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J L Dubbeldam

Publications and source records attributed to J L Dubbeldam.

At least 37 records · Page 2Linked to original sources
PubMed1994

Organization of the motor innervation of craniocervical muscles in the Mallard, Anas platyrhynchos L.

The organization of the motorsystem supplying the craniocervical muscles in the mallard was investigated. Firstly, the distribution of peripheral nerves supplying these muscles was macroscopically examined. Each muscle was found to be innervated by several spinal nerves, and each nerve to contact various muscles. Secondly, the position of neck motoneurons was studied by means of retrograde tracer transport. Labeled motoneurons were found in the supraspinal nucleus of the lower brainstem and in the ventral horn of the upper cervical cord. Each of the craniocervical muscles appeared to be innervated by a separate motorpool, and pools supplying different muscles were found to overlap considerably. Despite this overlap, some organization pattern could be recognized: the most ventral muscles are innervated by motoneurons that occupy dorsomedial positions, while more dorsal muscles are innervated by neurons at ventro-lateral positions. Thirdly, the arrangement of motoneurons innervating different parts of three craniocervical muscles was investigated by means of retrograde tracer transport. This indicated that each muscle part is also innervated by a separate motor column, and that columns supplying parts of the same muscle have similar positions in transverse sections but are shifted with respect to each other in the longitudinal direction. The separate columns of one muscle mingle to form one main motorpool. These results are discussed with respect to observations in other animals.

Animals↗
PubMed1992

Geometrical differences between neck motoneurons located in the brainstem and spinal cord in the mallard Anas platyrhynchos L.; a Golgi study.

The dendrite geometry of neck motoneurons located in the upper cervical cord and lower brainstem of the mallard was studied in Golgi silver impregnated material. Measurements were obtained from camera lucida drawings and concerned the extent and orientation of dendritic trees. Dendrites were found to be oriented predominantly parallel to the sagittal plane, and projections were asymmetric in the dorso-ventral direction. Comparison between motoneurons located in the supraspinal nucleus of the brainstem and motoneurons in the ventral horn of the upper spinal cord showed that dendrites of motoneurons in the first cell group branch more often than those of neurons in the latter group. In addition, dendritic trees of ventral horn motoneurons preferentially project into the field dorsal to the cell body.

Animals↗
PubMed1991

Functional morphological interpretation of the distribution of muscle spindles in the jaw muscles of the mallard (Anas platyrhynchos).

The morphology and distribution of muscle spindles of jaw and tongue muscles in the mallard were examined in serial transverse sections of single muscles and in horizontal sections of a whole head. Our observations on spindle morphology are in agreement with previous descriptions of spindles in birds. Some spindles differ in their innervation and the pattern of intrafusal muscle fibers. The spindles of individual adductor and pterygoid muscles are distributed unevenly. Some adductor muscles lack spindles, whereas those of other muscles are confined to limited areas. Jaw opening muscles and extrinsic tongue muscles lack spindles. The stretch of extrafusal muscle fibers could be estimated from the difference in sarcomere length for birds with the beak open and closed. Not all muscle fiber groups are stretched evenly over the whole range of jaw opening. Only those fiber groups that are continuously stretched during jaw opening contain spindles.

Animals↗
PubMed1990

The identification of the motor nuclei innervating the tongue muscles in the mallard (Anas platyrhynchos); an HRP study.

Horseradish peroxidase (HRP) histochemistry was used to identify the motoneurons innervating the tongue muscles in the mallard. Four nuclei are involved: the intermediate motor nucleus of N.VII innervating the stylohyoid, serpihyoid and ceratohyoid muscles, the retrofacial nucleus of N.IX innervating the m. geniohyoideus and the n. intermedius or motor nucleus of N.XII that innervates the mm. ceratoglossus and hyoglossus anterior and obliquus. The m. intermandibularis is innervated by a trigeminal motor subnucleus. There is no clear intranuclear organization. The results are summarized in Table I and discussed in connection with the role of each of the muscles during movements of the tongue.

Animals↗
PubMed1989

Shape and structure of the avian brain an old problem revisited.

Previously two approaches have been used to study the relation of shape and structure of the avian brain. One possibility is to consider shape, size and position of the brain as elements of the architecture of the head. The other approach was to consider the shape of the brain as expression of its structure. The significance of the two approaches for the explanation of the shape of the avian telencephalon is discussed in the light of recent data of brain organization. The two approaches are complementary in the explanation of position, size and shape of the brain.

