Caudal Colliculus Research Articles

The macromorphological structure of the rhomboid brain of the whitebellied hedgehog

The nervous system is one of the leading integrating systems of the body. In combination with the cardiovascular and endocrine systems, it unites the body into a single whole. The nervous system controls the level of adaptive reactions of a living organism to changing environmental conditions. The white-bellied hedgehog (Atelerix albiventris) is a representative of the order of insectivorous animals. The purpose of our study is to study the macromorphology of individual anatomical structures of the brain of the white-bellied hedgehog (Atelerix albiventris). The material for the study was three heterosexual animals of the white-bellied hedgehog species (Atelerix albiventris) aged 1-4 years, obtained from private veterinary clinics. The methods used to study the brain of the white-bellied hedgehog included: fine anatomical dissection, morphometry, photography, and weighing. The work was carried out at the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. The brain of the whitebellied hedgehog (Atelerix albiventris) (Figure 1, 2.) is arranged in accordance with the general plan of the structure of the mammalian brain, however, it is distinguished by the primitiveness of its development and is classified as lissencephalic in appearance. The average weight of cadaver material from females and males was 200.00±16.09 grams. There was no statistically significant difference between the body weight of females and males. It was also found that the caudal colliculi of the quadrigeminal are comparatively smaller than the cranial colliculi in both sexes, which allows us to conclude that the visual analyzer is relatively better developed in this species than the auditory one. The obtained materials can be used as reference material for continuing research on the brain of the white-bellied hedgehog (Atelerix albiventris), as well as in comparative morphology and physiology of humans and animals.

Meningoencephalomyelitis associated with foreign plant material in a dog: case report and brief literature review.

Neurologic disease associated with migration of plant material is reported infrequently in dogs. Here we describe meningoencephalomyelitis associated with foreign plant material in a 2-y-old castrated male West Highland White Terrier dog with acute neck pain. Magnetic resonance imaging revealed spinal meningeal contrast enhancement. Although clinical signs improved after treatment with steroids, the dog was readmitted for further evaluation 3-mo later and was euthanized after generalized epileptic seizures. Autopsy findings consisted of coalescing, pus-filled, neuroparenchymal cavitations surrounded by hemorrhage in the left caudal colliculus and rostral left cerebellar hemisphere. Histologically, lesions consisted of necrosis and suppuration, which surrounded a 1 × 2-mm foreign body morphologically consistent with plant material and clusters of gram-positive bacterial cocci. Affected areas were surrounded by reactive astrocytes, fibrous connective tissue, and mixed inflammatory infiltrates. Areas of hemorrhage and infiltration by neutrophils and foamy macrophages with fibrinoid change of small capillaries were observed in the adjacent neuroparenchyma. The inflammation extended to the perivascular spaces in the leptomeninges (mesencephalon, cerebellum, and brainstem, and spinal cord) and spinal central canal. Anaerobic bacterial culture of frozen samples of cerebellum yielded heavy growth of Bacteroides pyogenes.

Virtual endocast of late Paleocene Niptomomys (Microsyopidae, Euarchonta) and early primate brain evolution

Paleogene microsyopid plesiadapiforms are among the oldest euarchontans known from relatively complete crania. While cranial endocasts are known for larger-bodied Eocene microsyopine microsyopids, this study documents the first virtual endocast for the more diminutive uintasoricine microsyopids, derived from a specimen of Niptomomys cf. Niptomomys doreenae (USNM 530198) from the late Paleocene of Wyoming. Size estimates of smaller-bodied uintasoricines are similar to those inferred for the common ancestor of Primates, so the virtual endocast of Niptomomys may provide a useful model to study early primate brain evolution. Due to the broken and telescoped nature of the neurocranium of USNM 530198, a μCT scan of the specimen was used to create a 3D model of multiple bone fragments that were then independently isolated, repositioned, and merged to form a cranial reconstruction from which a virtual endocast was extracted. The virtual endocast of Niptomomys has visible caudal colliculi, suggesting less caudal expansion of the cerebrum compared to that of euprimates, but similar to that of several other plesiadapiforms. The part of the endocast representing the olfactory bulbs is larger relative to overall endocast volume in Niptomomys (8.61%) than that of other known plesiadapiforms (∼5%) or euprimates (<3.5%). The petrosal lobules (associated with visual stabilization) are relatively large for a Paleocene placental mammal (1.66%). The encephalization quotient of Niptomomys is relatively high (range = 0.35–0.85) compared to that of Microsyops (range = 0.32–0.52), with the upper estimates in the range of values calculated for early euprimates. However, this contrast likely relates in part to the small size of the taxon, and is not associated with evidence of neocortical expansion. These findings are consistent with a model of shifting emphasis in primate evolution toward functions of the cerebrum and away from olfaction with the origin of euprimates.

