Longitudinal extent of dorsal root fibres in the spinal cord and brain stem of the frog

Antal, Miklós; Tornai, István; Székely, George

doi:10.1016/0306-4522(80)90203-1

Cited by 50 publications

(35 citation statements)

References 16 publications

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“…A similar condition exists in frogs, where large-diameter myelinated primary afferent axons are distributed me dially to enter the dorsal columns and pro ject to widespread supraspinal regions [Antal et al, 1980], Primary afferent axons occupy discrete terminal zones in the spi nal cord of frogs depending on the origin and the modality of those axons [Szekely et al, 1982;Jhaveri and Frank, 1983]. Ven tral and lateral to the entry of the dorsal root, small-diameter axons segregate to form the dorsolateral fasciculus or Lissauer's tract (LT), first distinguished in the human spinal cord [Lissauer, 1885; trans lated by Earle, 1952], and recognized in a wide variety of vertebrates [Keenan, 1929] including anurans [Cajal, 1909-191 1; Ariens Kappers et al, 1936;Nikundiwe et ah, 1982], A nociceptive function has been impli cated for the small-diameter axons which enter LT from the dorsal root.…”

Section: Introductionmentioning

confidence: 99%

“…Since roots were transected 1-2 mm distal to the cord, the total distance of HRP diffusion in these axons was about 5-6 mm during a survival period of 20 h. This agrees with the HRP diffusion rate cited above [Bishop and King, 1982] and suggests that the extent of labelled axons was limited by the rate of HRP diffusion and did not represent the entire distribu tion of the axons. Further, we did not ob serve axons rostral to the level of the obex, in the cerebellum [e.g., Antal et al, 1980].…”

Section: Regional Variation In Lissauer's Tractmentioning

confidence: 99%

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Distribution and Ultrastructure of Primary Afferent Axons in Lissauer's Tract in the Northern Leopard Frog <i>(Rana pipiens)</i>

Rosenthal¹,

Cruce²

1985

Brain Behav Evol

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Dorsal roots were transected and filled with horseradish peroxidase to identify the primary afferent axons in Lissauer's tract (LT) of the spinal cord in a ranid frog with light and electron microscopy. Axons in LT could be traced at least 2–3 segments rostral and caudal to the level of the filled root. Some axons in LT entered a nucleus in the dorsal lateral funiculus at brachial and lumbar levels, while other axons terminated in widespread regions of the dorsal horn. Electron microscopy revealed unlabeled terminals with numerous large, dense-cored vesicles in LT. However, large vesicles were rarely observed and were never abundant in labelled primary afferent axons. S type synaptic contacts between labelled axons and unlabelled profiles were observed. The presynaptic axons in these synapses contained many small, spherical vesicles. The cross-sectional area of LT was related to the spinal cord level, with the largest area at the brachial level, an intermediate area at the lumbar level, and the smallest area at the thoracic level. No difference in number of labelled axons was observed in the medial and lateral parts of LT.

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Section: Introductionmentioning

confidence: 99%

Section: Regional Variation In Lissauer's Tractmentioning

confidence: 99%

Distribution and Ultrastructure of Primary Afferent Axons in Lissauer's Tract in the Northern Leopard Frog <i>(Rana pipiens)</i>

Rosenthal¹,

Cruce²

1985

Brain Behav Evol

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“…5 summarizes the present and previous data concerning the direct and indirect sensory input to the brainstem networks of preycatching behavior in the frog (Anderson, 2001;Antal et al, 1980;Corbacho et al, 2005;Deak et al, 2009;Harwood and Anderson, 2000;Kecskes et al, 2013Kecskes et al, , 2015Mandal and Anderson, 2010;Matesz, 1994;Matesz et al, 2008Matesz et al, , 2014Nishikawa, 2000). We can hypothesize that direct contacts of the trigeminal fibers with the trigeminal and facial motoneurons can be the morphological background of the synchronization and timing of the jaw closing and opening during the feeding movements.…”

Section: Resultsmentioning

confidence: 85%

Possible neural network mediating jaw opening during prey-catching behavior of the frog

