Distribution of primary afferent fibers projecting from hindlimb cutaneous nerves to the medulla oblongata in the cat and rat

Ueyama, Teizo; Houtani, Takeshi; Ikeda, Michiko; Sato, Kazuo; Sugimoto, Tetsuo; Mizuno, Noboru

doi:10.1002/cne.903410202

Cited by 20 publications

(20 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Bilateral labeling was limited to the level of obex and just caudal to it. Results of the tracing study confirmed the bilaterality of these pathways suggested by the electrophysiological recordings, a finding consistent with two previous tracing studies (55,56), in which labeling also was seen to move bilaterally near the level of obex and no Gr labeling occurred by injecting just the motor branch of the perineal nerve (57).…”

Section: Penile Inputs To Nucleus Gracilissupporting

confidence: 90%

Identification of penile inputs to the rat gracile nucleus

Cothron

Massey²,

Onifer³

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

Cothron KJ, Massey JM, Onifer SM, Hubscher CH. Identification of penile inputs to the rat gracile nucleus. Am J Physiol Regul Integr Comp Physiol 294: R1015-R1023, 2008. First published January 2, 2008 doi:10.1152/ajpregu.00656.2007.-Neurons in the medullary reticular formation (MRF) of the rat receive a vast array of urogenital inputs. Using select acute and chronic spinal cord lesions to identify the location of the ascending neural circuitries providing either direct or indirect inputs to MRF from the penis, our previous studies demonstrated that the dorsal columns and dorsal half of the lateral funiculus convey low-and high-threshold inputs, respectively. In the present study, the gracile nucleus was targeted as one of the likely sources of low-threshold information from the penis to MRF. Both electrophysiological recordings and neuroanatomical tracing [injection of cholera toxin B subunit (CTB) into a dorsal nerve of the penis] were used. After discrimination of a single neuron responding to penile stimulation, testing for somatovisceral convergence was done (mechanical stimulation of the distal colon and the skin over the entire hindquarters). In 12 rats, a limited number of neurons (43 in total) responded to penile stimulation. Many of these neurons also responded to scrotal stimulation (53.5%, dorsal and/or ventral scrotum) and/or prepuce stimulation (46.5%). Histological reconstruction of the electrode tracks showed that the majority of neurons responding to penile stimulation were located ventrally within the medial onethird of the gracile nucleus surrounding obex. This location corresponded to sparse innervation by CTB-immunoreactive primary afferent terminals. These results indicate that neurons in the gracile nucleus are likely part of the pathway that provides low-threshold penile inputs to MRF, a region known to play an important role in mating processes. dorsal columns; pudendal; pelvic; convergence; cholera toxin b subunit SPINAL CORD INJURY RESULTS not only in significant sensory and motor dysfunctions of the hind limbs but in disruption of pathways responsible for normal sexual function. To devise effective treatments and therapies for these patients, a more thorough understanding of the spinal circuitries mediating sexual function is needed. In the normal spinal cord, the dorsal columns are organized with sensory information from the lower half of the body traveling more medially as it ascends in the fasciculus gracilis and from the upper body further laterally in the fasciculus cuneatus (35, 60). These somatotopically organized projections terminate into the dorsal column nuclei of the caudal medulla, which comprises the nucleus gracilis (Gr) (input from the lower body) and both the nucleus cuneatus (Cu) and external cuneate nucleus (input from the upper body). In the rat Gr, more caudal structures, such as the tail and perineum are represented medially vs. structures such as the leg and foot, which are found to be located more laterally in the nucleus (36). Maslany et al. (31) demonstrate...

show abstract

Section: Penile Inputs To Nucleus Gracilissupporting

confidence: 90%

Identification of penile inputs to the rat gracile nucleus

Cothron

Massey²,

Onifer³

et al. 2008

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

show abstract

“…Separate patches and clusters of neurons along the rostrocaudal axis of the nucleus receive inputs from the same skin regions. This is not only the case for the primates of the present study, but for other mammals as well (Maslany et al, 1991;Wessels et al, 1991;Ueyama et al, 1994). At a more detailed level of analysis, single afferents likely branch to innervate several cell clusters along the rostrocaudal axis of the gracile nucleus (for the cuneate nucleus, see Fyffe et al, 1986;Weinberg et al, 1990).…”

Section: Functional Implications Of the Anatomical Organization Of Thmentioning

confidence: 72%

“…Based on microelectrode recordings, Johnson et al (1968) described a mediolateral progression of representations in the gracile nucleus from tail to foot to leg, as in the present study. In the gracile nucleus of cats, Ueyama et al (1994) found that the dense foci of the terminal labeling from nerves innervating the distal parts of the hindlimb were located more dorsomedial than those of the nerves innervating the proximal parts, and label from the foot occupied a more extensive termination zone in the gracile nucleus than label from the proximal hindlimb. These results are in good agreement with our data from all four primate species studied.…”