Comparative cytoarchitecture of the midbrain colliculi of defined age groups in the African giant pouched rat (Cricetomys gambianus)

Background: The rostral and caudal colliculi of mammalian midbrain are pivotal to vision and audition, respectively. Cytoarchitecture of these midbrain colliculi in neonate, juvenile and adult African giant pouched rats is dearth.&#x0D; Objective: This study compared the histology of the nuclei, neurons and laminations of the colliculi in these age groups.&#x0D; Methods: Thirty-six captive African giant pouched rats consisting of twelve neonates, juveniles and adults were used. Thickness of the histologic layers of the rostral colliculi and lengths of the central nucleus of the caudal colliculi were compared among the groups.&#x0D; Results: the rostral colliculus composed of an outermost stratum zonale, middle stratum griseum superficiale and innermost stratum griseum profundus; migratory immature neurons of radial glial cells were observed in the stratum zonale of neonates, which disappeared in juveniles and adults; the stratum griseum superficiale of neonates was characterized of already formed neurites, similar to those of the juveniles and adults. However, this layer in adults had more oligodendrocytes than in juveniles. There was significant increase in thickness of the stratum griseum superficiale and stratum griseum profundus, with increasing age (P &lt; 0.05). The caudal colliculus contained a central nucleus, dorsal and lateral cortices, with significant increase in the length of the central nucleus with increasing age (P &lt; 0.05); there was transformation of fibre shaft in the lateral cortex of neonates into a mixture of chain like and marshy matrix in the juveniles which completely disappeared in adults, indicative of mature lateral cortex in the later.&#x0D; Conclusion: The adult African giant pouched rat may have the best auditory and visual senses, followed by juvenile. The neonate has the least acuity of these senses.

Comparative morphology and morphometry of the mesencephalic tectum in the African giant rat (Cricetomys gambianus).

The caudal colliculus serves as an integrative station and switchboard, controlling nucleus of lower auditory pathway and motor-auditory reflex production. The rostral colliculus coordinates reflexive movement of the head, neck, eye and focus the lens for visual tracking of objects. There is no information comparing mesencephalic tectum among neonates, juveniles and adults of African giant rat (AGR). Hence, this study aimed to compare the gross features and morphometric parameters of mesencephalic tectum postnatally in AGR. The following were found and reported: (a) Paired dorsal tips of caudal colliculi were observed through transverse fissure of the intact brain and so, corpora quadrigemina were partly occluded by cerebral cortex in neonates and juveniles. (b) The lateral and medial geniculate bodies were visible, though the lateral was grossly bigger than the medial in adults and juveniles but, only the lateral was distinguishable in neonates. (c) Live body weight, absolute brain weight, caudal colliculus width, nose-rump and tail lengths increased as AGRs developed with age; mean values of rostral colliculus weight, caudal colliculus height and weight of caudal colliculus in neonates and juveniles were statistically same; while midbrain weight and rostral colliculus height tends to decrease as rats aged. (d) The mean weight of caudal colliculi and width of rostral colliculi were not affected by age. (e) Caudal colliculi were grossly wider than rostral in juveniles and adults, but not neonates. Established regression formulae are necessary to avoid future sacrifice of this rodent.

Anatomical Demonstration of the Cognitive Ability of the Juvenile African Giant Pouched Rat (Cricetomys gambianus – Waterhouse, 1840)

Cognitive ability in animals is determined using indices such as Encephalisation Quotient (EQ), relative brain weight, glial quotient and neuronal index. In this study, the cognitive ability of the juvenile African giant pouched rat was determined using the EQ and relative brain weight. Brain samples were routinely extracted from thirty-two juvenile (16 males and 16 females, respectively) rats and fixed in freshly prepared 10% buffered formalin. The nose-rump length, tail length absolute and relative brain weights were determined according to standard technique while the EQ was computed using the Martin’s formula. Structural observations revealed a diamond shaped lissencephalic cerebral cortex with the caudal colliculi exposed from the dorsal transverse fissure of the intact brain. An EQ of 0.75 was deduced for the juvenile African giant pouched rat from the study. Sexual dimorphic analysis revealed mean relative brain weight of 6.64 ± 0.30 and 6.90 ± 0.22 and mean EQ of 0.71 ± 0.06 and 0.78 ± 0.02, for the male and female juveniles respectively. The mean differences between the males and females were not statistically significant (P &gt; 0.05). However, there was a significant negative correlation between nose-rump length and EQ (R2 = 0.66; p &lt; 0.05), nose-rump length and relative brain length (r2 = 0.49; p &lt; 0.05) as well as nose-rump length and relative weight of cerebrum (R2 = 0.61; p &lt; 0.05). The results were compared with that of other age groups of the same rodent and other juvenile rodents. It was concluded that the juvenile African giant pouched rat may be a better choice for memory and cognitive studies than the adult.

