The lateral cervical nucleus of cat, dog and man

Abstract

This nucleus was identified in four cats, four dogs and nine human spinal cords, but was not identifiable in seven other human specimens. In all three species the nucleus extends rostrally into the lower third of the medulla. Cell measurements of the perikarya yielded a mean diameter of 34.1 p in the dog, 26.7 / . L in the cat, and 15.7 it in man, Nuclear diameters as well as the nucleus-cytoplasm and volume ratios were determined. The lateral cervical nucleus is considered to be rudimentary in man and was a well-defined structure in only 2 of 16 specimens. In one of these two cases a total of 5173 cells were counted in the nuclei of both sides at the C 1 arid medullary levels. Thc pertinence of these observations to the preservation of tactile sensation after injury of the dorsal columns in man, is discussed.The presence and location of a lateral cervical nucleus (LCN) in the cat has been established in a number of anatomical studies (Rexed and Brodal. '51: Rexed and Stram, '52: Brodal and Rexed, '53; Morin, '55; Morin and Catalano, '55; Rexed, '54; '64; Ha and Liu, '66; Westman, '68a,b; Grant and Westman, '69). This small group of neurons also has been identified in the dog (Kitai, Ha and Morin, '65). A lateral cervical nucleus was described in the monkey by Gardner and Morin ('57), Ha and Morin ('64), and Mizuno et al. ('67).Rexed ('58) stated that this nucleus was present in the dog, sheep, seal and whale but non-existent in the cervical cord of the rat, guinea pig, rabbit and possibly man. Gardner and Morin ('57) examined four human cervical cords and observed no lateral cervical nucleus. Similar negative findings were reported by Rexed ('58) and Seki ('62, '65 MATERIALS AND METHODSThe location of the neurons that cornprise the LCN of the cat and dog are well established. Transverse and longitudinal sections of these two species ( 4 cats and 4 dogs) were used for purposes of comparison and normal controls. Paraffin or frozcn sections of the cervical cord ( C l -3 ) and the lower half of the medulla were stained by either the cresyl violet, Lux01 blue-cresyl violet, Holmes silver-Luxol blue, or thionin technics.The human material used in the present study consisted of cervical cord and medulla segments from one newborn and 15 adults (38 to 76 years of age). Paraffin or frozen sections cut in two planes were stained by one or more of the methods noted above. Two each of the cat, dog and human specimens were sectioned and 9394 TBUEX, TAYLOR, SMYTHE AND GILDENBERG stained serially. The latter material was used to provide cell measurements of 100 neurons in each of the six specimens. All micrometer measurements ( fig. 1 ) were made with an oil immersion lens at a magnification of X 970, using the method described previously by Truex, Scott, Long and Smythe ('55). RESULTSA well developed lateral cervical nucleus (LCN) was present in all eight specimens of the cat and dog cervical spinal cord ( fig. 3 ) . A well defined LCN was observed in two human adult specimens. but the nucleus was poorly develo...

Recent advances in our understanding of the organization of dorsal horn neuron populations and their contribution to cutaneous mechanical allodynia

“…These cells usually have elongated dendrites that form a cylinder in the dorso-ventral axis. However, it is unclear whether the SCT exists in humans, as this tract might be rudimentary in primates (Truex et al 1970).…”

Anatomical organization of the lateral cervical nucleus in Artiodactyls

“…In addition, the size of LCN neurons was larger in calves than it was in pigs. Since previous studies have demonstrated that the neuronal size of the LCN neurons is not related to the animal body size (Truex et al 1970), we could assume that the bovine LCN is more developed than that of the pig. This is the opposite of the situation found in other nuclei in the bovine compared to the pig (Graïc et al 2018).…”

Experimental studies on the nucleus cervicalis lateralis (NCL) of <i>Macaca cyclopis</i> (Swinhoe) II. The spinal afferents to the nucleus cervicalis lateralis in the monkey

“…J ou and Tsai, 1971 ] of the spino-cervico-thalamic system of the Formosan rock-monkey (Macaca cyclopis) has demonstrated a thin, slender nucleus in the dorsolateral white column extending from I he low er portion of the medulla oblongata to the caudal half of the second cervical segment of the spinal cord. This nucleus occupies the same region and has a similar histological appearance to that of the NCL in the cat [Rexed and Brodal, 1951;Rexed and Strom, 1952;Truex et al, 1970): the dog [Kitai, Ha and Morin, 1963; Tin ex …”