Chlorpheniramine impairs functional recovery in Carassius auratus after telencephalic ablation

We determined the effect of an H1 receptor antagonist on the functional recovery of Carassius auratus submitted to telencephalic ablation. Five days after surgery the fish underwent a spatial-choice learning paradigm test. The fish, weighing 6-12 g, were divided into four groups: telencephalic ablation (A) or sham lesion (S) and saline (SAL) or chlorpheniramine (CPA, ip, 16 mg/kg). For eight consecutive days each animal was trained individually in sessions separated by 24 h (alternate days). Training trials (T1-T8) consisted of finding the food in one of the feeders, which were randomly blocked for each subject. Animals received an intraperitoneal injection of SAL or CPA 10 min after the training trials. The time spent by the animals in each group to find the food (latency) was analyzed separately at T1 and T8 by the Kruskal-Wallis test, followed by the Student Newman-Keuls test. At T1 the latencies (mean ± SEM) of the A-SAL (586.3 ± 13.6) and A-CPA (600 ± 0) groups were significantly longer than those of the S-SAL (226.14 ± 61.15) and S-CPA (356.33 ± 68.8) groups. At T8, the latencies of the A-CPA group (510.11 ± 62.2) remained higher than those of the other groups, all of which showed significantly shorter latencies (A-SAL = 301.91 ± 78.32; S-CPA = 191.58 ± 73.03; S-SAL = 90.28 ± 41) compared with T1. These results support evidence that training can lead to functional recovery of spatial-choice learning in telencephalonless fish and also that the antagonist of the H1 receptor impairs it.

Chlorpheniramine facilitates inhibitory avoidance in teleosts submitted to telencephalic ablation

The present study investigated the involvement of H(1) histaminegic receptor on the acquisition of inhibitory avoidance in Carassius auratus submitted to telencephalic ablation. The fish were submitted to telencephalic ablation 5 days before the experiment. The inhibitory avoidance procedure included 1 day for habituation, 3 days for training composed of 3 trials each (1st day: T1, T2, T3; 2nd day: 2T1, 2T2, 2T3; 3rd day: 3T1, 3T2, 3T3) and 1 day for test. On training days, the fish were placed in a white compartment, after 30 s the door was opened. When the fish crossed to a black compartment, a weight was dropped (aversive stimuli). Immediately after the third trial, on training days, the fish received, intraperitoneally, one of the pharmacological treatments (saline (N = 20), 8 (N = 12) or 16 (N = 13) µg/g chlorpheniramine, CPA). On the test day, the time to cross to the black compartment was determined. The latency of the saline group increased significantly only on the 3rd trial of the 2nd training day (mean ± SEM, T1 (50.40 ± 11.69), 2T3 (226.05 ± 25.01); ANOVA: P = 0.0249, Dunn test: P < 0.05). The group that received 8 µg/g CPA showed increased latencies from the 2nd training day until the test day (T1 (53.08 ± 17.17), 2T2 (197.75 ± 35.02), test (220.08 ± 30.98); ANOVA: P = 0.0022, Dunn test: P < 0.05)). These results indicate that CPA had a facilitating effect on memory. We suggest that the fish submitted to telencephalic ablation were able to learn due to the local circuits of the mesencephalon and/or diencephalon and that CPA interferes in these circuits, probably due an anxiolytic-like effect.

Chlorpheniramine impairs spatial choice learning in telencephalon-ablated fish

This work investigated the effect of the Hj receptor blockade in the forebrain of ablated Carassius auratus in a simple stimulus-response learning task using a T-maze test with positive reinforcement. The goldfish were submitted to surgery for removal of both telencephalic lobes five days before beginning the experiment. A T-shaped glass aquarium was employed, with two feeders located at the extremities of the long arm. One of the two feeders was blocked. The experimental triáis were performed in nine consecutive days. Each fish was individually placed in the short arm and confined there for thirty seconds, then it was allowed to swim through the aquarium to search for food for ten minutes (máximum period). Time to find food was analysed in seconds. Animáis were injected intraperitoneally with chlorpheniramine (CPA) at 16 mg/kg of body weight or saline after every trial, ten minutes after being placed back in the home aquarium. The results show that all the training latencies of the A-SAL group were higher than the latencies of the S-SAL group. The S-SAL group had decreased latencies from the second trial on, while the S-CPA group showed decreased latencies after the fourth trial. The A-SAL group showed reduced latencies after the fifth trial, but the A-CPA group mainteined the latencies throughout the experiment. This suggests that CPA impairs the consolidation of learning both on telencephalon ablated animáis and in sham-operated ones through its action on mesencephalic structures of the brain and/or on the cerebellum in teleost fish.

