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Biomedical subjects

E Dietrichs

Publications and source records attributed to E Dietrichs.

At least 37 records · Page 2Linked to original sources
PubMed1992

Cerebral blood flow findings in moyamoya disease in adults.

Three adult patients with moyamoya disease are described. They presented with intracerebral hematoma, cerebral infarction and subarachnoid hemorrhage, respectively. Subarachnoid hemorrhage is rare in moyamoya and is usually the result of aneurysm rupture. No aneurysm was found in our patient. Regional cerebral blood flow (rCBF) and the cerebral perfusion reserve assessed by the acetazolamide test, were significantly reduced in all three patients. The areas with most reduced baseline rCBF and most impaired vasoreactivity did not always correspond to the site of the vascular accident, indicating that these CBF changes were at least in part due to the moyamoya disease and/or its underlying causes, and not solely to the vascular accidents.

Adult↗
PubMed1992

The hypothalamo-cerebellar projection in the rat: origin and transmitter.

Hypothalamic neurons projecting to cerebellum were identified by retrograde tracing with wheat germ agglutinin-horseradish peroxidase (WGA-HRP) in the rat. Selective D-[3H]aspartate labelling was used to investigate whether any of these connections may use excitatory amino acids as transmitters. The WGA-HRP experiments revealed that the hypothalamo-cerebellar fibers have their main origins in the lateral, dorsal and posterior hypothalamic areas, and the tubero-mammillary nucleus, while smaller numbers of cells were observed in tuber cinereum, the anterior hypothalamic area, and the periventricular and paraventricular nuclei. After injections of D-[3H]aspartate into the cerebellar cortex, intense labelling of the olivocerebellar climbing fiber system was observed, but hypothalamic cells were not retrogradely labelled with this selective tracer. The absence of D-[3H]aspartate labelling indicates that hypothalamo-cerebellar neurons lack specific uptake mechanisms for excitatory amino acids, but it does not entirely preclude the possibility that some of these hypothalamic neurons may use such transmitters. Many cerebellar projecting cells were located in the tubero-mammillary nucleus, which is known to contain histaminergic and GABAergic neurons, and it was concluded that part of the hypothalamo-cerebellar pathways may use histamine and/or GABA as transmitters. The transmitter remains unknown for other parts of the hypothalamo-cerebellar pathways.

Afferent Pathways↗
PubMed1991

A study of branching in the projection from the inferior olive to the x and lateral c1 zones of the cat cerebellum using a combined electrophysiological and retrograde fluorescent double-labelling technique.

The pattern of transverse branching in the olivocerebellar projection to the x zone in the vermis and the lateral c1 zone in the paravermis of the cat anterior lobe was studied using a combined electrophysiological and retrograde double-labelling tracer technique. Fluorochrome-tagged latex microspheres were well suited for this purpose. The results show that the region of olive that supplies climbing fibres to the two zones forms a continuous, rostrocaudally directed column about 2.25 mm in length, in a caudo-lateral to rostromedial part of the medial accessory olive (MAO), on average between A-P levels 12.50-10.50. This column may be divided into caudal and rostral halves that project respectively to the x and lateral c1 zones in the apical folia of lobules V/VIa. Partial overlap between these two territories occurs in an intermediate region (A-P levels 12.00-11.00) in middle MAO where olive cells that supply climbing fibres to either x or lateral c1 are intermingled with a smaller population of cells whose axons branch to provide climbing fibres to both zones. Quantitative analysis showed that, when different tracers were injected into each zone in the same animal, double-labeled cells represented only 5-7% of either single-labelled cell population within this area of overlap. It is concluded that, although some transverse branching is present within the olivocerebellar projection to the x and lateral c1 zones in the apical folia of lobule V, such branching is not extensive.

Animals↗
PubMed1991

Evidence of an x zone in lobule V of the squirrel monkey (Saimiri sciureus) cerebellum: the distribution of corticonuclear fibers.