Characteristics of Physiological 18F-Fluoro-2-Deoxy-D-Glucose Uptake and Comparison Between Cats and Dogs With Positron Emission Tomography.

This study aimed to identify the physiological 18F-fluoro-2-deoxy-D-glucose (FDG) uptake in cats using positron emission tomography/computed tomography (PET/CT) and determine its characteristics by comparing physiological differences with dogs. Seven healthy cats and six healthy beagle dogs were examined using FDG-PET/CT. Regions of interest (ROIs) were manually drawn over 41 detailed structures of 5 gross structures (brain, head and neck, musculoskeleton, thorax, and abdomen). The mean and maximum standard uptake values (SUVmean and SUVmax) were calculated for each ROI. Physiological variation was classified as having increased radiopharmaceutical activity with no evidence of abnormal clinical or radiological findings. The brain had the highest SUV, which was observed in the cerebellum of both cats (SUVmean: 4.90 ± 1.04, SUVmax: 6.04 ± 1.24) and dogs (SUVmean: 3.15 ± 0.57, SUVmax: 3.90 ± 0.74). Cats had a significantly higher intracranial uptake than dogs did (P < 0.01). In the digestive system, the SUVs of the duodenum and jejunum were significantly higher in dogs than in cats (P < 0.05). FDG uptake of the submandibular tip, tonsils, neck of the gallbladder, and caudal colliculus were physiologically increased in cats. This study demonstrates physiological FDG uptake in normal tissues, and the differences between cats and dogs were interpreted based on species-specificity. This information contributes to improving the accurate diagnosis of cancer in cats and will aid in understanding glucose metabolism in both cats and dogs.

Cenurosis in a Sheep with Neurological Signs - Diagnosis with Computed Tomography

Background: Cenurosis is a parasitic disease caused by Coenurus cerebralis, an intermediate form of Taenia multiceps multiceps, causing a fatal disease in production animals. Its adult form (Taenia) lodges in the small intestine of canids and can infect several intermediate hosts.Sheep are the main species affected by the disease, having nervous symptoms as one of its manifestations.This study aimed to describe the changes observed in computed tomography, as well as the clinical findings of a case of Cenurosis in a sheep on the western border of Rio Grande do Sul.Case: A ram was referred to the Centro Universitário da Região da Campanha (URCAMP) with neurological signs.Clinical, hematological, radiographic, tomographic and necroscopic evaluation of the animal was performed.There were no significant hematological and radiographic changes.During the neurological examination, corneal opacity was found in the right eyeball, associated with a visual deficit in the same eye.Also, when stimulated to move, it was possible to observe ataxia with ambulation to the left side, with right lateral displacement of the head.The tomography showed a hypodense area of approximately 3 cm at the base of the brain, in the region of the thalamus and third ventricle.Macroscopically, a translucent spherical cyst with approximately 4 cm in diameter was observed, containing the protoescolex/scolices of Taenia multiceps in the same region.Discussion: Computed tomography identified the presence of an apparently circular volume of approximately 4 cm in diameter, causing ventricular dilatation.This evidence of ventricular dilation corroborates aspects described in the literature, which found bilateral dilation of the ventricles by compression promoted by a cyst in the 4th ventricle.As the location of the cyst was located at the base of the brain, in the region of the third ventricle, it would be difficult to perform the surgery in the treatment of this case.Signs of ataxia, walking movements, decreased reflexes, nystagmus, unilateral blindness and lateral decubitus are commonly observed.Reports described that the main neurological alterations observed in 20 sheep with cenurosis were postural deficit, locomotion alteration, visual deficit and behavioral alterations, with more than 50% of the animals showing at least one of these signs.The main neurological signs observed in the case described were changes in gait, with walking, blindness, lateral head deviation and ataxia. These signs guide the clinical diagnosis of cenurosis.At necropsy, a spherical translucent cyst with approximately 4 cm in diameter was observed, containing the protoescolex/scolices of Taenia multiceps, which extended dorsally from the third ventricle to the base of the thalamus, laterally displaced to the right side.Rostrocaudal the lesion extended rostrally across the entire length of the thalamus to the beginning of the caudate nucleus and caudally to the base of the caudal colliculus, causing compression of the adjacent parenchyma, enabling the diagnosis of cenurosis.Similar findings are described as Coenurus cerebralis. This lesion pattern macroscopically characterizes the parasite lesions.Thus, it is concluded that the visualization of a hypodense area in CNS regions of sheep with neurological signs allows the diagnosis of cenurosis and precise location of the lesion.The description of this case adds information so that other professionals in the field can be successful in diagnosing the disease.Keywords: parasitologia, Taenia multiceps multiceps, Coenurus cerebralis, ovelhas, torneio verdadeiro.Descritores: parasitology, Taenia multiceps multiceps, Coenurus cerebralis, sheep, true tournament.Título: Cenurose em ovino com sinais neurológicos - diagnóstico com tomografia computadorizada.

