Blood supply to the cranial cavity in the patagonian mara (Dolichotis patagonum).

Rodents are the most numerous order of mammals. The literature presents information on the arterial circle of the brain in capybara, the guinea pig of the family Caviidae and many other not so closely related rodent species. Information on the blood supply to the brain is often incomplete and focuses on one pathway in a broader comparative aspect. The supply of oxygen and nutrients to the brain is very important for its proper functioning. The aim of this study is to describe the pathways supplying blood to the cranial cavity and to describe the arterial circle of the brain in the Patagonian mara. The study was conducted on 46 specimens using two methods. The first of them used a stained solution of the chemo-setting acrylic material. The second one, the colored liquid LBS 3060 latex. The arterial circle of the brain is a heart-shaped structure. It is formed by rostral cerebral arteries, caudal communicating arteries and the basilar artery. Blood supplies the arterial circle of the brain in three ways. First one is the basilar artery, which originates from the vertebral arteries. The second one is the internal carotid artery which joins a branch from the external ophthalmic artery. The third is the internal ophthalmic artery, which branches from the external ophthalmic artery.

Historical and current perspectives on blood endothelial cell heterogeneity in the brain.

Dynamic brain activity requires timely communications between the brain parenchyma and circulating blood. Brain-blood communication is facilitated by intricate networks of brain vasculature, which display striking heterogeneity in structure and function. This vascular cell heterogeneity in the brain is fundamental to mediating diverse brain functions and has long been recognized. However, the molecular basis of this biological phenomenon has only recently begun to be elucidated. Over the past century, various animal species and in vitro systems have contributed to the accumulation of our fundamental and phylogenetic knowledge about brain vasculature, collectively advancing this research field. Historically, dye tracer and microscopic observations have provided valuable insights into the anatomical and functional properties of vasculature across the brain, and these techniques remain an important approach. Additionally, recent advances in molecular genetics and omics technologies have revealed significant molecular heterogeneity within brain endothelial and perivascular cell types. The combination of these conventional and modern approaches has enabled us to identify phenotypic differences between healthy and abnormal conditions at the single-cell level. Accordingly, our understanding of brain vascular cell states during physiological, pathological, and aging processes has rapidly expanded. In this review, we summarize major historical advances and current knowledge on blood endothelial cell heterogeneity in the brain, and discuss important unsolved questions in the field.

Brain vascular biology.

The complex development of the brain vascular system can be broken down by embryonic stages and anatomic locations, which are tightly regulated by different factors and pathways in time and spatially. The adult brain is relatively quiescent in angiogenesis. However, under disease conditions, such as trauma, stroke, or tumor, angiogenesis can be activated in the adult brain. Disruption of any of the factors or pathways may lead to malformed vessel development. In this chapter, we will discuss factors and pathways involved in normal brain vasculogenesis and vascular maturation, and the pathogenesis of several brain vascular malformations.

Systematization and description of the internal carotid arteries and their main ramifications at the brain base in turtles (Trachemys scripta elegans).

Thirty turtle brains (Trachemys scripta elegans) were injected with latex to systematize and describe the internal carotid arteries and their main ramifications at the brain base. The internal carotid arteries had one intercarotid anastomosis. At the level of the tuber cinereum, the internal carotid artery bifurcated into its terminal branches, the rostral and the caudal branches. The rostral branch emitted the rostral choroid artery, the orbital artery, and a series of middle cerebral arteries. After giving off the last middle cerebral artery, the rostral branch continued as the rostral cerebral artery in the cerebral longitudinal fissure, and had one anastomosis with its contralateral homologous artery, the rostral communicating artery, making the first rostral closure of the cerebral arterial circle. Next, the rostral cerebral arteries anastomosed forming a rostral interhemispheric artery, making the second rostral closure of the cerebral arterial circle. The internal carotid artery, after emitting its rostral branch, continued caudally as the caudal branch. The caudal branch ran caudally along the ventral surface of the mesencephalic tegmentum, emitted the caudal cerebral artery and the mesencephalic artery, and continued caudomedially while progressively narrowing, and anastomosed with its contralateral homologous artery, forming the basilar artery. The narrower portion also emitted the trigeminal artery. The anastomosis of the caudal branches closed the cerebral arterial circle caudally. The internal carotid arteries exclusively supplied the cerebral arterial circle of the turtle. Anat Rec, 299:1090-1098, 2016. © 2016 Wiley Periodicals, Inc.

