Sphenoidal artery, ramus orbitalis persistens and pterygospinosus muscle--a unique cooccurrence of first branchial arch anomalies in man.

In a 76-year-old Caucasian male, the right middle meningeal was replaced by a branch of the ipsilateral ophthalmic artery (O), i.e. the sphenoidal artery (S); the right foramen spinosum was found to be absent. In the orbit, the right O bifurcated into a medial (merely orbital) and a lateral division, i.e. a meningolacrimal trunk. From that trunk, the S branched off and entered the middle cranial fossa at the superolateral angle of the superior orbital fissure. In addition, an anastomotic channel was formed by a remnant of the ramus orbitalis, connecting the right infraorbital with the deep orbital artery. The right accessory meningeal (AM) regularly arose from the maxillary artery and entered the cranial cavity through the foramen ovale, separated from the mandibular nerve by a pterygospinosus muscle. This muscle was merely present in the right infratemporal fossa. Interestingly, the left AM originated from the posterior deep temporal artery. No other anatomical variations were found in this individual. Since the coexistence of an S with variations of other structures derived from the first branchial arch has not been previously reported in man, the embryology and comparative anatomy of this irregular vessel are discussed.

Unilateral persistence of the dorsal ophthalmic artery in man.

The left ophthalmic artery (OA) of a Caucasian male originated from the transverse portion of the cavernous part of the internal carotid artery (ICA), indicating the persistence of a dorsal OA. It entered the orbit through the most medial part of the superior orbital fissure, close to the medial aspect of the ophthalmic nerve. In the orbital cavity, the OA crossed above the optic nerve to reach the medial wall of the orbit. At the medial end of the upper eyelid it anastomosed with the angular artery and thereafter divided into the dorsal nasal and supratrochlear arteries. Whereas the right OA did not present any irregularities, some additional anatomical variations, above all a bilateral pterygospinosus muscle, were found in this individual. Since except the existence neither the course and branching pattern of a persistent dorsal OA nor its occurrence together with other varieties have been previously reported in man, phylogenetic and ontogenetic aspects of this aberrant vessel are discussed.

A bilateral maxillofacial trunk in man: an extraordinary anomaly of the carotid system of arteries.

In a Caucasian male, the maxillary artery (M) bilaterally arose with the facial artery anteromedially from the external carotid artery. On the right side, the M entered the infratemporal fossa between the neck of the mandible and the medial pterygoid muscle, whereas the left M pierced the medial pterygoid muscle, first being covered by the muscle and the angle of the mandible. On both sides, the M ran deep to the inferior head of the lateral pterygoid muscle and the buccal nerve. The right M lay deep to the inferior alveolar, but superficial to the lingual nerve, whereas the left inferior alveolar and lingual nerves had formed two roots, thus encircling the left M. The ascending palatine artery was replaced on both sides by palatine branches of the ascending pharyngeal artery. Since a bilaterial maxillofacial trunk with topographical relations as described herein has not been previously reported in man, the embryology and comparative anatomy of this variation are discussed.

Complex anomalies of the human aortic arch system: unique case with both vertebral arteries as additional branches of the aortic arch.

We describe a case of an aortic arch with five primary branches arising in a sequence that has previously never been reported. From right to left, the brachiocephalic trunk and left common carotid, left vertebral, and subclavian arteries originated from the convexity of the aortic arch. The last branch was the right vertebral artery that arose from the dorsal aspect of the aortic arch opposite the ligamentum arteriosum. Presenting a dilatation at its commencement, the right vertebral ran to the right behind the esophagus and entered the foramen transversarium of the seventh cervical vertebra, whereas the left vertebral passed to the foramen transversarium of the fifth cervical vertebra. The left vertebral artery gave off the left thyroid artery; a thyrocervical trunk was absent on the left side. A thyroidea ima arose from the brachiocephalic trunk. The embryology of this complex anomaly as well as its potential clinical significance are discussed.

[Central localization of motor components in the internal branch of the superior laryngeal nerve: a horseradish peroxidase study in the rat]. / Zentrale Lokalisation motorischer Komponenten im Ramus internus des N. laryngeus superior: Eine HRP-Studie bei der Ratte.

The central organisation of the internal branch of the superior laryngeal nerve was examined in the rat using the technique of intraaxonal transport of horseradish peroxidase (HRP). Application of HRP to the internal branch resulted in anterograde labelling of afferent nerve fibres as well as in retrograde labelling of perikarya within both motor nuclei of the vagus, i.e. the nucleus ambiguus and the dorsal motor nucleus. The location of retrogradely labelled neurons is confined to an area of 700 microns length near the rostral extremities of both nuclei. The internal laryngeal branch, therefore, is not entirely sensory, but contains general and special visceral efferent fibres arising in the dorsal motor nucleus and in the nucleus ambiguus, respectively. Dorsal motor neurons of the internal branch represent preganglionic parasympathetic neurons projecting to the mucous glands of the larynx, whereas efferents from the nucleus ambiguus supply striated muscle fibres of the larynx. The arytenoid and aryepiglotticus are discussed as potential targets of the internal branch of the superior laryngeal nerve.