Gross Morphology of the Cerebrum and Brainstem of the Adult African Grasscutter (Thryonomys Swinderianus—Temminck, 1827)

Abstract In order to meet the increasing protein and income demand in Africa due to the rapid population growth, wildlife, such as the African grasscutter, is currently bred and domesticated as microlivestock. This study is one of the series on the brain morphology of this very large rodent, aimed at providing information that is lacking in the literature. Here, the gross anatomy of the cerebrum and brainstem in nine adult African grasscutters is described. The cerebral cortex was smooth, devoid of gyri and sulci, thus, placing the rodent in the lissencephalic group of mammals. However, blood vessels on the cortex created arterial and venous impressions. The cortex was asymmetrically-tapered oval in shape. The rostral and caudal colliculi were exposed through the cerebral transverse fissure. The rostro-caudal extent of the corpus callosum was from the mid-point of the frontal and parietal lobes, to a point just rostral to the occipital lobe. The rostral colliculi were grossly smaller than the caudal colliculi. The occulomotor and trochlear nerves emerged from the ventral midbrain, rostral to the pons. The pons was exceptionally large; it was pre-trigeminal. On either side of the ventral median fissure of the medulla oblongata were conspicuous pyramids. The trapezoid bodies were also conspicuous. These, and other findings, will be useful in future phylogenetic comparison of rodent brain morphology.

Histology and Brain Derived Neurotrophic Factor immunoreaction of the neurons in the corpora quadrigemina of the African grasscutter (Thryonomys swinderianus – Temminck, 1827)

Abstract The African grasscutter is the second largest rodent in Africa, thus, a key component of the minilivestock industry. The study described the histological features and probed the distribution of Brain Derived Neurotrophic Factor (BDNF) in the corpora quadrigemina of the African grasscutter at foetal and postnatal developmental periods. Brain samples from foetuses explanted on foetal days 60 (F60) and 90 (F90) and extracted from 3 and 6-days-old pups (P3 and P6, respectively), 72-days-old juveniles (P72) and 450-days-old adults (P450) were used. They were prepared for histology and immunohistochemistry. Three laminae were distinct in the rostral colliculi at the foetal and postnatal periods; an outermost stratum zonale, middle stratum griseum superficiale and an inner stratum griseum profundum. Stratum griseum intermediale and stratum medullarium were not distinct. On F60 and F90, the stratum zonale was made of immature neurons, devoid of neurites; the central nucleus of the caudal colliculus was also made of immature migrating neurons. On P3, the neurons were already mature. The stratum zonale was made of medium-sized neuronal cells and thick processes. The thickness of this layer decreased with age. On P3, the caudal colliculus was made of all the components typical of a developed caudal colliculus. There was no BDNF immunoreactive cell in the stratum zonale at any postnatal period; a moderate BDNF-immunoreactivity in the stratum griseum superficiale on P3, a mild immunoreactivity on P6, none reactivity on P72 and mild on P450. The dorsal and lateral cortices of the caudal colliculus were none reactive to BDNF at any postnatal period. The results suggest a better auditory than visual capacity in the rodent.