Systematization, distribution and territory of the caudal cerebral artery on the brain's surface of the turkey (Meleagris gallopavo) / Sistematização, distribuição e território da artéria cerebral caudal na superfície do encéfalo em peru (Meleagris gallopavo)

Thirty Meleagris gallopavo heads with their neck segments were used. Animals were contained and euthanized with the association of mebezonium iodide, embutramide and tetracaine hydrochloride (T 61, Intervet ) by intravenous injection. The arterial system was rinsed with cold saline solution (15°C), with 5000IU heparin and filled with red-colored latex. The samples were fixed in 20% formaldehyde for seven days. The brains were removed with a segment of cervical spinal cord and after, the dura-mater was removed and the arteries dissected. The cerebral carotid arteries, after the intercarotid anastomosis, were projected around the hypophysis, until they reached the tuber cinereum and divided into their terminal branches, the caudal branch and the rostral branch. The rostral branch was projected rostrolateralwards and gave off, in sequence, two collateral branches, the caudal cerebral and the middle cerebral arteries and the terminal branch was as cerebroethmoidal artery. The caudal cerebral artery of one antimere formed the interhemispheric artery, which gave off dorsal hemispheric branches to the convex surface of both antimeres. Its dorsal tectal mesencephalic branch, of only one antimere, originated the dorsal cerebellar artery. In the interior of the cerebral transverse fissure, after the origin of the dorsal tectal mesencephalic artery, the caudal cerebral artery emitted occipital hemispheric branches, pineal branches and medial hemispheric branches, on both antimeres. The caudal cerebral artery's territory comprehended the entire surface of the dorsal hemioptic lobe, the rostral surface of the cerebellum, the diencephalic structures, the caudal pole and the medial surface of the cerebral hemisphere and in the convex surface, the sagittal eminence except for its most rostral third. Due to the asymmetry found in the caudal cerebral arteries' ramifications, the models were classified into three types and their respective subtypes.

Foram utilizadas 30 cabeças com o segmento de pescoço deMeleagris gallopavo. Os animais foram contidos e eutanasiados com a associação de iodeto de mebezônio, embutramida e cloridrato de tetracaína (T 61 Intervet ), via endovenosa. O sistema arterial foi lavado com solução salina resfriada (15°C), com 5000UI heparina e preenchido com látex corado em vermelho. As peças foram fixadas em formaldeído a 20% por sete dias. O encéfalo foi removido com um segmento de medula espinhal, a dura-máter removida e as artérias dissecadas. As artérias carótidas do cérebro, após a anastomose intercarótica, projetaram-se contornando a hipófise até alcançarem o túber cinéreo e dividiram-se em seus ramos terminais, o ramo caudal e o ramo rostral. O ramo rostral projetou-se rostro-lateralmente emitindo em sequência seus dois principais ramos colaterais, as artérias cerebral caudal e cerebral média terminado-se como artéria cerebroetmoidal. A artéria cerebral caudal de um antímero formava a artéria inter-hemisférica que lançava ramos hemisféricos dosais para a face convexa de ambos os antímeros. Seu ramo tectal mesencefálico dorsal de apenas um antímero originava a artéria cerebelar dorsal. No interior da fissura transversa do cérebro após a origem da artéria tectal mesencefálica dorsal artéria cerebral caudal lançou ramos hemisféricos occipitais, ramos pineais e hemisféricos mediais em ambos os antímeros. O território da artéria cerebral caudal compreendeu toda a superfície do hemi lobo óptico dorsal, a face rostral do cerebelo, as estruturas diencefálicas, o polo caudal e a face medial do hemisfério cerebral e na face convexa do hemisfério cerebral a eminência sagital exceto seu terço mais rostral. Devido à assimetria encontrada nas ramificações das artérias cerebrais caudais, foram classificados os modelos em três tipos com seus respectivos subtipos.

