Morfologia e morfometria do encéfalo de avestruz (Struthio camelus) / Morphology and morphometry of the ostrich encephalus (Struthio camelus)

O avestruz africano é uma ave ratita da família Struthionidae. As características anatômicas do encéfalo do avestruz foram investigadas neste artigo. Vinte encéfalos de avestruzes adultos (dez machos e dez fêmeas), fixados em formaldeído a 10%, foram analisados neste estudo. Foram obtidas as medidas do encéfalo: comprimento e largura total do encéfalo, comprimento, largura e altura dos hemisférios cerebrais direito e esquerdo, comprimento e largura do cerebelo, comprimento e largura dos lobos ópticos direito e esquerdo. Também foram aferidos o comprimento e a largura do crânio. Os resultados para cada variável foram expressos em média e em desvio padrão. Através do teste t de Student não-pareado as variáveis foram comparadas entre os sexos e entre os antímeros. Considerou-se p<0,05 como significante. O comprimento e largura do encéfalo dos machos foram de 5,57 cm ± 0,23 cm e de 4,19 cm ± 0,16 cm, respectivamente. Nas fêmeas o comprimento e largura do encéfalo foram de 5,56 cm ± 0,23 cm e de 4,18 cm ± 0,16 cm respectivamente. O comprimento do hemisfério cerebral direito foi de 3,41 cm ± 0,13 cm nos machos e de 3,39 cm ± 0,12 cm nas fêmeas, já no esquerdo foi de 3,35 cm ± 0,14 cm nos machos e de 3,34 cm ± 0,05 cm nas fêmeas. A largura do hemisfério cerebral direito foi de 2,27 cm ± 0,17 cm nos machos e de 2,25 ± 0,14 cm nas fêmeas, e do esquerdo foi de 2,25 cm ± 0,11 cm nos machos e de 2,27 cm ± 0,11 cm nas fêmeas. A altura do hemisfério cerebral direito foi de 2,08 cm ± 0,23 cm nos machos e de 2,07 cm ± 0,21 cm nas fêmeas e do hemisfério cerebral esquerdo foi de 2,05 cm ± 0,22 cm nos machos e de 2,05 cm ± 0,22 nas fêmeas. O comprimento do cerebelo foi de 2,45 cm ± 0,32 cm nos machos e de 2,44 cm ± 0,32 cm nas fêmeas, e sua largura foi de 1,59 cm ± 0,16 cm nos machos e de 1,58 cm ± 0,15 cm nas fêmeas. O comprimento do lobo óptico direito foi de 1,30 cm ± 0,06 nos machos e de 1,30 cm ± 0,06 cm nas fêmeas, já o comprimento do lobo óptico esquerdo foi de 1,24 cm ± 0,07 cm nos machos e de 1,23 cm ± 0,67 cm nas fêmeas. A largura do lobo óptico direito foi de 1,08 cm ± 0,07 cm nos machos e de 1,08 cm ± 0,07 cm nas fêmeas e largura do lobo óptico esquerdo foi de 1,08 cm ± 0,07 cm nos machos e de 1,08 cm ± 0,07 cm nas fêmeas. A superfície do cérebro do avestruz é lisa sem qualquer giro ou sulco. A média do comprimento dos crânios dos machos é maior que a das fêmeas. Em relação aos 20 encéfalos analisados o lobo óptico direito é maior que o esquerdo. Houve correlação linear positiva entre a largura do crânio com a largura do cerebelo.

