothesis’ across these two groups could help to delineate the …

Social Deprivation Of Infant Rhesus Monkeys Alters The Chemoarchitecture Of The Brain: I. Subcortical Regions, Lee J. Martin, Dawn M. Spicer, Mark H. Lewis, John P. Gluck, Linda C. Cork

Veterinary Science and Medicine Collection

Rhesus monkeys (Macaca mulatta) reared during the first year of life without social contact develop persistent stereotyped movements, self-directed behaviors, and psychosocial abnormalities, but neurobiological mechanisms underlying the behaviors of socially deprived (SD) monkeys are unknown. Monkeys were reared in total social deprivation for the first 9 months of life; control monkeys were reared socially (SR) with mothers and peers. Subjects were killed at 19-24 yr of age. Because the behaviors of SD monkeys are reminiscent of changes in striatal or amygdalar function, we used immunocytochemistry for substance P (SP), leutine-enkephalin (LENK), somatostatin, calbindin, and tyrosine hydroxylase (TH) to evaluate …

An Attempt To Estimate Teat Quality Of Sows By Hand Milking During Farrowing, D. Fraser, C. S. Lin

Anatomy Collection

For 21 sows, teats were hand milked individually in a standard way during farrowing in an attempt to produce an index of teat quality. The piglets' teat selection and 14-day weights were then compared with the hand milking results. Of within-litter variation in 14-day weight, 38.67% was explained by 1-day weight, and only 4.6% extra variation by the index derived from hand milking. Use of the index gave no improvement over previous models involving 1-day weight and teat number (anterior to posterior). Hand milking showed a pronounced decline in colostrum yield from the most anterior teat pair (46.8 g) to …

Observations On Relationships Between Limb Measurements And Mode Of Locomotion In Malaysian Turtles, Duayne Nyckel

Masters Theses

Twelve Genera (spanning three Families) of Malaysian Turtles were studied to determine whether bone lengths could be correlated to mode of locomotion. Ulna, humerus, tibia, femur, coracoid (among others) were measured and results were presented graphically. Five of the genera were observed singly in a large aquarium. Data were recorded on the amount of time each spent in different locomotor modes. Both limb length data and aquarium observations suggest that turtles can be grouped into three main locomotor habits (i.e. terrestrial walking, bottomwalking, and swimming). The terrestrial group includes the genera, Geochelone, Kinixys, and Gopherus. Bottomwalkers include …

The Effects Of Insulin On Hepatic Glucocorticoid Receptor Content In The Diabetic Rat, Jeffrey John Yourick

Masters Theses

The streptozotocin-induced diabetic rat liver was analyzed for glucocorticoid receptor (GCR) content by a saturation and Scatchard analysis. A preliminary study was performed on the stabilization of the cytoplasmic GCR in a frozen cytosol preparation. The addition of 10% glycerol (V/V), 10 mM sodium molybdate, and 0.2 mg/ml trypsin inhibitor resulted in an approximate 20% sparing of GCR content upon freezing.

The hepatic GCR content of diabetic rats was significantly decreased from a control level of 0.1667 ± 0.0142 pmol/mg protein to 0.1094 ± 0.007 pmol/mg protein. Insulin replacement therapy to the diabetic rat dramatically increased the hepatic GCR content. …

The Effects Of Prostaglandin E2 On The Healing Processes Of Rat Perforated Tympanic Membranes, Diane Sue Saylor

Masters Theses

Prostaglandin E₂ (PGE₂) was topically administered to perforated rat tympanic membranes in an attempt to facilitate regrowth of the membranes. Every 24 hours for the first four postperforation days, two groups of tympanic membranes were processed and examined histologically for differences between PGE₂ treated and control animals.

At 24 hours postperforation granulocyte infiltration at the perforation site was greater in the test animals. By 48 hours blood clots were larger in PGE₂ treated animals. Finally, the epithelium was thinner in test animals than in control animals at 96 hours.

Slight tendencies for the test animals …

Amputation Of Vibrissae In Show Dogs, Thomas E. Mcgill

International Journal for the Study of Animal Problems

No abstract provided.

Time-Related Changes In Rat Androgen Binding Protein Following A Sterilizing Dose Of 3-Chloro-1, 2-Propanediol, Shirley J. Stein

Masters Theses

Androgen binding protein (ABP) is produced by the Sertoli cell, regulated by FSH and androgens, secreted into the testicular fluid, and transported into the caput epididymis where it is thought to play a role in sperm maturation. In this study, the response of ABP to a lesion created chemically by administration of a single, oral 60 mg/kg dose of alpha-chlorohydrin was examined in ninety day old male rats. Total testicular ABP content increased progressively for four days after treatment and there after declined whereas, epididymal ABP concentration decreased immediately. Serum testosterone showed no significant variation from controls, however, serum FSH …

A Survey Of Shearing Times, B R. Beetson

Journal of the Department of Agriculture, Western Australia, Series 4

When do farmers in W.A. shear their sheep, and why do they selest the times they do?

A Department of Agriculture survey attempted to answer these questions, which have important implications for the wool industry.

A Study Of Regulation Of Oxidative Metabolism By Substances Present In The Suprapharyngeal Ganglia And Ventral Nerve Cord In Lumbricus Terrestris, Mary Peremuh

Masters Theses

No abstract provided.

The Influence Of Nicotine On The Effect Of Secretin On Gastric Secretion In The Rat And Dog, Donald H. Currie

Masters Theses

No abstract provided.

Seasonal Variation In The Tubular And Interstitial Areas Of The Testes In Sternotherus Odoratus L., Robert Hans Spaet

Masters Theses

Seasonal changes within the tubular and interstitial areas of the testes in Sternotherus odoratus are investigated, histologically and histochemically. Forty specimens were collected in Illinois, Tennessee and Louisiana between May, 1969 and August, 1972.

Many of the histological and macroscopic observations made by Risley (1938) on the spermatogenic cycle of S. odoratus in Michigan are confirmed. Contrary to his findings, fluctuations in interstitial cell nuclear diameters are observed during spermatogenesis. Greatest diameters coincide with what Risley has considered " . . . period of most active breeding." Sertoli cell nuclear diameters undergo similar fluctuations being greatest during spring breeding and …