The distribution of corticonuclear fibers to medial-most parts of the posterior interposed nucleus (NIP) from lateral areas of the vermis was studied in the squirrel monkey (Saimiri sciureus), using a silver impregnation method. The origin and course of degenerated fibers were studied in serial sections. The distribution pattern of corticonuclear fibers from a series of small well localized lesions placed in the vermis and paravermal cortex of lobule V is compatible with the interpretation that an x zone is present in Saimiri. A comparison of the positions of lesions and the trajectory of fibers arising therein suggests that corticonuclear input to medial-most parts of the NIP originated from a narrow cortical area (about 0.5-0.7 mm wide) located between a cortical area projecting into the medial cerebellar nucleus (the A zone) and a laterally adjacent area (the B zone) which related to the lateral vestibular nucleus. This NIP-projecting cortical area, located about 1.7 mm to 2.5 mm off the midline in lobule V, is interpreted as the x zone in this primate; it extends from lobule IV into lobule VI in squirrel monkey. Corticonuclear fibers of zone x in this primate form a comparatively small terminal field in the medial-most portions of NIP. This contrasts with the distribution of corticonuclear fibers of the C2 zone which consistently distribute to terminal fields that are shifted into more central areas of NIP. There appears to be no overlap of the corticonuclear terminal fields in the NIP for zone x versus the C2 zone. These results were correlated with data from the literature on the distribution of olivocerebellar fibers to the x zone and the C2 zone and the arrangement of cerebellar nucleoolivary projections into the inferior olive from the NIP. The x zone and the C2 zone both receive input from the contralateral medial accessory olive (MAO), both zones project into the NIP, and the NIP projects into those regions of the MAO which, in turn, project to these respective cortical zones and into the NIP. This suggest that the x zone is a component of the NIP-MAO circuit. Furthermore the proposed function of the x zone would support the view that this sagittal strip may have a more extensive rostrocaudal distribution in primates as compared to the cat.

Animals↗
PubMed1991

Afferent connections to the abducent nucleus in the cat.

The afferent connections to the abducent nucleus in the cat were studied by means of retrograde transport of WGA-HRP after implantations of the tracer in crystalline form. Retrogradely labelled cells were found bilaterally in the medial and descending vestibular nuclei, mainly in their ventral and medial portions, in the rostral part of the ipsilateral gigantocellular reticular nucleus, in the medial part of the contralateral caudal pontine reticular nucleus and bilaterally in the oculomotor nucleus, mainly in its dorsolateral division. Some labelled cells were also found bilaterally in the mesencephalic reticular formation, the periaqueductal grey and the nucleus of the trapezoid body.

Abducens Nerve↗
PubMed1991

"Pelvic girdle relaxation"--suggested new nomenclature.

The term "pelvic girdle relaxation" is not uniformly used. For better understanding of pelvic joint pain during and after pregnancy it is crucial to have commonly accepted definitions for the different conditions. A committee appointed by the Norwegian Medical Association suggests the term "physiological pelvic girdle relaxation" for the ligament relaxation that occurs during any pregnancy. Ligament relaxation that causes considerable pain and/or pelvic instability during pregnancy and/or puerperium (so that daily function is impaired) is termed "symptom-giving pelvic girdle relaxation". A pain condition in one or more of the pelvic joints outside pregnancy and puerperium is called "pelvic joint syndrome".

Female↗
PubMed1991

Anatomy of the pelvic joints--a review.

In adults, after the os ilium, os ischii and os pubis have joined together by ossification to form the os coxae, there is usually one joint between the hip bones ventrally (the pubic symphysis) and several more complex joints between the hip bones and os sacrum dorsally (sacroiliac, "axial sacroiliac" and accessory sacroiliac joints). These joints carry the weight of the upper part of the body, but they shall also enable pelvic distention during labour. Pathological conditions in these joints are common, and increased knowledge concerning their normal antomy is important for better understanding of these conditions.

Humans↗
PubMed1990

Neuronal connections between the cerebellar nuclei and hypothalamus in Macaca fascicularis: cerebello-visceral circuits.

The purpose of this study was to identify the basic pattern of interconnections between the cerebellar nuclei and hypothalamus in Macaca fascicularis. The distribution of retrogradely labeled cells and anterogradely filled cerebellofugal axons in the hypothalamus of M. fascicularis was investigated after pressure injections of a horseradish peroxidase mixture (HRP + WGA-HRP) in the cerebellar nuclei. Following injections in the lateral, anterior, and posterior interposed cerebellar nuclei retrogradely labeled cells were present in the following areas (greatest to least concentration): lateral and dorsal hypothalamic areas, dorsomedial nucleus, griseum periventriculare hypothalami, supramammillary and tuberomammillary nuclei, posterior hypothalamic area, ventromedial nucleus and periventricular hypothalamus, around the medial mammillary nucleus, lateral mammillary nucleus, and infundibular nucleus. Cell labeling was bilateral with an ipsilateral preponderance. In these same experiments anterogradely labeled cerebellar efferent fibers terminated in the contralateral posterior, dorsal and lateral hypothalamic areas, and the dorsomedial nucleus. In these regions retrogradely labeled hypothalamic cells were occasionally found in areas that also contained anterogradely filled cerebellar axons. This suggests a partial reciprocity in this system. In addition, sparse numbers of labeled cerebellar fibers recross in the hypothalamus to distribute to homologous areas ipsilateral to the injection site. Subsequent to an injection in the medial cerebellar nucleus (NM), cell labeling was present in more rostral hypothalamic levels including the lateral and dorsal hypothalamic areas, the dorsomedial nucleus, around or in fascicles of the column of the fornix, and in the periventricular hypothalamic area. Although no fastigiohypothalamic fibers were seen in this study, on the basis of information available from the literature it is likely that such a connection exists in primates. In summary, hypothalamic projections to NM originated mainly from rostral to midhypothalamic levels, whereas those projections to the lateral three cerebellar nuclei came from mid and more caudal levels. The existence of direct hypothalamic projections to cerebellar nuclei in M. fascicularis and of cerebellofugal projection to some hypothalamic centers indicates that circuitry is present through which the cerebellum may influence visceral functions. Furthermore, the fact that projections to NM versus the other cerebellar nuclei originate from somewhat different regions of the hypothalamus would suggest that the visceral functions modulated by each pathway is not the same.