Gross Anatomy and Vascularization of the Brain of Pacarana (Dinomys branickii)

Background: The pacarana lives in South America and has herbivorous and nocturnal habits. It is a rare species with scarce data concerning its morphology and adding more data is important in establishing its vulnerability. The aim was to describe its macroscopic brain anatomy, as well as the brain vascularization.Materials, Methods &amp; Results: Two specimens were available for this study, that were donated post-mortem. The animals were injected with latex and fixed with 10% formaldehyde. Upon exposure and removal of the brain its main features were described. The rhinal fissure is single and the lateral sulcus arises from its caudal part. There are two sagittal sulci, an extensive medial sulcus and a short lateral sulcus. The piriform lobe is vermiform and the rostral part is smaller. The caudal colliculus is larger than the rostral colliculus and they are separated by a sulcus. The cerebellum has oval shape and the flocculus lobe is not conspicuous. The cerebral arterial circle was analyzed and described. The brain is supplied by the vertebrobasilar system only. The cerebral arterial circle is formed by the terminal branch of the basilar artery, the caudal communicating artery, the rostral cerebral artery and the rostral communicating artery. The caudal and middle cerebellar arteries are branches of the basilar artery. The terminal branch of the basilar artery originates the rostral cerebellar artery and the caudal cerebral artery. From the end of the caudal communicating artery and the beginning of the rostral cerebral artery arises the middle cerebral artery.Discussion: The cerebral structures related to sensory inputs reflect the species usage of senses, or rather one is intrinsically correlated to the other. The caudal colliculus is larger than the rostral colliculus, as the former is related to hearing and the latter to the vision, this indicates that the visual sense is not so important. Indeed, the animals are nocturnal and have small eyes. The hearing on the other hand is used in social interactions, to indicate combat, threat and defensive situations, for example. The rhinencephalon has the most conspicuous external sensory structures and the animals use olfaction for social behaviors, even producing a gland exudate to mark territory. Most brain features are similar with other species in the infraorder Caviomorpha. The brain of the pacarana resembles the brains of the Patagonian mara, capybara and guinea pig. The common porcupine presents a different shape to the brain. The guinea pig and the common porcupine are lissencephalic. The animals that present sulci in the brain, follow this order from more to less girencephalic: capybara, mara and pacarana. The rhinal fissure is important because it delimits the rhinencephalon and it is present in all the animals mentioned above. In the mara, the colliculi are exposed in dorsal and lateral views, however, this does not happen for the pacarana. The cerebellum is similar in these species, but the flocculus is more pronounced in the guinea pig. The brain of Caviomorpha species is supplied only by the vertebrobasilar system in most species analyzed, as in the capybara, guinea pig, coypus, mara, chinchilla, degu and in pacarana, where the absence of the carotid artery was observed. In some species the rostral cerebral artery anastomosis in a single branch that runs towards the corpus callosum (degu, capybara, chinchilla and coypus), but in the pacarana the rostral cerebral artery is present in both left and right sides, then branching towards the corpus callosum and the splenial sulcus. In summary, the pacarana presents brain features similar to other Caviomorpha, with some specific species variation.

Main lesions in the central nervous system of dogs due to Leishmania infantum infection

BackgroundCanine visceral leishmaniasis (CVL) is endemic in São Luís Maranhão/Brazil and it leads a varied clinical picture, including neurological signs.ResultsHistopathological evaluation showed that 14 dogs exhibited pathological alterations in at least one of the analyzed areas. Of these, mononuclear inflammatory reaction was the most frequent, although other lesions, such as hemorrhage, chromatolysis and gliosis were also observed. The presence of L. infantum amastigotes was confirmed in eight dogs, identified in four regions: telencephalon, hippocampus, thalamus and caudal colliculus, but only one presented neurological signs. Polymerase chain reaction results detected the DNA of the parasite in 11 samples from seven dogs. The positive areas were the telencephalon, thalamus, hippocampus, cerebellum, caudal and rostral colliculus.ConclusionThese results reveal that during canine visceral leishmaniasis, the central nervous system may display some alterations, without necessarily exhibiting clinical neurological manifestations. In addition, the L. infantum parasite has the ability to cross the blood brain barrier and penetrate the central nervous system.

Comparative morphology of the visual and auditory reflex centres in the African grasscutter (Thryonomys swinderianus – Temminck, 1827)

The African grasscutter is a nocturnal rodent, currently bred as a minilivestock, and research model. The present study was aimed at describing the structure of the auditory and visual reflex centres, with a view to understanding the nocturnal behaviour of the rodent. The rostral and caudal colliculi of the mesencephalic tectum were harvested from neonate, juvenile and adult African grasscutters and subjected to basic neuro-anatomical techniques. On each postnatal period, the corpora quadrigemina was bound rostrally by the 3rd ventricle and caudally by the 4th ventricle, and the caudal colliculus was grossly bigger than the rostral colliculus. The heights of the rostral and caudal colliculi in the neonates were 6.38 ± 0.28 mm and 8.78 ± 0.08 mm, respectively, and the difference was significant (P < 0.05). The values in the juveniles were 5.94 ± 0.21 mm and 11.45 ± 0.17 mm, respectively, and the difference was significant (P < 0.05). The values in the adults were 8.08 ± 0.35 mm and 16.16 ± 0.30 mm, respectively, and the difference was also significant (P < 0.05). The relative weight of rostral colliculus in the adult was significantly (P < 0.05) higher than that of the neonates, but not the juveniles. The relative weight of the caudal colliculus in the adults was significantly (P < 0.05) higher than that of the juveniles. In conclusion, the relatively bigger caudal colliculi, than the rostral colliculi, observed at all postnatal periods studied, suggests a more acute auditory than visual ability in the African grasscutter.