Horseradish peroxidase histochemistry on mounted sections from embedded specimen: a simple method for serial reconstruction of neuronal projections.

A combination of two procedures, embedding of specimens and horseradish peroxidase (HRP) histochemistry on mounted serial sections, is proposed for three-dimensional reconstruction of neuronal projections. To clarify the intrinsic organization of the peripheral nervous system, this simple method is more adequate than previously used techniques.

The human thyrocervical trunk: configuration and variability reinvestigated.

Reinvestigation of the configuration of the human thyrocervical trunk revealed, that in the presently investigated specimens the dorsal scapular artery is a direct branch of the subclavian artery in approximately 75% of the cases, whereas in the remaining 25% it is derived from the thyrocervical trunk, either directly or via the transverse cervical artery (Nomina anatomica 1977). The internal thoracic artery participates in the thyrocervical trunk in more than 10% of the observed cases. Thus, both dorsal scapular and internal thoracic artery have to be considered as facultative branches of the thyrocervical trunk. According to our results, the subclavian artery must be considered as the most common site of origin of the dorsal scapular artery. This vessel may be replaced by another artery in about one fourth of the cases. A survey of studies on the origin of the dorsal scapular artery clearly demonstrates that it is not warranted to give an overall numerical proportion for the main modes of branching. As yet no satisfactory explanation for the high degree of variability of these subclavian branches has been given. Especially the widely held notion of differences related to race, which is based on Adachi's (1928) work, has turned out to be invalid. Interpretation of variability may rather be based, as a general concept, on the late acquisition of a thyrocervical trunk in phylogeny as well as in ontogeny.

[Controlled dissecting laboratory trial of different phenol-free-embalming fluids in comparison with phenol-formalin-solution (author's transl)]. / Zur Präparatequalität von anatomischen Studienleichen: Vergleich verschiedener phenolfreier Rezepturen mit der klassischen Phenol-Formalin-Methode.

Phenyl and formaline, which are contained in a series of embalming fluid formulas, are considered to be disadvantageous in some respect. Different approaches were envisaged in order to minimize risks and to maintain a safe and suitable condition of specimens. Concentrations of phenol and formaldehyde in our customary formula were reduced to 4.1 and 0.82% respectively. Quality of specimen, which had been preserved with this fluid, was compared with that obtained with different phenol-free formulas in standardized dissecting laboratory trials. Best results were registered in bodies preserved with a solution containing ethanol, formaline and glycerine (Tutsch 1975). Quality of specimens preserved with phenol/formaline did not fall short of these to a decisive degree, whereas other solutions (Jores 1913; Neumann 1974) turned out to yield less desirable effects. Successful substitution of preservation with phenol proved to be practicable. Nevertheless high cost of alternative fluids prevented the substitution of our traditional phenol/formaline solution at large scale. In addition to results on comparison of effects of different embalming fluids a survey on our experience with consequent low-pressure injection of bodies and with a new storage system is given.

Anterograde and transsynaptic degeneration 'en cascade' in basal ganglia induced by intrastriatal injection of kainic acid: an animal analogue of Huntington's disease.

Damage of striatal neurons by kainic acid (KA) induces an anterograde and transsynaptic degeneration 'en cascade' in the globus pallidus (GP) and substantia nigra (SN). By causing only degeneration of projections arising from KA-sensitive striatal neurons while sparing the connections of KA-resistant striatal neurons, the lesion-induced alterations of the basal ganglia show a characteristic pattern which bears a close resemblance with the neuropathological changes occurring in Huntington's disease: (1) severe degeneration of small and medium-sized striatal neurons, of pallidal neurons and the neurons of the pars reticulata of the SN, and (2) sparing of large striatal neurons, 'peripallidal' (nucleus basalis) neurons and neurons of the pars compacta of the SN. The probable interconnections of both the degenerated and the spared neuronal groups are discussed with respect to the present concept of the neuronal organization and biochemical neuroanatomy of the basal ganglia.

Neurotoxicity of kainic acid: evidence against an interaction with excitatory glutamate receptors in rat olfactory bulbs.