Revisão anatômica do seio venoso sagital dorsal no crânio de cães braquicéfalos / Anatomic features of the dorsal venous sinus in skull of brachycephalous dogs

Os seios venosos do crânio realizam a drenagem do cérebro e da medula espinhal, a fim de manter a homeostasia e o perfeito funcionamento do sistema nervoso central. Lesões na rede venosa cerebral podem causar déficits severos tais como hemiplegia, hemorragia, coma e morte. Os seios venosos são importantes pontos de referência para a realização de técnicas cirúrgicas de acesso ao cérebro. Este estudo visou analisar o trajeto do seio venoso sagital dorsal no crânio de cães braquicéfalos. Os animais braquicéfalos possuem crânios curtos e com características biométricas específicas. Foram utilizados 8 crânios de cães da raça Boxer, que foram submetidos à injeção de látex com pigmento corado e sulfato de bário. Após a perfusão, foram feitas radiografias contrastadas e imagens de tomografia computadorizada para relacionar o seio venoso com a estrutura óssea e dimensões relativas da calota craniana. Os crânios apresentaram índice cefálico (IC) médio de 91,24±8,34mm e índice crânio-facial (ICF) médio de 2,89±0,23mm. As mensurações do seio venoso sagital dorsal, relativas à calota craniana, apresentaram os seguintes valores médios: Area = 10,18±4,69mm²; D1 = 11,84±2,35mm; D2 = 19,57±2,61mm; D3 = 17,88±2,31mm; D4 = 25,32±5,68mm; e D5= 24,84±4,40mm.

The dorsal venous sinuses of the Dura mater perform the cerebral and spinal cord drainage to keep homeostasis of the Central Nervous System. Injuries in the cerebral venous network may cause severe deficits, including hemiplegia, hemorrhage, coma and death. The main landmark for neurologic surgery is the Dura mater venous sinus. The aim of this study is to analyse the pathway of the Sinus sagittalis dorsalis in the brachycephalous skull, as the brachycephalous dogs have specific characteristics. The skulls were taken from 8 Boxer dogs and venous perfusion with latex and barium sulfate solution was performed. After the perfusion, radiographies and tomographies were obtained to relate the dorsal sagittal sinus and the skull averages. The cephalic index showed mean values of 91.24±8.34cm, and the cranio-facial index was 2.89±0.23cm. The venous sinus mensuration interface to the skull was: Area = 10.18±4.69mm²; D1 = 11.84±2.35mm; D2 = 19.57±2.61mm; D3 = 17.88±2.31mm; D4 = 25.32±5.68mm e D5 = 24.84±4.40mm.

Consenso para el tratamiento de las metástasis cerebrales / Consensus about cerebral metastases treatment

El avance en la terapia oncológica ha hecho del tratamiento de las metástasis cerebrales un factor primordial en el tiempo de sobrevida y la calidad de vida de los pacientes con cáncer. A pesar de que existen numerosas publicaciones sobre el tema, no existe todavía un consenso sobre la mejor estrategia terapéutica, problablemente por la heterogeneidad de la población en términos de estado funcional, tipo de neoplasia, control sistémico de la enfermedad y número y localización de las lesiones en el sisteman nervioso central. Nuestro objetivo es presentar recomendaciones generales basadas en un análisis racional para guiar el manejo práctico de las metástasis cerebrales. Con este propósito, un equipo multidisciplinario integrado por neurocirujanos, neurooncólogos, neuropatólogos, radioterapeutas y neurólogos fue convocado para conducir una búsqueda minuciosa en las publicaciones en inglés y español a través de PubMed (1980-2006) coincidiendo con el comienzo del empleo de la resonancia magnética en la práctica médica. Se seleccionaron revisiones y artículos originales con un n=o>a 20. También se incluyeron capítulos de libros escritos por expertos conocidos. La evaluación de la literatura así como la experiencia de los autores permitió el desarrollo del "Consenso para el Tratamiento de las Metástasis Cerebrales". Finalmente los autores esperan que elpresente trabajo contribuya a un abordaje multidisciplinario para el manejo de las metástasis cerebrales con recomendaciones simples y prácticas y probablemente estimule nuevos desarrollos en este campo. Palabras clave: cirugía, metástasis cerebrales, quimioterapia, radioterapia