Collagenous choristoma at the cerebellar peduncle of a Nelore bull

Choristomas are mature normal tissues in abnormal anatomical positions. Reports in domestic animals are uncommon to rare, usually restricted to cattle, with the proliferation of different tissues in various locations, such as subcutaneous tissue, thoracic cavity, retroperitoneal and ocular regions. No age range is predominantly affected, but there are more reports in young cattle. The Laboratory of Veterinary Pathology at the Universidade Federal do Rio Grande do Sul received a brainstem sample of a bull, Nelore breed, 5 years old, from the project of Supplementary Diagnostic Methods of Transmissible Spongiform Encephalopathies (TSEs). The animal presented recumbency at the time of slaughter; was alert, with a complete fracture to the right femur and without neurological signs. On gross examination, there was a white oval firm mass, located caudally to the left caudal colliculus, on the left cerebellar peduncle. In the microscopic examination, there was a well-demarcated area, unencapsulated and composed predominantly of connective tissue fibers (collagen). Immunohistochemical examination for glial fibrillary acidic protein was negative. Due to the gross and microscopic characteristics, a diagnosis of collagenous choristoma at the cerebellar peduncle was established, since the presence of collagen within the brain tissue itself is abnormal.

Neurohistopathological findings of the effects of amprolium on the brain and spinal cord changes in the a animal model: An experimental study

The aim of the study was to evaluate the polioencephalomalacia induced with amprolium in goats: pathologic changes of the central nervous system. Eight apparently healthy goats of 6 to 9 weeks of age were drenched with amprolium (200 mg/kg body weight) till the development of clinical signs. Three goats of the same age group were drenched with tap water only and these served as controls. Amprolium drenched goats were allowed to die after the onset of clinical signs and control goats were euthanised after the death of amprolium fed goats. At the time of development of typical clinical signs of cerebrocortical necrosis (CCN) the goats were killed and necropsied and a complete histopathologic examination was performed. At necropsy of the four goats, large necrotic lesion was found in the cerebral cortex, and tissue thiamine levels decreased significantly, especially in cerebrum and cerebellum. However, the brain as a whole in all experimental animals, exhibited moderate to severe congestion, oedema and numerous small yellowish foci of varying sizes scattered on the surface of the cerebral hemispheres.Microscopic changes in the brain were limited to gray matter structures of cerebral and cerebellar cortex, caudal colliculi of mid brain, thalamus, cerebellum and spinal cord. There was shrinkage of neurons, perivascular and pericellular edema, necrosis of neurons, satellitosis, glial nodule, gliosis, middle laminar necrosis and deep laminar edema. Blood vessel walls were thickened due to hypertrophy and hyperplasia of endothelial and adventitial cells. Swollen and prominent capillary epithelium, satellitosis, presence of ghost cells, gliosis and perivascular cuffing were also observed but only in some of the animals. In the cerebellar cortex, there was degeneration of Purkinje cells. The caudal colliculi of mid brain showed bilateral malacia. To the best of our knowledge, these researchers questioned the hypothesis that the amprolium could be the major factor causing polioencephalomalacia. This is the first documentation of Amprolium-Induced cerebrocortical necrosis on goat in Iran.

High resolution MRI anatomy of the cat brain at 3Tesla

Feline models of neurologic diseases, such as lysosomal storage diseases, leukodystrophies, Parkinson's disease, stroke and NeuroAIDS, accurately recreate many aspects of human disease allowing for comparative study of neuropathology and the testing of novel therapeutics. Here we describe in vivo visualization of fine structures within the feline brain that were previously only visible post mortem. 3Tesla MR images were acquired using T1-weighted (T1w) 3D magnetization-prepared rapid gradient echo (MPRAGE) sequence (0.4mm isotropic resolution) and T2-weighted (T2w) turbo spin echo (TSE) images (0.3mm×0.3mm×1mm resolution). Anatomic structures were identified based on feline and canine histology. T2w high resolution MR images with detailed structural identification are provided in transverse, sagittal and dorsal planes. T1w MR images are provided electronically in three dimensions for unrestricted spatial evaluation. Many areas of the feline brain previously unresolvable on MRI are clearly visible in three orientations, including the dentate, interpositus and fastigial cerebellar nuclei, cranial nerves, lateral geniculate nucleus, optic radiation, cochlea, caudal colliculus, temporal lobe, precuneus, spinocerebellar tract, vestibular nuclei, reticular formation, pyramids and rostral and middle cerebral arteries. Additionally, the feline brain is represented in three dimensions for the first time. These data establish normal appearance of detailed anatomical structures of the feline brain, which provide reference when evaluating neurologic disease or testing efficacy of novel therapeutics in animal models.