A systematic study of the brain base arteries in the rabbit (Oryctolagus cuniculus) / Sistematização das artérias da base do encéfalo e suas fontes de suprimento sanguíneo em coelho da raça Nova Zelândia (Oryctolagus cuniculus)

The brains of 30 New Zealand rabbits (Oryctolagus cuniculus) were injected with red stained latex. The arteries of the ventral surface of the brain were systematized on the right (R) and on the left (L) side with the respective percentage of appearance: the aortic arch emitted the braquicephalic trunk and the left subclavian artery (83.3%); or the braquicephalic trunk, the left common carotid artery and the left subclavian artery (16.7%). The braquicephalic trunk emitted the right and the left common carotid arteries and the right subclavian artery (83.3%); or the right common carotid artery and the right subclavian artery (16.7%). The common carotid arteries were divided into external and internal carotid arteries (96.7% on the R, 100% on the L.). The internal carotid artery to the R was present (96.7%) and absent (3.3%), and to the L, was present (100%). The rostral choroidal artery to the R was collateral branch of the rostral branch of the internal carotid artery (83.3%), collateral branch of caudal branch of the internal carotid artery (16.7%), and to the L was collateral branch of the rostral branch of the internal carotid artery (93.3%), collateral branch of the caudal branch of the internal carotid artery (6.7%). The middle cerebral artery to the R and to the L was single (80%) and double (20%). The rostral cerebral artery to the R had middle caliber (90%), thin caliber (6.7%) and too thin caliber (3.3%), and to the L had middle caliber (76.7%), thin caliber (16.7%) and too thin caliber (6.7%). The internal ethmoidal artery was absent (73.3%), present and single (26.7%). The caudal cerebral artery to the R was single (66.7%), double (26.7%) and triple (6.7%), and to the L was single (63.3%) and double (36.7%). The terminal branches of the right and left vertebral arteries were present (100%, and formed the basilar artery (100%). The ventral spinal artery was present (100%). The caudal cerebellar artery, to the R was single (43.3%), single with labyrinthic artery isolated (26.7%) and double (30%), and to the L was single (50%), single with labyrinthic artery isolated (6.7%), double (40%) and triple (3.3%). The trigeminal artery to the R and to the L was present (100%). The rostral cerebellar artery to the R was single (53.3%) and double (46,7%), and to the L was single (63.3%) and double (36.7%). The rabbit's cerebral arterial circle was caudally closed (100%) and rostrally closed (93.3%) or opened (6.7%). The brain was supplied by the vertebral-basilar and carotid systems.

Foram utilizados 30 encéfalos de coelhos Nova Zelândia (Oryctolagus cuniculus), injetados com látex, corado em vermelho, com objetivo de sistematizar as artérias da base do encéfalo e suas fontes de suprimento sanguíneo. Sistematizou-se a origem das fontes de suprimento sanguíneo para o encéfalo e as artérias (Aa) da face ventral do mesmo, tanto à direita (D) como à esquerda (E), com suas respectivas percentagens de aparecimento: o arco aórtico emitiu tronco braquiocefálico e artéria (A.) subclávia E (83,3%), ou tronco braquiocefálico, A. carótida comum E e A. subclávia E (16,7%). O tronco braquiocefálico lançou A. carótida comum D e E e A. subclávia D (83,3%), ou A. carótida comum D e A. subclávia D (16,7%). A. carótida comum dividiu-se em Aa carótidas externa e interna (96,7% D, 100% E). A. carótida interna D presente (96,7%) e ausente (3,3%), à E presente (100%). A. corióidea rostral D ramo colateral do ramo rostral da A. carótida interna D (83,3%), ramo colateral do ramo caudal da A. carótida interna D (16,7%), à E, ramo colateral do ramo rostral da A. carótida interna E (93,3%), ramo colateral do ramo caudal da A. carótida interna E (6,7%). A. cerebral média D e E ímpar (80%) e dupla (20%). A. cerebral rostral D com calibre médio (90%), calibre fino (6,7%), calibre muito fino (3,3%), à E, com calibre médio (76,7%), calibre fino (16,7%), calibre muito fino (6,7%). A. etmoidal interna ausente (73,3%), presente e ímpar (26,7%). A. cerebral caudal D, ímpar (66,7%), dupla (26,7%) e tripla (6,7%), à E, ímpar (63,3%) e dupla (36,7%). Ramos terminais --das Aa. vertebrais D e E presentes (100%) formaram a A. basilar (100%). A. espinhal ventral ímpar presente (100%). A. cerebelar caudal D, ímpar (43,3%), ímpar com A. labiríntica isolada (26,7%) e dupla (30%), à E, ímpar (50%), ímpar com A. labiríntica isolada (6,7%), dupla (40%) e tripla (3,3%). A. trigeminal D e E presente (100%). A. cerebelar rostral D, ímpar (53,3%) e dupla (46,7%), à E, ímpar (63,3%) e dupla (36,7%). Observou-se que o círculo arterial Cerebral do coelho foi fechado caudalmente (100%), rostralmente fechado (93,3%) e aberto (6,7%). O encéfalo foi suprido pelos sistemas vértebro-basilar e carotídeo.