Animals↗
PubMed1990

The olivocerebellar projection to lobules I and II.

The olivocerebellar projection to lobules I and II was studied by means of retrograde transport from implants of the crystalline WGA-HRP complex. Retrogradely labelled neurons were found in the medial and dorsal accessory olives. Judged from the distribution of labelled cells, we conclude that parasagittally the olivocerebellar terminal zones A and B (i.e., the cerebellar cortical strips receiving axons from the olivary A and B regions) extend anteriorly into lobule Ia, whereas the fused olivocerebellar terminal C1/C3 zones reach lobule IIa. The olivocerebellar terminal C2 zone extends into lobule IIIa but not into lobule IIa. In lobule I the medial border of the B zone lies about 1 mm from the midline, in lobule II the B zone extends somewhat more medially. The lateral border of this zone is 1.9-2 mm from the midline. Compared to previous results, it appears that most of the Purkinje cells in lobule I projecting to the vestibular nuclei lie medially to the olivocerebellar terminal B zone.

Animals↗
PubMed1989

Interconnections between hypothalamus and cerebellum.

The cerebellum and hypothalamus are interconnected through a multitude of direct (monosynaptic) and indirect (polysynaptic) pathways. Direct hypothalamocerebellar fibres are mainly uncrossed and reach all parts of the cerebellar cortex and nuclei. They are neither mossy fibres nor climbing fibres, but appear to terminate in all layers of the cerebellar cortex as multilayered fibres. At least some of the hypothalamocerebellar fibres are histaminergic, and it appears that a small proportion of the hypothalamocerebellar neurons contain GABA. Indirect hypothalamocerebellar connections may be relayed through various brain stem nuclei. The hypothalamo-ponto-cerebellar pathway, which has a contralateral predominance, appears to be the quantitatively most important of these. The direct cerebellohypothalamic projection originates from the cerebellar nuclei and terminates in the posterior hypothalamus, in the same regions where the direct hypothalamocerebellar pathway has its main origin. Indirect cerebellohypothalamic connections with brain stem relays have also been demonstrated. The functions of hypothalamocerebellar circuits are so far unknown. However, these pathways are probably involved in the coordination and integration of somatic as well as non-somatic responses to a given set of inputs.

Animals↗
PubMed1989

Nonsomatic cerebullar circuits: a broader view of cerebellar involvements in locomotion.

The cerebellum not only receives extensive proprioceptive input from the periphery but also has bidirectional monosynaptic connections with the hypothalamus. This latter structure, in turn, is reciprocally interconnected with brain-stem visceral centers that also project to the cerebellum. Through these connections, information derived from somatic receptors that arrives at the cerebellum can directly influence visceral centers and circuits. It is suggested that the visceral responses seen during locomotor activity can be continuously monitored and partially regulated through such connections.

Journal Article↗
PubMed1988

The interconnection between the vestibular nuclei and the nodulus: a study of reciprocity.

The reciprocal connections between the nodulus and the vestibular and perihypoglossal nuclei in the cat have been studied by anterograde and retrograde transport after implants of crystalline wheatgerm agglutinin-horseradish peroxidase complex (WGA-HRP) restricted to one or two nodular folia. The findings supplement the previous study by Epema et al. (Neurosci. Lett., 1985, 57: 273-278), who injected WGA-HRP into the vestibular nuclei. In that study, details concerning the nodular origin and termination of the fibres within the reciprocal connections were given; in the present study, details are given concerning the origin and termination of the fibres within the vestibular and perihypoglossal nuclei. Our observations give evidence that the nodulovestibular fibres are distributed to a somewhat larger area than that projecting back to the nodulus. The distribution of the labelled cells and fibres is shown in Fig. 2. Of the 4 main nuclei, it is only the lateral vestibular nucleus which is devoid of a reciprocal connection with the nodulus, while only groups x and z of the minor cell groups are found to have such projections. Of the perihypoglossal nuclei, it is only the nucleus praepositus hypoglossi which appears to be interconnected with the nodulus.