The african ostrich is a ratite bird in the family Struthionidae. The anatomical features of the African ostrich brain were investigated in this study. Twenty adult ostrich heads (10 males and 10 females), fixed in 10% formaldehyde, were analyzed in this study. The measures of the brain were obtained: length and total width of the brain, length, width and height of the right and left cerebral hemispheres, length and width of the cerebellum, length and width of the right and left optical lobes. The length and width of the skull were also measured. Results for each variable were expressed as mean and standard deviation. Through unpaired Student's ttest the variables were compared between sexes and between antimers. Statistical significance was considered as p<0,05. The length and width of the male encephalus was 5.57 ± 0.23 cm and 4.19 ± 0.16, respectively. In females, the length and width of the encephalus were 5.56 ± 0.23 and 4.18 ± 0.16 respectively. The length of the right cerebral hemisphere was 3.41 ± 0.13 in males and 3.39 ± 0.12 in females, while in the left it was 3.35 ± 0.14in males and 3.34 ± 0.05 in females. The width of the right cerebral hemisphere was 2.27 ± 0.17 in males and 2.25 ± 0.14 in females, and the left was 2.25 ± 0.11 in males and 2.27 ± 0.11 in females. The height of the right cerebral hemisphere was 2.08 ± 0.23 in males and 2.07 ± 0.21 in females and the left cerebral hemisphere was 2.05 ± 0.22 in males and 2.05 ± 0.22 in females. The length of the cerebellum was 2.45 ± 0.32 in males and 2.44 ± 0.32 in females, and its width was 1.59 ± 0.16 in males and 1.58 ± 0.15 in females. The length of the right optic lobe was 1.30 ± 0.06 in males and 1.30 ± 0.06 in females, while the length of the left optic lobe was 1.24 ± 0.07 in males and 1.23 ± 0.67 in females. The width of the right optic lobe was 1.08 ± 0.07 in males and 1.08 ± 0.07 in females and the width of the left optic lobe was 1.08 ± 0.07 in males and 1.08 ± 0.07 in females. The surface of the ostrich brain is smooth without any gyrus or sulcus. The average length of the skulls of males is greater than that of females. In relation to the 20 encephalus analyzed, the right optic lobe is larger than the left. There was a positive linear correlation between the width of the skull and the width of the cerebellum.

Morfologia e morfometria do encéfalo de avestruz (Struthio camelus) / Morphology and morphometry of the ostrich encephalus (Struthio camelus)

O avestruz africano é uma ave ratita da família Struthionidae. As características anatômicas do encéfalo do avestruz foram investigadas neste artigo. Vinte encéfalos de avestruzes adultos (dez machos e dez fêmeas), fixados em formaldeído a 10%, foram analisados neste estudo. Foram obtidas as medidas do encéfalo: comprimento e largura total do encéfalo, comprimento, largura e altura dos hemisférios cerebrais direito e esquerdo, comprimento e largura do cerebelo, comprimento e largura dos lobos ópticos direito e esquerdo. Também foram aferidos o comprimento e a largura do crânio. Os resultados para cada variável foram expressos em média e em desvio padrão. Através do teste t de Student não-pareado as variáveis foram comparadas entre os sexos e entre os antímeros. Considerou-se p<0,05 como significante. O comprimento e largura do encéfalo dos machos foram de 5,57 cm ± 0,23 cm e de 4,19 cm ± 0,16 cm, respectivamente. Nas fêmeas o comprimento e largura do encéfalo foram de 5,56 cm ± 0,23 cm e de 4,18 cm ± 0,16 cm respectivamente. O comprimento do hemisfério cerebral direito foi de 3,41 cm ± 0,13 cm nos machos e de 3,39 cm ± 0,12 cm nas fêmeas, já no esquerdo foi de 3,35 cm ± 0,14 cm nos machos e de 3,34 cm ± 0,05 cm nas fêmeas. A largura do hemisfério cerebral direito foi de 2,27 cm ± 0,17 cm nos machos e de 2,25 ± 0,14 cm nas fêmeas, e do esquerdo foi de 2,25 cm ± 0,11 cm nos machos e de 2,27 cm ± 0,11 cm nas fêmeas. A altura do hemisfério cerebral direito foi de 2,08 cm ± 0,23 cm nos machos e de 2,07 cm ± 0,21 cm nas fêmeas e do hemisfério cerebral esquerdo foi de 2,05 cm ± 0,22 cm nos machos e de 2,05 cm ± 0,22 nas fêmeas. O comprimento do cerebelo foi de 2,45 cm ± 0,32 cm nos machos e de 2,44 cm ± 0,32 cm nas fêmeas, e sua largura foi de 1,59 cm ± 0,16 cm nos machos e de 1,58 cm ± 0,15 cm nas fêmeas. O comprimento do lobo óptico direito foi de 1,30 cm ± 0,06 nos machos e de 1,30 cm ± 0,06 cm nas fêmeas, já o comprimento do lobo óptico esquerdo foi de 1,24 cm ± 0,07 cm nos machos e de 1,23 cm ± 0,67 cm nas fêmeas. A largura do lobo óptico direito foi de 1,08 cm ± 0,07 cm nos machos e de 1,08 cm ± 0,07 cm nas fêmeas e largura do lobo óptico esquerdo foi de 1,08 cm ± 0,07 cm nos machos e de 1,08 cm ± 0,07 cm nas fêmeas. A superfície do cérebro do avestruz é lisa sem qualquer giro ou sulco. A média do comprimento dos crânios dos machos é maior que a das fêmeas. Em relação aos 20 encéfalos analisados o lobo óptico direito é maior que o esquerdo. Houve correlação linear positiva entre a largura do crânio com a largura do cerebelo.(AU)