A systematic study of the brain base arteries in the turkey (Meleagris gallopavo) / Sistematização das artérias na base do encéfalo e suas fontes de suprimento sanguíneo em peru (Meleagris gallopavo)

Thirty heads with neck segments of turkeys (Meleagris gallopavo) were dissected for a systematic study of the arteries. The frequency of the arteries found was: Cerebral carotid artery, intercarotid anastomosis and internal ophthalmic artery (100 percent). Caudal branch of the cerebral carotid artery to the right (R) vestigial artery (70 percent) and developed (30 percent) and to the left (L) developed (70 percent) and vestigial artery (30 percent). Ventral tectal mesencephalic artery in (70 percent) to R and (30 percent) to L was the direct branch of the cerebral carotid artery to L (70 percent) and to R (30 percent) collateral branch of the developed caudal branch. Basilar artery to L in (70 percent) and to R (30 percent) formed from the developed caudal branch; rostral ventral cerebellar artery present (86.7 percent) and absent (13.3 percent) to R and L. Caudal ventral cerebellar artery to R single (73.3 percent), double (23.3 percent) and triple (3.3 percent); caudal ventral cerebellar artery to L single (73.3 percent) and double (26.7 percent). Dorsal spinal artery branch of caudal ventral cerebellar artery to R (80 percent) and to L (73.3 percent). The rostral branch of cerebral carotid artery showed as collateral branches the single caudal cerebral artery to R (100 percent) and to L (96.7 percent) while in (3.3 percent) it was double. The middle cerebral artery was single to R and L (100 percent). Cerebroethmoidal artery to R and L (100 percent) with its collateral branch to single rostral cerebral artery (90 percent) to R and (86.7 percent) to L and double (10 percent) to R and (13.3 percent) to L. Ethmoidal artery to R and to L (100 percent) single. The cerebral arterial circle was rostrally and caudally opened, so that the cerebral blood supply was exclusively made by the carotid system.