Neurohistopathological Findings of the Effects of Amprolium on the Brain and Spinal Cord Changes in the a Animal Model

The aim of the study was to evaluate the polioencephalomalacia induced with amprolium in goats: pathologic changes of the central nervous system. Eight apparently healthy goats of 6 to 9 weeks of age were drenched with amprolium (200 mg/kg body weight) till the development of clinical signs. Three goats of the same age group were drenched with tap water only and these served as controls. Amprolium drenched goats were allowed to die after the onset of clinical signs and control goats were euthanised after the death of amprolium fed goats. At the time of development of typical clinical signs of Cerebrocortical Necrosis (CCN) the goats were killed and necropsied and a complete histopathologic examination was performed. At necropsy of the four goats, large necrotic lesion was found in the cerebral cortex, and tissue thiamine levels decreased significantly, especially in cerebrum and cerebellum. However, the brain as a whole in all experimental animals, exhibited moderate to severe congestion, oedema and numerous small yellowish foci of varying sizes scattered on the surface of the cerebral hemispheres. Microscopic changes in the brain were limited to gray matter structures of cerebral and cerebellar cortex, caudal colliculi of mid brain, thalamus, cerebellum and spinal cord. There was shrinkage of neurons, perivascular and pericellular edema, necrosis of neurons, satellitosis, glial nodule, gliosis, middle laminar necrosis and deep laminar edema. Blood vessel walls were thickened due to hypertrophy and hyperplasia of endothelial and adventitial cells. Swollen and prominent capillary epithelium, satellitosis, presence of ghost cells, gliosis and perivascular cuffing were also observed but only in some of the animals. In the cerebellar cortex, there was degeneration of Purkinje cells. The caudal colliculi of mid brain showed bilateral malacia. To the best of our knowledge, these researchers questioned the hypothesis that the amprolium could be the major factor causing polioencephalomalacia. This is the first documentation of Amprolium-Induced cerebrocortical necrosis on goat in Iran.

Alterações no SNC e morfometria cerebelar de bovinos intoxicados experimentalmente por Solanum paniculatum

Algumas espécies de Solanum causam intoxicações em ruminantes caracterizadas clinicamente por desordens cerebelares e microscopicamente como doença do depósito lisossomal. Não há lesões de necropsia específicas e microscopicamente ocorrem vacuolização e perda de neurônios de Purkinje. Por ser Solanum paniculatum a espécie de ocorrência na região Nordeste, sendo responsável pelos surtos de intoxicação espontânea descrito no Estado de Pernambuco foi realizado um delineamento experimental para caracterizar o quadro clínico-patológico da intoxicação. Foram usados cinco bovinos, sendo quatro no grupo experimental (GE) e um animal no controle (GC), de seis meses de idade, sem raça definida, com peso de 120 Kg, mantidos em baias durante cinco meses na Clínica de Bovinos de Garanhuns/UFRPE. Os animais receberam a planta, colhida nas propriedades em que ocorreram os surtos naturais, na dosagem de 5g/kg/PV/dia da planta dessecada misturada na ração por ingestão natural. Semanalmente realizou-se o Head Raising Test para determinar os sinais cerebelares e quando positivo os animais foram submetidos à colheita de sangue e do líquido céfalo-raquidiano e em seguida foi feito à eutanásia. O SNC e a rete mirabile foram fixados em formol a 10% tamponado, processados rotineiramente e corados pela hematoxilina e eosina para avaliação histopatológica. Foi realizada análise morfométrica das lesões cerebelares. Para avaliação dos resultados laboratoriais utilizou-se análise descritiva e em relação à morfometria, empregou-se o teste T de Student (p&lt;0.05) na contagem de células de Purkinje e para a espessura da camada molecular do cerebelo o teste de Mann Whitney, com nível de 5% de significância. Três animais apresentaram sinais de intoxicação com tempo em média de 90 dias e um com 155 dias. Os sinais clínicos observados foram ataques convulsivos transitórios, e distúrbios do equilíbrio. Na necropsia não foram encontradas lesões específicas da intoxicação. Não houve alterações no hemograma e no líquido céfalo-raquidiano causado pela planta. No histopatológico havia principalmente vacuolização fina do pericário e perda de células de Purkinje, com degeneração Walleriana e esferóides axonais na camada granular e na substância branca medular, com proliferação dos astrócitos de Bergman. Vacuolização e necrose neuronal também foram observadas no óbex, pedúnculos cerebelares e colículos rostral e caudal e raramente no tálamo, núcleos da base, hipocampo e medula oblonga. Na análise morfométrica não houve diferença significativa (p&lt;0,05) entre o número de células de Purkinje e a espessura da camada molecular entre o GE e GC, demonstrando que apesar dos bovinos desenvolverem quadro clínico da intoxicação e alterações histopatológicas acentuadas, mas nestas condições experimentais não ocorreram alteração morfométricas significativas em relação ao GC. Sugerindo que há necessidade de um tempo de administração maior da planta para o aparecimento de lesões mais acentuadas como as que ocorrem em casos naturais. Os resultados laboratoriais de sangue e do líquido céfalo-raquidiano não refletem alterações relacionadas à intoxicação pela planta.

