Analysis of the brainstem internal morphology of the capuchin monkey (Cebus apella) / Análise da morfologia interna do tronco encefálico de macaco-prego (Cebus apella)

The gross anatomy and the internal morphology of the brainstem of the monkey Cebus apella were described based on the observations made on adult brainstens. Six adult Cebus apella monkeys were used for anatomical observations and for the study of the internal morphology they were cut into serial sections at six different levels (pyramidal decussation; superior portion of the olive; inferior portion of the olive; pons; superior colliculus and inferior colliculus) and properly stained for studies of the internal structure. Our results show that the Cebus apella brainstem is characterized by the presence of a bulbpontine sulcus; an enlarged brainstem, particularly of the medulla oblongata, with a consequent laterization of the trapezoid body, the presence of inferior olivary complex, the apparent origin of cranial nerves distant from the pyramids and of its decussation; presence of the antero-lateral sulcus separating the pyramids of the olives; expressive development of the trapezoid body, of the pons, nuclei of the pons and of the cerebral peduncle. These results are consistent with previous descriptions for other primates and suggest that the organization and development of the Brainstem structures share similarities with superior primates including humans which reflect the motor abilities of the studied species.

A anatomia e a morfologia interna do tronco encefálico (TE) do macaco-prego (Cebus apella) foram descritas com base nas observações feitas em troncos encefálicos de macacos adultos. Seis macacos Cebus apella adultos foram utilizados para as observações anatômicas. Para os estudos da morfologia interna os TE foram cortados seriadamente em seis níveis diferentes: decussação piramidal, porção superior da oliva, porção inferior da oliva, ponte, colículo superior e colículo inferior. Após esse procedimento eles foram corados com a técnica de Mulligan modificada por nós. Nossos resultados mostram que o TE de Cebus apella é caracterizado pela presença do sulco bulbo-pontino, aumento do tamanho do TE, especialmente da medula oblonga, com consequente lateralização do corpo trapezoide, presença do sulco ântero-lateral separando as pirâmides das olivas; desenvolvimento expressivo do corpo trapezoide, da ponte, dos núcleos da ponte e do pedúnculo cerebral. Estes resultados são consistentes com descrições prévias para outros primatas na literatura e sugerem que a organização e desenvolvimento do TE exibe semelhanças com primatas superiores, incluindo o homem, o que reflete as habilidades motoras da espécie estudada.

The innervation of the thymus gland in the rat: a HRP study

The marker horseradish peroxidase (HRP) was used to retrogradely label the cell bodies of origin of the nerve fibers responsible for thymic innervation. The thymus was exposed in albino rats under general anesthesia and a conjugate of HRP-WGA was injected bilaterally into the gland parenchyma. After a survival time of 3 days, the animals were anesthetized and perfused transcardially. Their brainstems were removed and serially sectioned and together with the whole sympathetic chains were processed for HRP demonstration. Labeled cell bodies were identified in the brainstem at the level of the retrofacial and ambiguous nuclei bilaterally. In the sympathetic chain, labeled neurons were present from the first cervical to the ninth thoracic ganglion, although they were detected in higher numbers in the superior cervical and stelate ganglia.

A quantitative study of the myenteric plexus of the distal end of the human esophagus

The density of ganlia and nerve cells in the myenteric plexus of the last distal (12 cem. of the human esophagus was determined in six esophagi from autops y material. The density of ganglia and nerve cells in cresyl violet stained stretch preparations of twelve esophageal segments, each 1 cm. in length, were compared. The highest values were recorded in segments 4,5 and 6 cm. above the cardiac incisura. The lowest densities of ganglia and nerve cells were found in segments 1,2 and 3 cm. above the cardiac incisura. The segments contained 659-3316 perikarya/cm2; ganglia contained 3-310 cells