Trinta cabeças de peru (Meleagris gallopavo), com segmento de pescoço, foram dissecados para o estudo sistemático das artérias. As maiores ocorrências das artérias foram: Artéria (A.) carótida do cérebro, anastomose intercarótica e A. oftálmica interna (100 por cento). Ramo caudal da carótida do cérebro à direita (D) vestigial (70 por cento) e desenvolvido (30 por cento) e à esquerda (E) desenvolvido (70 por cento) e vestigial (30 por cento). A A. tectal mesencefálica ventral em (70 por cento) à D e (30 por cento) à E foi ramo direto da A. carótida do cérebro à E (70 por cento) e à D (30 por cento) ramo colateral do ramo caudal desenvolvido. A A. basilar à E em (70 por cento) e à D (30 por cento) formou- se do ramo caudal desenvolvido. A. cerebelar ventral rostral presente (86,7 por cento) e ausente (13,3 por cento) à D e E. A. cerebelar ventral caudal à D única (73,3 por cento), dupla (23,3 por cento) e tripla (3,3 por cento). A. cerebelar ventral caudal à E única (73,3 por cento) e dupla (26,7 por cento). A. espinhal dorsal ramo da A. cerebelar ventral caudal à D (80 por cento) e à E (73,3 por cento). O ramo rostral da A. carótida do cérebro apresentou como ramos colaterais a A. cerebral caudal à D única (100 por cento) e à E (96,7 por cento) já em (3,3 por cento) era dupla; A. cerebral média única à D e E (100 por cento). A. cerebroetmoidal à D e E (100 por cento) com seu ramo colateral a A. cerebral rostral única (90 por cento) à D e (86,7 por cento) à E e dupla (10 por cento) à D e (13,3 por cento) à E. A. etmoidal à D e à E (100 por cento) única. Observou-se que o círculo arterial cerebral foi aberto rostralmente e caudalmente e o suprimento de sangue para o encéfalo foi exclusivamente pelo sistema carotídeo.

Systematization of the brain base arteries in ostrich (Struthio camelus)

Thirty ostrich (Struthio camelus) brains were used, injected with latex, to describe the arteries of the brain base.The largest occurrences of the arteries were: The cerebral carotid artery (100%), the intercarotid anastomosis(100%). The caudal branch of the cerebral carotid artery was, on the right (R), developed (53.3%) and vestigial(46.7%); on the left (L), developed (66.7%) and vestigial (33.3%). The ventral tectal mesencephalic artery onthe R (53.3%), on the L (66.7%), direct branch of the cerebral carotid artery on the R (43.3%), on the L (30%)and, direct branch of the basilar artery (3.3%) in both antimeres. The basilar artery was a single vessel (80%),double in (13.3%) and “in island” formation (6.7%). The caudal ventral cerebellar artery was single (96.7%),double (3.3%) on the R and, single (93.3%), double (6.7%) on the L. The dorsal spinal artery was a collateralbranch of the caudal ventral cerebellar artery on the R (96.7%), on the L (93.3%). The ventral spinal artery wasdouble (90%) and single (10%). The rostral branch of the cerebral carotid artery (100%). The caudal cerebralartery, on the R, was double (90%) and single (10%); on the L, was double (53.3%) and single (46.7%). Themiddle cerebral artery was a single vessel (100%). The cerebroethmoidal artery was single (100%). The rostralcerebral artery was single (90%), double (10%) on the R and single (96.7%), double (3.3%) on the L. Thecerebral arterial circle was rostrally open (100%) and, caudally, open (80%) and closed (20%).

Systematization, description and territory of the caudal cerebral artery of the brain in broad-snouted Caiman (Caiman latirostris) / Sistematização, descrição e território da artéria cerebral caudal no cérebro do jacaré do papo-amarelo (Caiman latirostris)

Thirty heads with the neck segment of Caiman latirostris were used. The animals were provided from a creation center called Mister Caiman, under the authorization of the Brazilian Institute of Environment and Renewable Natural Resources (Ibama). Animals were sacrificed according to the slaughtering routine of the abattoir, and the heads were sectioned at the level of the third cervical vertebra. The arterial system was washed with cold saline solution, with drainage through jugular veins. Subsequently, the system was filled with red colored latex injection. Pieces were than fixed in 20 percent formaldehyde, for seven days. The brains were removed, with a spinal cord segment, the duramater removed and the arteries dissected. At the level of the hypophysis, the internal carotid artery gave off a rostral branch, and a short caudal branch, continuing, naturally, as the caudal cerebral artery. This artery projected laterodorsalwards and, as it overpassed the optic tract, gave off its I (the first) central branch. Penetrated in the cerebral transverse fissure, emitting the diencephalic artery and next its II (second) central branch. Still inside the fissure, originated occipital hemispheric branches and a pineal branch. Emerged from the cerebral transverse fissure, over the occipital pole of the cerebral hemisphere. Projected rostralwards, sagital to the cerebral longitudinal fissure, as interhemispheric artery. This artery gave off medial and convex hemispheric branches to the respective surfaces of the cerebral hemispheres, anastomosed with its contralateral homologous, forming the common ethmoidal artery. This artery entered the fissure between the olfactory peduncles, emerging ventrally and dividing into ethmoidal arteries, right and left, which progressed towards the nasal cavities, vascularizing them. The territory of the caudal cerebral artery included the most caudal area of the base of the cerebral hemisphere, its convex surface, the olfactory peduncles and bulbs, the choroid plexuses and the diencephalus with its parietal organs.