FDG Uptake of Normal Canine Brain Assessed by High-Resolution Research Tomography-Positron Emission Tomography and 7 T-Magnetic Resonance Imaging

The purpose of this study was to assess the normal distribution of (18)F-fluoro-2-deoxy-D-glucose (FDG) uptake of canine brain structures using a high-resolution research tomography-positron emission tomography (HRRT-PET) and 7 T-magnetic resonance imaging (MRI) fusion system. FDG-PET and T2-weighted MRI of the brain were performed on 4 healthy laboratory beagle dogs. On MRI, regions of interests (ROIs) were manually drawn over 51 intracranial structures, including nine gross structures and 42 detailed structures. Relative standard uptake value ratio (rSUV=SUV of ROI/SUV of whole brain) was calculated for each ROI. The HRRT-PET and 7 T-MRI fusion imaging system demonstrated significant differences in glucose metabolism among various intracranial structures. Among gross structures, the midbrain and the pons and medulla oblongata had the highest uptake (rSUV: 1.12 ± 0.03) and lowest uptake (rSUV: 0.90 ± 0.06) of FDG, respectively. When rSUVs were calculated on detailed regions, the caudal colliculus and the longitudinal fibers of pons had the highest (rSUV: 1.62 ± 0.05) and the lowest (rSUV: 0.63 ± 0.03) glucose metabolism, respectively. Because the high resolution of PET-MRI fusion images provided clearly identifiable metabolic activities of canine brain, the HRRT-PET and 7 T-MRI fusion imaging might be a good tool for evaluation of intracranial diseases in canines.

Endocranial morphology of Labidolemur kayi (Apatemyidae, Apatotheria) and its relevance to the study of brain evolution in Euarchontoglires

ABSTRACT Apatemyids are known from the Paleocene and Eocene of Europe, and the Paleocene to Oligocene of North America, and may share a special relationship with Euarchontoglires. The only endocast previously described for an apatemyid pertains to Carcinella sigei from the late Eocene of France. Here we present a composite virtual endocast of Labidolemur kayi derived from high-resolution X-ray computed tomography data, based on partial crania from the late Paleocene (Clarkforkian) and early Eocene (Wasatchian) of the Clarks Fork Basin, Wyoming. Like C. sigei, L. kayi had voluminous, transversely expansive olfactory bulbs, accounting for approximately 12–15% of the endocranial volume. This is similar to Cretaceous eutherians, but contrasts with the relatively smaller olfactory bulbs in both the basal gliran Rhombomylus turpanensis and in primitive primates (Ignacius graybullianus, Microsyops annectens). Similar to R. turpanensis, I. graybullianus, and the inferred ancestral condition for Microsyops, but unlike C. sigei, L. kayi exhibited exposed caudal colliculi, supporting the inference that this condition was primitive for Euarchontoglires and Euarchonta. The cranial capacity of L. kayi is estimated at 0.5–0.6 cc, yielding encephalization quotient (EQ) estimates of 0.23–0.28 or 0.42–0.50 depending on the equation used. These values are much lower than estimates for C. sigei, suggesting significant increase occurred in brain size in Apatemyidae, perhaps related to elaborations in the family's specialized manual extractive feeding regime. Similarities with primitive primates in EQ and the inferred position of the rhinal sulcus may allow for inferences about encephalization and neocorticalization in the common ancestor of Euarchontoglires.