The african ostrich is a ratite bird in the family Struthionidae. The anatomical features of the African ostrich brain were investigated in this study. Twenty adult ostrich heads (10 males and 10 females), fixed in 10% formaldehyde, were analyzed in this study. The measures of the brain were obtained: length and total width of the brain, length, width and height of the right and left cerebral hemispheres, length and width of the cerebellum, length and width of the right and left optical lobes. The length and width of the skull were also measured. Results for each variable were expressed as mean and standard deviation. Through unpaired Student's ttest the variables were compared between sexes and between antimers. Statistical significance was considered as p<0,05. The length and width of the male encephalus was 5.57 ± 0.23 cm and 4.19 ± 0.16, respectively. In females, the length and width of the encephalus were 5.56 ± 0.23 and 4.18 ± 0.16 respectively. The length of the right cerebral hemisphere was 3.41 ± 0.13 in males and 3.39 ± 0.12 in females, while in the left it was 3.35 ± 0.14in males and 3.34 ± 0.05 in females. The width of the right cerebral hemisphere was 2.27 ± 0.17 in males and 2.25 ± 0.14 in females, and the left was 2.25 ± 0.11 in males and 2.27 ± 0.11 in females. The height of the right cerebral hemisphere was 2.08 ± 0.23 in males and 2.07 ± 0.21 in females and the left cerebral hemisphere was 2.05 ± 0.22 in males and 2.05 ± 0.22 in females. The length of the cerebellum was 2.45 ± 0.32 in males and 2.44 ± 0.32 in females, and its width was 1.59 ± 0.16 in males and 1.58 ± 0.15 in females. The length of the right optic lobe was 1.30 ± 0.06 in males and 1.30 ± 0.06 in females, while the length of the left optic lobe was 1.24 ± 0.07 in males and 1.23 ± 0.67 in females. The width of the right optic lobe was 1.08 ± 0.07 in males and 1.08 ± 0.07 in females and the width of the left optic lobe was 1.08 ± 0.07 in males and 1.08 ± 0.07 in females. The surface of the ostrich brain is smooth without any gyrus or sulcus. The average length of the skulls of males is greater than that of females. In relation to the 20 encephalus analyzed, the right optic lobe is larger than the left. There was a positive linear correlation between the width of the skull and the width of the cerebellum.(AU)

Anatomia macroscópica e vascularização do encéfalo de emas (Rhea americana americana) / Macroscopic anatomy and brain vascularization in the greater rhea (Rhea americana americana)