The advances in oncological therapies has made brain metastases treatment a major factor influencing the survival time and the quality of life patients with cancer. Although there are numerous publications on the issue, there is no consensus about the best treatment strategy. This is probably due to population heterogeneity in terms of functional status, type of neoplasia, control of the systemic disease, and the number and localization of the lesions in the cetral nervous system. Our objective is to present general recommendations based on a rational analysis in order to guide the practical management of brain metastases. With this purpose, a multidisciplinary team composed by neurosurgeons, neurooncologists, neuropathologist, radiotherapist and neurologists were brought together to conduct athrough search in english and spanish publications through PubMed (1980-2006). The starting period was set at the beginning of the use of magnetic resonance in medical practice. Reviews and original articles with n=or>20 were selected. Also, book chapters of renowned authors in the different consulted areas were included. The assessment of the literature, in addition to the experience of the authors allowed the development of "Consensus for the treatment of Brain Metastases". Finally, the authors expect that the present work will contribute to the multidisciplinary approach in the management of brain metastases with simple and practical recommendations, and probably stimulating future developments in this field. Key words: cerebral metastasis, chemotherapy, radiotherapy, surgery.

Ultrasonido intraoperatorio en neurocirugía: aspectos técnicos / Intraoperative ultrasound in neurosurgery: technical aspects

Introducción. La ultrasonografía intraoperatoria en neurocirugía es una técnica útil, especialmente en la cirugía oncológica. Nuestro propósito es presentar los aspectos prácticos de su aplicación y a la vez describir nuestra experiencia inicial con su uso. Material y Métodos. Se empleó el ultrasonido TITAN™ de la empresa Sonosite Inc. Bothell, WA. USA con diferentes modelos de transductores. El estudio se realizó durante cuatro etapas de la cirugía: al realizar la craneotomía/laminotomía sobre la duramadre, al abrir duramadre sobre tejido neural, al resecar la lesión y posteriormente al cerrar la duramadre. Resultado. La identificación óptima de la lesión y de las estructuras anatómicas adyacentes se logró utilizando el transductor L38/5-10 Mhz. La adecuada visualización de las lesiones fue posible en todos los casos que se utilizó este transductor. No se logró una visualización adecuada en 2 casos en los cuales se utilizo el transductor C15/2-4 Mhz. Conclusión. La ultrasonografía intraoperatoria es útil en localizar lesiones e identificar estructuras anatómicas adyacentes. El transductor óptimo es uno que posea una cabeza de transductor pequeña plana (2.5cm x 1.5cm o menos) que emita frecuencias que oscilen entre 4-10 Mhz.

Microanatomia cirúrgica relevante na amigdalohipocampectomia seletiva: um estudo estereoscópico / Relevant anatomy regarding the selective amygdalohipocampectomy-campectomy printing study

O lobo temporal é o mais heterogêneo do cérebro humano, tendo em sua composição alocórtex e estruturas do sistema límbico. Crises convulsivas parciais complexas com origem no lobo temporal correspondem a 70 dos pacientes refratários ao tratamento clínico que são encaminhados a centros de cirurgia de epilepsia. Os procedimentos cirúrgicos utilizados no tratamento da epilepsia do lobo temporal tiveram forte impacto na qualidade de vida dos pacientes. O conhecimento anatômico profundo é fundamental para ressecções cirúrgicas seguras das estruturas do lobo temporal. Ao serem estudados diferentes ângulos de visão, não somente a anatomia convencional, mas também a anatomia microcirúrgica e técnicas não-convencionais de dissecção, como a dissecção de fibras brancas cerebrais a segurança do procedimento é aumentada à medida que aumenta a chamada “visão de raios X” do cirurgião. O objetivo deste estudo é apresentar a anatomia relevante na amigdalohipocampectomiaseletiva com técnicas de dissecção convencionais e não-convencionais, bem como documentar com fotografias convencionais e estereoscopia. Métodos: Vinte cérebros fixados em formalina e seis cadáveres fixados em Carolina’s perfect solution® (Carolina Biological Supply company, Burlington, NC) foram dissecados com microscópio cirúrgico com aumentos de três a 40 vezes. Cada crânio foi colocado no fixador tipo Mayfield e a cabeça estendida e rodada para simular a posição cirúrgica. Craniotomia pterional e amigdalohipocampectomia seletiva transilviana foram realizadas a seguir. As dissecções anatômicas foram documentadas com estereoscopia. Resultados: A amigdalohipocampectomia seletiva transilviana é documentadapor etapas e a dissecção de fibras brancas utilizada para ilustrar esta anatomia. Conclusão: A complexa anatomia do lobo temporal relacionada à amigdalohipocampectomia seletiva e suas variantes podem ser totalmente entendidas mediante diferentes perspectivas anatômicas.