Kovalecz

Kecskes

Birinyi

et al. 2015

Brain Research Bulletin

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Please cite this article in press as: Kovalecz, G., et al., Termination of trigeminal afferent fibers on facial motoneurons: Possible neural network mediating jaw opening during prey-catching behavior of the frog. Brain Res. Bull. (2015) a b s t r a c tThe prey-catching behavior of the frog is a complex, well-timed sequence of stimulus response chain of movements. After visual analysis of the prey, a size dependent program is selected in the motor pattern generator of the brainstem. Besides this predetermined feeding program, various direct and indirect sensory inputs provide flexible adjustment for the optimal contraction of the executive muscles. The aim of the present study was to investigate whether trigeminal primary afferents establish direct contacts with the jaw opening motoneurons innervated by the facial nerve. The experiments were carried out on Rana esculenta (Pelophylax esculentus), where the trigeminal and facial nerves were labeled simultaneously with different fluorescent dyes. Using a confocal laser scanning microscope, close appositions were detected between trigeminal afferent fibers and somatodendritic components of the facial motoneurons.Quantitative analysis revealed that the majority of close contacts were encountered on the dendrites of facial motoneurons and approximately 10% of them were located on the perikarya. We suggest that the identified contacts between the trigeminal afferents and facial motoneurons presented here may be one of the morphological substrate in the feedback and feedforward modulation of the rapidly changing activity of the jaw opening muscle during the prey-catching behavior.

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“…Our previous results showed a significant overlap between the dendritic fields of XII motoneurons and termination areas of the V and XII afferent fibers raising the possibility of direct contacts between the XII motoneurons and V axon terminals Székely, 1977, 1978;Birinyi et al, 2004]. Additional sensory modulation of the activity of XII motoneurons is expected from the overlapping areas between the XII dendrites and sensory fibers of the glossopharyngeal-vagus nerve and the dorsal root fibers of the second cervical nerve Székely, 1977, 1978;Antal et al, 1980;Birinyi et al, 2004]. As the morphological background of these interactions, simultaneous labeling of XII motoneurons and sensory fibers with different fluorescent tracers revealed close appositions between the sensory terminals and the XII dendrites in the dorsomedial ( fig.…”

Section: Influence Of Sensory Modalities On the Activity Of The XII Mmentioning

confidence: 99%

Brainstem Circuits Underlying the Prey-Catching Behavior of the Frog

Matesz¹,

Kecskes²,

Bácskai³

et al. 2014

Brain Behav Evol

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Prey-catching behavior (PCB) of the frog consists of a sequence of movements as a stimulus-response chain of the behavioral pattern in which each action presents a signal for the subsequent event. The transformation of visual information into appropriate spatiotemporal patterns of motor activity is carried out by the motor pattern generators located in the brainstem reticular formation. The motor pattern generators provide input to the motoneurons either directly or via the last-order premotor interneurons (LOPI). Although the feeding program is predetermined in this way, various sensory mechanisms control the motor activity. By using neuronal labeling methods, we have studied the morphological details of sensorimotor integration related to the hypoglossal motoneurons to provide further insight into the neuronal circuits underlying the PCB in ranid frogs. Our major findings are as follows. (1) Dendrodendritic and dendrosomatic contacts established by the crossing dendrites of hypoglossal (XII) motoneurons may serve as a morphological option for co-activation, synchronization and proper timing of the bilateral activity of tongue muscles. The crossing dendrites may also provide a feedforward amplification of various signals to the XII motoneurons. The overlapping dendritic territories of the motoneurons innervating protractor and retractor muscles may facilitate the coordinated activities of the agonistic and antagonistic muscles. (2) The musculotopic organization of the XII motoneurons is reflected in the distribution of LOPI for the protractor and retractor muscles of the tongue. (3) Direct sensory inputs from the trigeminal, vestibular, glossopharyngeal-vagal, hypoglossal and spinal afferent fibers to the XII motoneurons may modulate the basic motor pattern and contribute to the plasticity of neuronal circuits. (4) The electrical couplings observed in the vestibulocerebellar neuronal circuits may synchronize and amplify the afferent signals. The combination of chemical and electrical impulse transmission provides a mechanism by which motoneurons can be activated sequentially.

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Longitudinal extent of dorsal root fibres in the spinal cord and brain stem of the frog

Cited by 50 publications

References 16 publications

Distribution and Ultrastructure of Primary Afferent Axons in Lissauer's Tract in the Northern Leopard Frog <i>(Rana pipiens)</i>

Distribution and Ultrastructure of Primary Afferent Axons in Lissauer's Tract in the Northern Leopard Frog <i>(Rana pipiens)</i>

Possible neural network mediating jaw opening during prey-catching behavior of the frog

Brainstem Circuits Underlying the Prey-Catching Behavior of the Frog

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