Animals↗
PubMed1987

The organization of the nucleus basalis-neostriatum complex of the mallard (Anas platyrhynchos L.) and its connections with the archistriatum and the paleostriatum complex.

The pattern of connections between the nucleus basalis, neostriatum, hyperstriatum ventrale, paleostriatum complex and archistriatum in the mallard has been analysed using Nissl material and a combination of neuroanatomical tracing procedures (autoradiography, horseradish peroxidase and horseradish peroxidase-wheat germ agglutinin histochemistry, lesion/degeneration technique). The frontal part of the mallard's telencephalon is characterized by its multilayered organization and the predominantly vertical arrangement of the connecting fiber systems. The nucleus basalis, endstation of the ascending sensory trigeminal system, is a large laminar cell area with a dorsal and a ventral layer. The overlying neostriatum frontale can be subdivided into a medial, a dorsal and a ventral intermediate, and a lateral area. The nucleus basalis has distinct connections with the ventral layer and sparse connections with the dorsal layer of the intermediate neostriatum, and abundant reciprocal connections with the ventral layer of the hyperstriatum ventrale. The ventral intermediate neostriatum also has reciprocal connections with the hyperstriatum ventrale; its projections overlap partly with those from the nucleus basalis. The ventral layer of the intermediate neostriatum frontale has a distinct projection upon the paleostriatum augmentatum. The dorsal layer sends fibers to the lateral neostriatum, to the rostral "sensorimotor" part of the archistriatum and to the lateral zone of the lobus parolfactorius. Another source of archistriatal afferents is the paleostriatum ventrale, an area that may also send fibers to the brainstem. Figure 21 summarizes the connections described in this paper. The functional significance of this organization is discussed in relation to its possible role in the guidance of pecking and other feeding behaviors in the mallard. Differences in the organization of the systems in pigeon and mallard are related to the differing degrees of visual and tactile (trigeminal) contributions to feeding in the two birds. It is suggested that the pattern of reciprocal connections between the hyperstriatum ventrale and the nucleus basalis and ventral intermediate neostriatum frontale forms the neuroanatomical substrate for a "comparator-system".

Animals↗
PubMed1985

Primary sensory ganglion cells projecting to the principal trigeminal nucleus in the mallard, Anas platyrhynchos.

The trigeminal and glossopharyngeal ganglia of the adult mallard were studied following HRP injections into the principal trigeminal nucleus (PrV). The PrV consists of the principal trigeminal nucleus proper (prV) and the principal glossopharyngeal nucleus (prIX). After an injection into the prV, the labeled cells were found in the ipsilateral trigeminal ganglion. After an injection into the prIX, labeled cells were found in the ipsilateral distal glossopharyngeal ganglion, but not in the proximal ganglion of the IX and X cranial nerve (pGIX + X). In Nissl preparations, two types of ganglion cells in the trigeminal ganglion, pGIX + X, and distal ganglion of N IX could be distinguished: larger light cells and smaller dark cells. We could not determine whether the HRP-labeled cells belonged to both types or to one of them; but because all the labeled cells were over 20 microns, we concluded that the smallest cells (10-19 microns) in the trigeminal ganglion and distal ganglion of N IX did not project to the PrV. The labeling of the cells in the distal ganglion of N IX (average 34.5 microns) was uniformly moderate. In the trigeminal ganglion there were two types of labeled cells: heavily labeled cells (average 29.1 microns) and moderately labeled cells (average 35.1 l microns). These two types of labeling (moderate and heavy) may reflect two types of primary sensory neurons: cells with ascending, nonbifurcating axons, and cells with bifurcating axons. We speculate that the former are proprioceptive neurons and the latter tactile neurons. Labeled bifurcating axons in the sensory trigeminal complex gave off collaterals to all parts of the descending trigeminal nucleus except to the caudalmost laminated spinal part.

Animals↗
PubMed1985

An HRP study of the central connections of the facial nerve in the mallard (Anas platyrhynchos L.).

The location of several facialis innervated muscles has been determined by injecting individual muscles with horseradish peroxidase. The depressors of the lower jaw are represented in the dorsal facial motor nucleus and the tongue retractor muscles in the intermediate facial motor nucleus. HRP was also directly applied to the rostral and caudal branch of the facial nerve. The afferent connections are described including two small projections to the principal sensory nucleus and n. interpolaris which were not found in birds before.