Afferent Pathways↗
PubMed1988

Cerebellar cortical and nuclear afferents from the Edinger-Westphal nucleus in the cat.

The cerebellar projection from the Edinger-Westphal nucleus was studied in the cat by means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex. The present findings give evidence that the flocculus is the main terminal area. However, small tracer implants and injections into various parts of the cerebellar nuclei and cortex revealed projections also to the fastigial and interposed nuclei and to most parts of the anterior and posterior lobe cortices. The projecting neurons are small and located bilaterally throughout the Edinger-Westphal nucleus. No topical differences between the projections to different parts of the cerebellum were found.

Afferent Pathways↗
PubMed1988

The feline oculomotor nucleus: morphological subdivisions and projection to the cerebellar cortex and nuclei.

The cytoarchitecture of the feline oculomotor nucleus was examined in sections stained with thionin and neutral red. Five different subdivisions (caudal central, paramedian, ventral, dorsomedial and dorsolateral divisions) can be identified on each side of the midline. This observation is discussed, and our findings are compared to previous studies of the cytoarchitecture or central muscular representation of the oculomotor nucleus in which different subgroups have been distinguished. Implants or injections of the wheat germ agglutinin-horseradish peroxidase complex have revealed that all five subdivisions project to different parts of the cerebellar cortex and nuclei. Retrogradely labelled cells were found in the oculomotor nucleus in 18 cases following deposition of tracer in the fastigial and interposed nuclei and certain regions of the anterior, posterior and flocculonodular lobes. The projection is bilateral and appears to have its main termination in flocculus. It originates from small neurons, especially from those located along the dorsal border of the oculomotor nucleus.

Afferent Pathways↗
PubMed1988

Cerebellar cortical and nuclear afferents from the feline locus coeruleus complex.

The origin and distribution of cerebellar cortical and nuclear afferents from the locus coeruleus complex (the nucleus locus coeruleus, the nucleus subcoeruleus, the medial and lateral subdivisions of the parabrachial nucleus and the Kölliker-Fuse nucleus) have been studied by means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex in the cat. Cerebellar cortical depositions of the tracer were made by pressure injections, while nuclear depositions were made by implanting the tracer in crystalline form. The projection is bilateral with an ipsilateral preponderance. It reaches all the cerebellar nuclei as well as vermal, intermediate and lateral parts of the cerebellar cortex. The highest cell counts were made after tracer depositions in vermal and intermediate parts of the cerebellum. The projection in the cat has a more widespread origin than previously reported. It originates mainly within the nucleus locus coeruleus and the parabrachial nucleus (especially in its lateral subdivision), but retrogradely labelled neurons were also found in nucleus subcoeruleus, the Kölliker-Fuse nucleus and the A4 cell group. The cells of origin were of different shapes, but usually had a maximum diameter of the cell body between 15 and 30 micron. Cerebellar efferent axons passing through the locus coeruleus complex were anterogradely labelled following implants in all the cerebellar nuclei, but definite terminal labelling was not observed within the nuclei of the locus coeruleus complex.

Animals↗
PubMed1988

Demonstration of a sparse direct projection from the interstitial nucleus of Cajal to the cerebellum in the cat.

In the cat the possible contribution of cerebellar afferents from the accessory oculomotor nuclei was investigated by means of retrograde transport of the wheat germ agglutinin-horseradish peroxidase complex. A sparse bilateral projection from the interstitial nucleus of Cajal was demonstrated. The fibres reach cerebellar cortical as well as nuclear regions. No retrogradely labelled cells were found in the nucleus of Darkschewitsch and the nucleus of the posterior commissure.

Animals↗
PubMed1987

The olivonodular projection: a re-examination based on folial cerebellar implants.

In 5 cats implants of crystalline wheat germ agglutinin-horseradish peroxidase complex were placed in one or two folia of the nodulus with no contamination of adjacent cerebellar lobules. In the inferior olive only the dorsal cap with the adjacent ventrolateral outgrowth and the caudalmost part of nucleus beta were found to project to the nodulus. Negative findings were consistently made in all other parts of the inferior olive, some of which have previously been described to contribute to the olivonodular projection.

Animals↗