The hypothetical interaction of kainic acid (KA) at excitatory glutamate (GLU) receptors was tested by injecting this neurotoxin into the olfactory bulb (OB), since the putatively GLUergic output neurons of the OB are among the few neurons in the CNS that are not excited by GLU. However, the mitral (and tufted) cells are found to be highly and preferentially destroyed by KA, whereas the GLUreceptive interneurons of the OB appear to be relatively resistant to the neurotoxin. These findings suggest that the toxic effect of KA on OB neurons may be mediated by mechanisms other than by action on GLUreceptors.

[Microbiological monitoring of embalmed cadavera during dissection courses (author's transl)]. / Mikrobiologische Uberwachung von konservierten Studienleichen während des anatomischen Präparierkurses.

Microbiological monitoring of normal anatomical specimens was done in order to evaluate results which were obtained in a investigation of decay of embalmed cadavera. The process of decay was characterized by massive colonisation with enterobacteria and aerobic sporeformers. Under normal conditions mainly germs from skin and air are cultivated from surfaces of anatomical specimens, but only in small numbers. The number of germs is increased after periods of intensive preparative work. The results show that the main criterion for the microbiological quality of embalmed cadavera is resistency against external germs during course work. This is to be achieved by consequent preventive measures in the dissection laboratory.

[Comparison of disinfectant activity of 3 different embalming fluids on cadavera for anatomical study (author's transl)]. / Vergleichsuntersuchungen der Desinfektionswirkung verschiedener Konservierungslösungen für Anatomieleichen.

The antimicrobial effect of 3 different embalming fluids (Phenol/Formaline, JORES 1913 TUTSCH 1975) was evaluated from the beginning of the conservation process through storage in a new system (TUTSCH et al. 1971) and the subsequent dissection course. Endogenous bacteria are significantly reduced 24 hours after injection. Later on during the storage period of at least 6 months no germs are detected in swabs from orifices whereas Staphylococcus epidermidis and aerobic sporeforming bacteria were found on the surfaces of the bodies in some cases. The formula of the disinfectant (Phenol/Formaline or Merfen according to NEUMANN 1974) in the storage system appears to be of no significance. During dissection as a rule Staphylococcus epidermidis and a few aerobic sporeformers were found on the surface of specimens, at one time Pseudomonas aeruginosa was cultivated too. Swabs from the peritoneal cavity and from contents of the intestine were sterile. Investigations by broth dilution method were carried out in order to evaluate the degree of bacteriostatic activity of the various fluids in use. This method is now routinely used for control of the disinfectants in the storage system.

Carotid body chemoreceptor function: hypothesis based on a new circuit model.

Integration of our own morphological observations into recent ultrastructural, biochemical, and neuropharmacological results on the carotid body led to a new hypothesis on chemoreceptor function: (i) Glomus cells with small dense-cored vesicles (type IB cells) that store norepinephrine are chemoreceptors. (ii) Glomus cells with large dense-cored vesicles (type IA), which are postsynaptic to the other glomus cell type and presynaptic to afferent nerve endings, are dopaminergic interneurons that suppress the afferent discharge frequency during normoxia by releasing dopamine. (iii) The hypoxic stimulus causes the chemoreceptive cell to release the stored norepinephrine, which in turn brings about disinhibition of the afferent nerve endings by inhibition of the interneuron. (iv) Afferent nerve endings and interneurons interact through reciprocal synapses that form a short inhibitory feedback loop. We propose that information in the carotid body is processed in a fashion graded rather than digital, providing a fine adjusted cooperation of all elements.

Effect of zinc ions on structure and distribution of neurotubules (author's transl). / Effekt von Zinkionen auf Struktur und Verteilung der Neurotubuli

Being interested in factors stabilizing neurotubules (NTs) in situ, we decided to immerse short segments of fresh rat peripheral nerves in buffered solutions containing ZnCl2 in final concentrations up to 10-2 m prior to fixation with buffered osmium or glutaraldehyde, both containing ZnCl2. Zinc treatment resulted in a remarkable structural preservation of NTs after fixation with osmium, though they are not preserved by osmium fixation alone. Cross sections of myelinated nerve fibres show NTs arranged predominantly in compact groups. Within the groups NTs are surrounded or embedded in an electron dense fine granular material. The occurrence of incomplete C-shaped NTs and NT-like densities can be seen. NTs exhibit relatively constant distances and sometimes geometric patterns of arrangement. A lot of intertubule cross bridges and NTs with arms could be observed. In longitudinal section the bridge and arm spacing is seen to be periodic along the tubule axis at about 500 A. Zinc treatment of nerves fixed in glutaraldehyde resulted in the same ultrastructural alterations described above. The resistance of zinc-stabilized NTs to degradation by osmium and the ultrastructural changes induced by zinc are discussed. The results suggest that in the presence of zinc ions osmium-labile NTs are transformed--by disassembly and reassembly--to osmium-stabile microtubules that are not identical with preexisting ones.