Animals↗
PubMed1984

The subnuclei and primary afferents of the descending trigeminal system in the mallard (Anas platyrhynchos L.).

The descending trigeminal tract and its nuclei were described in the mallard (Anas platyrhynchos L.). The borders of the system were established in Fink-Heimer preparations after unilateral lesions placed in the Gasserian ganglion using the distribution of degenerated particles as a criterion. Adjacent sections, stained with the Nissl, Kluver-Barrera and Haggqvist methods were used in the description of cyto- and fibroarchitecture of the descending trigeminal system and surrounding structures. Descending fibers of the trigeminal root could be traced from the sensory root, ventral to the main sensory nucleus, into the descending tract and its nuclei. Its fibers pass into the spinal cord, but not farther than the third cervical segment. Seven subdivisions (parts a-g) were recognized, but could be combined into four subnuclei, viz. in the terminology of Olszewski: subnucleus oralis containing parts a and b; subnucleus interpolaris parts c and d; subnucleus caudalis part f; dorsal horn part g, etc. No primary trigeminal fibers could be traced to structures outside the main sensory nucleus and nuclei of the descending trigeminal tract; all projections were ipsilateral with the exception of a slight bilateral projection caudal to the obex. Partial lesions in the Gasserian ganglion showed a distribution of the mandibular, maxillary and ophthalmic fibers from dorsal to ventral respectively in the subnuclei oralis and interpolaris, and from medial to lateral in the subnuclei caudalis and dorsal horn. Afferents from the petrosal ganglion project upon the medial part of subnucleus interpolaris and upon a small cell group (nucleus of the ascending glossopharyngeal tract) that may be functionally part of the subnucleus oralis. The subnucleus caudalis receives afferents from the jugular ganglion. These differences in afferentation are used in a tentative functional interpretation of the subdivisions of the nucleus of the descending trigeminal system.

Animals↗
PubMed1984

The efferent connections of the nuclei of the descending trigeminal tract in the mallard (Anas platyrhynchos L.).

The efferent and intranuclear connections of the nuclei of the descending trigeminal tract of the mallard have been studied with lesion methods, and by axonal transport techniques following injections of tritiated leucine, and of horseradish peroxidase. The large subnucleus oralis neurons, including those belonging to the nucleus of the ascending glossopharyngeal tract, have proven to be the sole origin of trigeminocerebellar connections. The cerebellar afferents are of the mossy fiber type, and terminate predominantly in lobules V, VI and VII, and possibly, lobule IV. Trigeminocerebellar projections are ipsilateral except for the vermal area. Subnucleus interpolaris is the main source of intratrigeminal fibers that terminate in subnucleus oralis and the ventral part of the main sensory nucleus. These intranuclear connections are bilateral, but the medium-celled caudal part of subnucleus interpolaris in particular contains the majority of bi- and/or contralaterally projecting neurons. Additionally, the small cells in the rostral part of subnucleus interpolaris project ipsilaterally upon the parabrachial region, and upon the lateral reticular formation. Projections upon the parabrachial region furthermore emanate bilaterally from layer I of the rostral subnucleus caudalis. A minor part of layer I neurons sends its axons contralaterally along with those of the dorsal column nuclei toward the thalamic nucleus dorsolateralis posterior. Associated with the medial lemniscus, contralateral termination is also present in the lateral part of the ventral lamella of oliva caudalis, in the marginal zone of nucleus mesencephalicus lateralis, pars dorsalis and immediately surrounding intercollicular grey and, finally, in the nucleus intercalatus thalami. Furthermore, a bilaterally descending projection from subnucleus caudalis upon layers I and II of the rostral cervical cord was observed. Close to their origin subnucleus caudalis neurons project upon the adjoining caudal part of the lateral reticular formation.

Animals↗
PubMed1984

Brainstem mechanisms for feeding in birds: interaction or plasticity. A functional-anatomical consideration of the pathways.

Starting from a functional-anatomical analysis of the feeding apparatus of a bird, some expectations are formulated regarding the organization of the neuronal systems controlling the activity of this feeding apparatus. The organization of the premotor-motor system of the jaw muscles, of the exteroceptive system conveying tactile sense from tongue and beak to the brain and of the proprioceptive system of the jaw muscles is discussed. An attempt is made to relate specific structural features of these systems to their function in the control of the different feeding patterns of birds.