Section: Gracile Nuclei Of Other Mammalsmentioning

confidence: 97%

“…Of the three main divisions of the medullary complex, most is known about the termination patterns of afferents in the trigeminal and cuneate divisions. Most of these studies have been on cats (Kruger et al, 1961;Millar and Basbaum, 1975;Nyberg, 1988), and rats (Nord, 1967;Maslany et al, 1990Maslany et al, , 1991Maslany et al, , 1992Crockett et al, 1993a,b;Ueyama et al, 1994;Florence and Lakshman, 1995), with some important studies on raccoons (Johnson et al, 1968;Rasmusson, 1989). In primates, most studies have been on New or Old World monkeys, and most of these have focused on how afferents from the forelimb terminate in the cuneate nucleus (Hummelsheim et al, 1985;Culberson and Brushart, 1989;Florence et al, 1988Florence et al, , 1989Florence et al, , 1991Wall 1996, 1999a,b).…”

mentioning

confidence: 96%

See 1 more Smart Citation

Organization of primary afferent projections to the gracile nucleus of the dorsal column system of primates

Kaas

2006

J of Comparative Neurology

View full text Add to dashboard Cite

In order to reveal the somatotopic organization of the gracile nucleus of the dorsal column-trigeminal complex, neuroanatomical tracers were injected subcutaneously into various parts of the hindlimb and tail of prosimian galagos, New World monkeys, and Old World monkeys. In most cases, tracers were injected bilaterally, and into more than one body part. In six cases, two different, distinguishable tracers were injected into the same hindlimb. Brainstem and spinal cord sections were processed for tracers transported by cutaneous afferents to terminations in the gracile nuclei. Foci of terminations were related to the cell-cluster architecture of the gracile nuclei in sections processed for cytochrome oxidase or stained for cell bodies (Nissl stain). In all taxa, terminations labeled by the injections were distributed in a patchy fashion along the rostrocaudal length of the ipsilateral gracile nucleus. Terminations were largely but not completely focused within the cytochrome oxidase dense cell clusters. Across taxa, afferents from the tail, foot, lower leg, and upper leg terminated in a mediolateral sequence within the gracile nucleus. Afferents from the glabrous skin of toes 1-5 terminated in a ventromedial to dorsolateral sequence in owl, squirrel, and macaque monkeys, but an altered arrangement was seen in the galagos, with a ventrolateral location for toe 1. The use of two tracers in squirrel monkeys indicated that terminations from adjacent toes formed adjacent and largely segregated patches. Terminations of afferents from the plantar pad (sole) of the foot tended to surround those from the glabrous toes.

show abstract

“…Comparing with the neurons of the cell nest region, the receptive fields of the hair stimulation in the reticular region are larger, the dorsal column input to this region is lesser and not arranged somatotopically, the neurons of this region have large cortical input and a small proportion of its neurons contribute to the medial lemniscus fibers [30]. The physiological studies of the Gr in the cat showed also that the terminal ends of the nerve fibers which carry the sensation from the distal parts of the hindlimb ‖the foot‖ have more extensive representation at the Gr and are a located dorsomedial to those of the nerve fibers which carry the sensation from the proximal parts of the hinlimb [21,55]. …”

Section: Catsmentioning

confidence: 99%

Functional and Anatomical Features of the Dorsal Column Nuclei in Mammals and Lower Animals

Zaqout

Al-Hussain²

2013

AJMBR

View full text Add to dashboard Cite

The dorsal fasciculi of the spinal cord are known as the chief pathways for the conduction of impulses underlying deep sensibility and tactile discrimination from limbs which reach the thalamus and ultimately the cerebral cortex after a relay at a bulbar level, the dorsal column nuclei. It is believed that the development of the dorsal fasciculi and their nuclei in the mammalian and primate series is correlated with increasing sensory discrimination in the skin and the increased development of proprioceptive sense in the limb musculature. In this review we will discuss the reflection of the development of limbs and sensory discrimination in lower animals and mammals on the organization and some functional aspects of these nuclei.

show abstract

Distribution of primary afferent fibers projecting from hindlimb cutaneous nerves to the medulla oblongata in the cat and rat

Cited by 20 publications

References 63 publications

Identification of penile inputs to the rat gracile nucleus

Identification of penile inputs to the rat gracile nucleus

Organization of primary afferent projections to the gracile nucleus of the dorsal column system of primates

Functional and Anatomical Features of the Dorsal Column Nuclei in Mammals and Lower Animals

Contact Info

Product

Resources

About