Ultrastructure of motor nerve terminals in the anterior third of wistar rat tongue

Abstract

The nerve terminals of intrinsic muscular fibers of the tongue of adult wistar rats was studied by using silver impregnation techniques, transmission electron microscopy (TEM), and high resolution scanning electron microscopy (HRSEM) to observe the nerve fibers and their terminals. Silver impregnation was done according to Winkelman and Schmit, 1957. For TEM, small blocks were fixed in modified Karnovsky solution, postfixed in 1% buffered osmium tetroxide solution, and embedded in Spurr resin. For HRSEM, the parts were fixed in 2% osmium tetroxide solution with 1/15 M sodium phosphate buffer (pH 7.4) at 4 degrees C for 2 h, according to the technique described by Tanaka, 1989. Thick myelinated nerve bundles were histologically observed among the muscular fibers. The intrafusal nerve fiber presented a tortuous pathway with punctiform terminal axons in clusters contacting the surface of sarcolemma. Several myelinated nerve fibers involved by collagen fibers of the endoneurium were observed in HRSEM in three-dimensional aspects. The concentric lamellae of the myelin sheath and the axoplasm containing neurofilaments interspersed among the mitochondria were also noted. In TEM, myofibrils, mitochondria, rough endoplasmic reticulum, Golgi's apparatus, and glycogen granules were observed in sarcoplasm. It is also noted that the sarcomeres constituted by myofilaments with their A, I, and H bands and the electron dense Z lines. In areas adjacent to muscular fibers, there were myelinated and unmyelinated nerve fibers involved by endoneurium and perineurium. In the region of the neuromuscular junction, the contact with the sarcolemma of the muscular cell occurs forming several terminal buttons and showing numerous evaginations of the cell membrane. In the terminal button, mitochondria and numerous synaptic vesicles were observed.

Morphological characteristics of the papillae and lingual epithelium of guinea pig (Cavia porcellus)

“…Morphological descriptions of the tongue may range from the arrangement of the muscular and nervous fibres (Motoyama et al., ) to the disposal and types of saliva glands (Pícoli et al., 2011; Watanabe, Jin, & Nagata, ), the different shapes of the conjunctive tissue bundles and of the lingual papillae on the epithelial surface (Benetti, Pícoli, Guimarães, & Motoyama, ; Ciena et al., ).…”

Features of structure of nerve motor endings in the tongue of normal and dehydrated rats

“…Сравнивая данные научной литературы (Motoyama et al, 2009;Suzuki et al, 2012;Dana and McCaughey, 2015) и результаты собственного исследования, мы пришли к выводу, что, по сравнению с мышами, двигательные бляшки языка крысы имеют довольно большие размеры (соответственно 212,3 ± 4,8 и 540,1 ± 9,1 мкм 2 ), содержат большее количество ядер (соостветсвенно 4,9 ± 0,05 и 6,3 ± 0,07) и дифференцированные типы ветвления осевого цилиндра (рассыпной и магистральный).…”

“…Что касается двигательных окончаний языка человека, то многие исследователи предполагали, что двигательные окончания в языке человека в связи с участием его в акте членораздельной речи будут более дифференцированными, чем у других исследованных животных (Motoyama et al, 2009;Johnstone et al, 2010).…”

“…Строению периферического нервного аппарата скелетных мышц посвящено много работ (Bayline et al, 2001;Slaughter et al, 2006;Motoyama et al, 2009). В результате многочисленных исследований структура двигательных нервных окончаний и мионевральных синапсов в разных скелетных мышцах изучена достаточно хорошо (Mu and Sanders, 2010;Zciena et al, 2013).…”

Histochemical and ultrastructural changes of sternomastoid muscle in aged wistar rats

“…Animals of adult group (n = 5) and aged group (n = 5) were anesthetized intraperitoneally with urethane overdose (3 g/kg, ip), perfused with modified Karnovsky solution containing 2.5% glutaraldehyde and 2% paraformaldehyde in sodium phosphate buffer solution to 0.1 M (pH = 7.4) according to Motoyama et al (2009) methods. An incision was made in the anterolateral cervical spine for visualization and dissection of the SM (right and left) for fragments acquisition (3 mm 3 ).…”