Background: The Rhea americana americana is a wild bird belonging to the group of Ratites, and is important from the scientific point of view given their adaptability to captivity. Considering that information about its morphology is important for the viability of domesticating the species, the aim of this study was to macroscopically identify the brain regions, as well as the cerebral arteries and the cerebral arterial circuit in order to establish the cerebral vascular pattern and systematization.Materials, Methods & Results: Twenty one brains from young and adult Greater Rheas of both sexes were used from animals that had died due to natural causes and were then kept in a freezer. The specimens were thawed and incised in the cervical region to allow exposure of the left common carotid artery, which was cannulated. The vascular system was rinsed with 0.9% saline solution, then perfused with latex Neoprene 650 stained with red pigment. The animals were subsequently fixed in 3.7% aqueous formaldehyde solution for 72 h, and then they were dissected by removing the bones from the skull cap. The brains were analyzed, and the structures were identified, photographed, schematized and denominated. Morphometric measurements were performed on the basilar and cerebellar ventral caudal arteries, recording the values of length and width in millimeters with the aid of a digital caliper. The brain was divided into: telencephalon, diencephalon, brainstem and cerebellum; while externally, the observed structures are: olfactory bulbs, optical lobes, optic nerves, optic chiasm, pituitary and pineal glands. Vascularization was performed by the following arteries: ventral spinal artery, basilar artery, ventricular cerebellar arteries, medium ventricular cerebellar arteries, caudal branches of the carotid arteries of the brain, ventral mesencephalic artery, cerebral caudal arteries, rostral branches of the carotid arteries of the brain, middle cerebral arteries,[...]

Anatomia macroscópica e vascularização do encéfalo de emas (Rhea americana americana) / Macroscopic anatomy and brain vascularization in the greater rhea (Rhea americana americana)

Background: The Rhea americana americana is a wild bird belonging to the group of Ratites, and is important from the scientific point of view given their adaptability to captivity. Considering that information about its morphology is important for the viability of domesticating the species, the aim of this study was to macroscopically identify the brain regions, as well as the cerebral arteries and the cerebral arterial circuit in order to establish the cerebral vascular pattern and systematization.Materials, Methods & Results: Twenty one brains from young and adult Greater Rheas of both sexes were used from animals that had died due to natural causes and were then kept in a freezer. The specimens were thawed and incised in the cervical region to allow exposure of the left common carotid artery, which was cannulated. The vascular system was rinsed with 0.9% saline solution, then perfused with latex Neoprene 650 stained with red pigment. The animals were subsequently fixed in 3.7% aqueous formaldehyde solution for 72 h, and then they were dissected by removing the bones from the skull cap. The brains were analyzed, and the structures were identified, photographed, schematized and denominated. Morphometric measurements were performed on the basilar and cerebellar ventral caudal arteries, recording the values of length and width in millimeters with the aid of a digital caliper. The brain was divided into: telencephalon, diencephalon, brainstem and cerebellum; while externally, the observed structures are: olfactory bulbs, optical lobes, optic nerves, optic chiasm, pituitary and pineal glands. Vascularization was performed by the following arteries: ventral spinal artery, basilar artery, ventricular cerebellar arteries, medium ventricular cerebellar arteries, caudal branches of the carotid arteries of the brain, ventral mesencephalic artery, cerebral caudal arteries, rostral branches of the carotid arteries of the brain, middle cerebral arteries,[...](AU)

Hematological and morphometric differences of blood cells from rheas, Rhea americana (Struthioniformes: Rheidae) on two conservation farms / Diferenças hematológicas e morfométricas de células sanguineas de emas, Rhea americana (Struthioniformes: Rheidae) em dois criatórios conservacionistas