Foram utilizadas trinta cabeças com o segmento de pescoço de Caiman latirostris. Os animais eram provenientes do Criatório Mister Caiman sob a autorização do Instituto Brasileiro de Meio Ambiente e dos Recursos Naturais Renováveis (Ibama). Os animais foram sacrificados de acordo com as normas de rotina de abate do frigorífico e as cabeças foram seccionadas na altura da terceira vértebra cervical. O sistema arterial foi lavado com solução salina 0.9 por cento resfriada, com drenagem pelas veias jugulares. Em seguida, o sistema foi preenchido com injeção de látex, corado em vermelho As peças foram então fixadas em formaldeído a 20.0 por cento por sete dias. O cérebro foi removido, com um segmento de medula espinhal, a dura-máter retirada e as artérias dissecadas. Na altura da hipófise, a artéria carótida interna emitiu um ramo rostral e, um curto ramo caudal, continuando-se naturalmente, como artéria cerebral caudal. Esta se projetou látero-dorsalmente e ao sobrepassar o trato óptico, emitiu seu I (primeiro) ramo central. Penetrou na fissura transversa do cérebro, lançando a artéria diencefálica e a seguir seu II (segundo) ramo central. Ainda dentro da fissura originou ramos hemisféricos occipitais, e um ramo pineal. Emergiu da fissura transversa do cérebro, no pólo occipital do hemisfério cerebral. Projetou-se rostralmente, sagital a fissura longitudinal do cérebro, como artéria interhemisférica. Esta artéria lançou ramos hemisféricos convexos e mediais para as respectivas faces dos hemisférios cerebrais, anastomosou-se com sua homóloga contralateral, formando uma artéria etmoidal comum. Esta mergulhou na fissura entre os pedúnculos olfatórios emergindo ventralmente e, dividindo-se em artérias etmoidais, direita e esquerda, as quais progrediram para as cavidades nasais, vascularizando-as. O território da artéria cerebral caudal compreendeu a área mais caudal da base do hemisfério cerebral, sua face convexa, os pendúculos e bulbos olfatórios, plexo corióides e o diencéfalo com seus órgãos parietais.

A systematic study of the brain base arteries inbroad-snouted caiman (Caiman latirostris)

The objective of this study was to describe and systematize the encephalic arterial vascularization of this reptile,by providing a standard irrigation model with its major variations. Thirty broad-snouted caiman heads andtwo whole specimens were used. The arterial system was filled with red-colored latex. Only a single source ofblood supply was observed in caimans and it originated from the left aortic arch. This vessel is called the azygoscarotid artery. At the caudal base of the skull, ventral to the first cervical vertebrae, it divided into two internalcarotid arteries. The internal carotid arteries divided into a rostral branch and a short caudal branch at thehypophysis level, which continued naturally as the caudal cerebral artery. The short caudal branch gave off itsmedium-caliber portion which, gave off the mesencephalic and the ventral rostral cerebellar arteries. Then thiscaudal branch anastomosed with its contralateral counterpart, forming the basilar artery. This artery followedthe ventral median fissure of the medulla oblongata, giving off the ventral caudal cerebellar and dorsal spinalarteries, and abandoning the cranial cavity through the foramen magnum as the ventral spinal artery. Therostral branch gave off the middle cerebral, rostral cerebral and rostral communicating arteries. The middlecerebral artery arose from a network originated from one to five collateral branches of the rostral branch of theinternal carotid artery. It was observed that the cerebral arterial circle was rostrally and caudally closed and,therefore, the cerebral blood supply was exclusively made by the carotid system.