Afferent Pathways↗
PubMed1984

Afferent connections of nervus facialis and nervus glossopharyngeus in the pigeon (Columba livia) and their role in feeding behavior.

The afferent connections of the facial nerve and glossopharyngeal nerve in the pigeon have been studied with the Fink-Heimer I method after ganglion lesions. The nucleus ventrolateralis anterior of the solitary complex and an indistinct cell group S VII medial to the nucleus interpolaris of the descending trigeminal tract are the terminal fields for facial afferents. The n. ventrolateralis anterior also receives an important projection from the distal glossopharyngeal ganglion. Other projection areas of this ganglion are the n. presulcalis , n. centralis anterior, n. intermedius anterior and the parasolitary nucleus. Both ganglia have only ipsilateral projections. A lesion in the jugular ganglion complex causes degeneration throughout the ipsilateral solitary complex, in the contralateral n. commissuralis and n. centralis posterior and in the n. cuneatus externus. The lack of a substantial contribution to the trigeminal system is ascribed to the absence of mechanoreceptors in the tongue. The implications for the organization of neuronal pathways related to the feeding behavior are discussed.

Afferent Pathways↗
PubMed1983

Primary vagal nerve projections to the lateral descending trigeminal nucleus in boidae (Python molurus and Boa constrictor).

The primary vagal axons and terminals within the lateral descending trigeminal tract (dlv) and nucleus (DLV) of two species of Boidae are studied following HRP injections of the vagal nerve. Labeled fibers and terminals are found in the tail portion of the dlv and DLV, partly forming a neuropil at its margin. The labeled thin fibers and neuropil seem to correspond to the C-fibers and marginal neuropil of Crotalinae.

Afferent Pathways↗
PubMed1982

Exteroceptive and proprioceptive afferents of the trigeminal and facial motor nuclei in the mallard (Anas platyrhynchos L.).

Central pathways converging upon the trigeminofacial motor nuclei of the mallard were studied in order to elucidate neuroanatomically the presumed influence of primary sensory trigeminal afferents upon jaw muscle activity. The techniques used included the Fink-Heimer I method after lesions, and axonal transport labeling following injections of 3H-leucine or of HRP for retrograde identification of the neurons of origin. A general description is given of the trigeminofacial motor complex. Jaw closer muscles are innervated by trigeminal motor neurons, and facial motor neurons innervate the jaw depressor muscles. Two afferents premotor systems, one including the mesencephalic trigeminal nucleus (MesV) and the other the rhombencephalic reticular formation, are distinguished. The proprioceptive neurons of the mesencephalic trigeminal nucleus project upon the ipsilateral trigeminal motor nucleus and upon the nucleus supratrigeminalis. The latter cell group bilaterally projects upon the dorsal and intermediate parts of the facial motor nucleus and upon the dorsal and intermediate parts of the facial motor nucleus and upon part of the trigeminal motor nucleus. Exteroceptive information, relayed through the primary sensory trigeminal column (PrV and nTTD), ultimately reaches the motor nuclei via the reticular formation. The reticular formation forms the final link of three separate circuits: a telencephalic one entered through the principal trigeminal sensory nucleus, a cerebellar one via subnucleus oralis of the descending trigeminal system, and a direct one via subnucleus interpolaris. No direct connections between the principal trigeminal sensory nucleus or subnuclei of the descending trigeminal system and the motor nuclei of the trigeminal (NV) and facial (NVII) nerves have been observed, nor are such direct projections present in the outflow of the presumed telencephalic and cerebellar circuits, viz. of the archistriatum and the central cerebellar nuclei, respectively. The archistriatum projects via the occipitomesencephalic tract upon the lateral rhombencephalic reticular formation as far down as the rostral cervical cord, as well as upon the subnucleus interpolaris of the descending trigeminal system. Similarly, efferents from the central cerebellar nuclei reach the reticular formation, which in turn projects bilaterally upon the motor nuclei. Finally, commissural intermotor connections apparently are mediated by reticular cells surrounding the motor nuclei of NV or NVII, rather than emanating from these nuclei directly.

Afferent Pathways↗