Today, blood tests are an indispensable tool in avian medicine. This study aimed to describe and compare hematological and morphometric data of erythrocytes, leukocytes and thrombocytes of rhea, Rhea americana. To do so, 58 rheas of both sexes on two farms, one in Cachoeiro do Itapemirim, Espيrito Santo (ES), and the other in Sمo Carlos, Sمo Paulo (SP), were selected. Blood samples were taken and their RBC counts, PCV and Hb levels were determined and used in hematimetric index calculations. The total and differentiated leukocyte counts and the TPP and fibrinogen serum levels were also obtained. The results from the two farms analyzed were compared by means of the t test. There were differences in the parameters of the erythrocyte series between the two flocks because of a process of hypochromic macrocytic anemia observed among the rheas in ES. The values for the erythrocyte series and indexes were: RBC, 2.81 ± 0.15 x106/l; PCV, 44.20 ± 2.86%; Hb, 12.12 ± 0.74 g/dL; MCV, 15.75 ± 0.89 fL; MCH, 43.18 ± 1.82 pg; and MCHC, 27.44 ± 0.80 g/dL. The values for the leukocyte series were: WBC, 12,072 ± 4116 /L; heterophils, 64.10 ± 9.90%; eosinophils, 2.05 ± 2.06%; monocytes, 6.40 ± 2.99%; lymphocytes, 26.93 ± 9.62%; and basophils, 0.52 ± 1.27%. These can all be suggested as references for rheas reared in Brazil. Statistical differences were observed in erythrocyte length measurements, which were higher in the rheas in SP than in those in ES. Regarding width, the heterophils, lymphocytes and monocytes of the birds in ES were statistically greater than those of the birds in SP. It was concluded that rheas may exhibit morphometric alterations to blood cells and differences in blood elements according to the type of management to which they are subjected.(AU)

Atualmente exames de sangue são ferramentas indispensáveis na medicina aviária. Este estudo teve como objetivo descrever e comparar valores hematológicos e morfométricos de eritrócitos, leucócitos e trombócitos de emas, Rhea americana. Para isso, foram selecionadas 58 emas de ambos os sexos de dois criatórios, um em Cachoeiro do Itapemirim, Espírito Santo (ES) e o outro em São Carlos, São Paulo (SP). Amostras de sangue foram coletadas e realizadas a hematimetria, Hto e dosagem de Hb que foram utilizados nos cálculos dos índices hematimétricos. Também foram efetuadas as contagens total e diferencial de leucócitos, além da dosagem de proteínas total e do fibrinogênio séricos. Os resultados referentes às duas propriedades analisadas foram comparados pelo Teste t. Ocorreram diferenças nos parâmetros da série vermelha entre as aves dos dois criatórios devido a um processo de anemia macrocítica hipocrômica observado nas emas do ES. Os valores para a série vermelha e índices hematimétricos como: hematimetria, 2,81±0,15 x106/μl; Hto, 44,20±2,86%; Hb, 12,12±0,74 g/dL; VCM, 15,75±0,89 fL; HCM, 43,18±1,82 pg; CHCM, 27,44±0,80, além dos valores da série branca como: leucometria total, 12.072±4.116/μL, heterofilo, 64,10±9,90%, eosinófilo, 2,05±2,06%, monócito, 6,40±2,99%, linfócito, 26,93±9,62%, basófilo, 0,52±1,27% foram sugeridos como os de referência para as emas criadas no Brasil. Diferenças estatísticas foram observadas no comprimento de eritrócitos, o qual estava maior nas emas de SP do que aquelas do ES. Em relação à largura, os heterófilos, linfócitos e monócitos das aves do ES foram estatisticamente maior do que aquelas das aves de SP. Concluiu-se que emas podem apresentar alterações morfométricas de células sanguíneas e diferenças nos elementos do sangue de acordo com o tipo de manejo a que são submetidos.(AU)

Comparative morphology of the species of Libyostrongylus and Codiostomum, parasites from ostriches, Struthio camelus, with a identification key to the species / Morfologia Comparativa das espécies de Libyostrongylus e Codiostomum, parasitas de avestruzes, Struthio camelus, com uma chave para identificação das espécies

One of the most common problems in breeding of ostriches in captivity is the control of parasitic diseases. This work presents keys for the identification of adult nematodes and infective larvae by morphologic and morphometric characteristics. These keys will allow the scientific community to identify the species that infect the ostriches either based on the characteristics of the posterior end of the infective larvae found through a simple fecal exam or by observing the morphology and morphometry of adult worms recovered during necropsies. These keys will facilitate ecological and systematic studies, as well as increase the understanding of the epidemiology of these parasitosis in ostriches.

Um dos problemas mais comuns na criação de avestruzes em cativeiro é o controle das doenças parasitárias. Este trabalho apresenta chaves para a identificação de Nematoda adultos e larvas infectantes através de caracteres morfológicos e morfométricos. Essas chaves de identificação permitirão à comunidade científica o diagnóstico das espécies que infectam as avestruzes com base nas características da extremidade posterior das larvas infectantes encontradas por meio de simples exames fecais ou pela observação da morfologia e morfometria dos espécimes adultos recuperados durante necropsia. Dessa forma, as chaves de identificação facilitarão os estudos ecológicos e sistemáticos, bem como a melhor compreensão da epidemiologia dessas infecções em avestruzes.

MORFOLOGIA DO ENCÉFALO DE EMAS (Rhea americana americana LINNAEUS, 1758)

Objetivou-se identificar macroscopicamente as regiões do encéfalo, bem como, as arterias cerebrais e o circuito arterioso cerebral, de modo a estabelecer um padrão vascular e sua sistematização, assim como, quantificar sua morfometria e estereologia. Para tanto, foram utilizados 21 encéfalos de emas, sendo 13 fêmeas e 2 machos (idades de 18 meses) e, 4 fêmeas e 2 machos (idades de 2 meses) para o estudo da vascularização e 22 encéfalos, sendo 2 fêmeas e 1 macho (1 mês), 1 fêmea e 2 machos (2 meses), 2 fêmeas e 1 macho (3, 4, 5 e 6 meses) e, 2 fêmeas e 2 machos (18 meses) para as análises de morfometria e estereologia. Os animais foram descongelados e incisados no plano sagital, na região cervical, de modo a expor a artéria carótida comum esquerda, a qual foi canulada e o sistema vascular lavado com solução salina a 0,9%, e logo após, perfundido com látex Neoprene 650, corado com pigmento vermelho, de forma a permitir uma melhor visualização das artérias. Já para o estudo morfométrico e estereológico, as carótidas foram canuladas e perfundidas com cerca de 5-10 ml de formaldeído a 3,7%, a fim de obter a fixação dos encéfalos. Posteriormente, as peças foram imersas em solução aquosa de formaldeído a 3,7%, durante 72 horas, e depois, iniciaram-se as dissecações e remoção dos ossos da calota craniana. Em seguida, os encéfalos foram analisados, sendo as estruturas, identificadas, mensuradas, fotografadas, esquematizadas e nominadas. Quanto à estereologia, os encéfalos foram incluídos em gelatina incolor, mantidos em refrigerador por 24 horas e, posteriormente, obteve-se cortes de 4 mm de espessura. Em seguida, foi removida a gelatina, realizada a coloração de Mainland e efetivada a quantificação do volume cerebral (V= T. a/p. pi). O encéfalo dividiu-se em: telencéfalo, diencéfalo, tronco cerebral e cerebelo e, externamente, observaram-se os bulbos olfatórios, lobos ópticos, nervos ópticos, quiasma óptico, hipófise e pineal. Já quanto ao estudo da vascularização, foram identificadas as artérias: espinhal ventral, basilar, cerebelares ventrais caudais, cerebelares ventrais médias, ramos caudais das artérias carótidas do cérebro, tectais mesencefálicas ventrais, cerebrais caudais, ramos rostrais das artérias carótidas do cérebro, cerebrais médias, cerebroetmoidais, anastomose intercerebral rostral, cerebrais rostrais, etmoidais, oftálmicas internas, inter-hemisférica, hipofisarias, tectais mesencefálicas dorsais, cerebelares dorsais, ramos hemisféricos occipitais, pineais e ramos hemisférios dorsais. O circuito arterioso cerebral apresentou-se de forma fechada, caudalmente e rostralmente em 100% dos espécimes. O encéfalo possuiu mensurações que chegaram até 50,267 mm de comprimento, 41,855 mm de largura, 29,320 mm de altura e 21,774 g de massa. Os lobos ópticos apresentaram valores de comprimento direito (12,647 mm), comprimento esquerdo (12,355 mm), largura direita (11,470 mm), largura esquerda (10,827 mm) e, altura direita (15,495 mm) e altura esquerda (15,122 mm). Já o cerebelo apresentou valores de até 21,462 mm (comprimento), 18,207 mm (largura) e 21,487 mm (altura). Quanto a estereologia do encéfalo, este variou de 33,663 cm³ e 71,971 cm³ (idades de 1-18 meses), respectivamente.

The objective of this study was to identify macroscopically the regions of the brain, as well as the cerebral arteries and the cerebral arterial circuit, in order to establish a vascular pattern and its systematization, as well as to quantify its morphometry and stereology. In order to do so, 21 greater rhea brains were used, 13 females and 2 males (ages 18 months) and 4 females and 2 males (ages 2 months) for the study of vascularization and 22 encephalus, 2 females and 1 male (1 month), 1 female and 2 male (2 months), 2 females and 1 male (3, 4, 5 and 6 months) and 2 females and 2 males (18 months) for morphometry and stereology analyzes. The animals were thawed and incised in the sagittal plane, in the cervical region, in order to expose the left common carotid artery, which was cannulated and the vascular system washed with 0.9% saline, and then perfused with Neoprene latex 650, stained with red pigment, in order to allow a better visualization of the arteries. For the morphometric and stereological study, the carotids were cannulated and perfused with about 5-10 ml of 3.7% formaldehyde in order to obtain the fixation of the brains. Subsequently, the pieces were immersed in aqueous solution of 3.7% formaldehyde for 72 hours, and then, dissections and removal of the bones from the skull cap were initiated. Then, the brains were analyzed, and the structures were identified, measured, photographed, schematized and nominated. As for stereology, the brains were included in colorless gelatin, held in refrigerator for 24 hours, and subsequently cut 4 mm thick. Gelatin was then removed, Mainland stained and quantification of brain volume was performed (V = T. a / p. pi). The brain was divided into: telencephalon, diencephalon, brain stem and cerebellum, and, externally, olfactory bulbs, optic lobes, optic nerves, optic chiasm, pituitary and pineal were observed. Ventral spinal, basilar, ventral cerebellar, mid-ventricular cerebellar, caudal branches of the carotid arteries of the brain, ventral mesencephalic arteries, caudal cerebral arteries, carpal arteries of the brain, middle cerebral arteries , cerebroethmoidal, rostral intercerebral anastomosis, cerebellar rostrais, ethmoidal, internal ophthalmic, interhemispheric, pituitary, dorsal mesencephalic, dorsal cerebellar, occipital, pineal and dorsal hemispherical branches. The cerebral arteriosclerotic circuit was closed, caudally and rostrally in 100% of the specimens. The brain had measurements that reached up to 50.267 mm in length, 41.855 mm in width, 29.320 mm in height and 21.774 g in mass. Optical lobes presented values of right length (12.647 mm), left length (12.355 mm), right width (11.470 mm), left width (10.827 mm) and right height (15.495 mm) and left height (15.112 mm). The cerebellum presented values of up to 21.462 mm (length), 18.207 mm (width) and 21.487 mm (height). As to the stereology of the encephalon, this varied from 33.663 cm³ and 71.971 cm³ (ages 1-18 months), respectively.