Harold H. Traurig

Synaptophysin and synaptoporin expression in the developing rat olfactory system

The expressions of two closely related synaptic vesicle antigens synaptophysin and synaptoporin were examined in the olfactory system of the adult rat and during pre- and postnatal development. In the adult, immunocytochemistry showed that the continuously regenerating olfactory receptor neurons (primary neurons) produce both synaptophysin and synaptoporin which were localized in the cell bodies of the receptor neurons in the olfactory epithelium, their dendrites, axonal processes in the olfactory nerve and their terminals in the olfactory bulb glomeruli. Furthermore, ultrastructural analysis revealed synaptophysin- and synaptoporin-immunoreactivities associated with synaptic vesicles in most olfactory receptor axonal terminals impinging on dendrites of the mitral and tufted neurons (secondary neurons in the olfactory bulb circuitry) in the olfactory glomeruli. In like manner, tufted neurons, granule and periglomerular neurons (interneurons in the olfactory bulb circuitry) express both synaptophysin and synaptoporin. In contrast, mitral neurons expressed only the synaptophysin antigen which was likewise associated with mitral axonal terminals in their target the olfactory cortex. The patterns of synaptophysin and synaptoporin expressions in mitral neurons (synaptophysin only) and tufted neurons (synaptophysin and synaptoporin) were similar in prenatal, postnatal and adult rats as revealed by immunocytochemistry and in situ hybridization. However, the biosynthesis of synaptophysin and synaptoporin by granule and periglomerular neurons, olfactory bulb interneurons, occurred mainly postnatally.

Distribution of FMRF-NH2-like immunoreactivity in rat and cat area postrema

The distribution of FMRF-NH2-like immunoreactivity, visualized with immunohistochemical techniques, was plotted in a range from very dense to none. The rat area postrema had differential immunostaining with the greatest amounts occurring at its ventral and ventrolateral borders by the nucleus of the solitary tract. Immunoreactive cell bodies were located mainly in this region. Throughout the central region of the rat area postrema scattered immunostaining was consistently observed. The cat area postrema had a different, greater, and more complex pattern of immunostaining than the rat. Very dense to dense accumulations of immunostaining occurred in the ventromedial region of the area postrema bordering the solitary tract and dorsal vagal nuclei, while the central region possessed scattered amounts of immunoreactivity. Following colchicine treatment, no visible FMRF-NH2-like immunoreactive cell bodies were observed in the cat area postrema.

Healing following condylar shave in the monkey temporomandibular joint

Condylar shaves were performed in monkeys, and the reparative process was studied by histologic and autoradiographic techniques. The condylar surface was found to repair mainly with fibrous connective tissue produced by cells derived from the underlying marrow spaces. The residual condylar cartilage did not play a significant role in this process.

Lysosomal acid hydrolase activities in the lungs of fetal, neonatal, adult, and senile mice.

The activities of four lysosomal acid hydrolases (LAH) in the lungs of two strains of mice changed significantly throughout the life cycle. In the CK7B1/6J animals, acid phosphatase (AP) and beta-glucuronidase (beta-G) were maximally active during early neonatal life then gradually declined the adult levels by 4-5 weeks of age. After reaching the adult level, acid phosphatase activities did not change significantly tcreased markedly with advanced age. N-Acetyl-beta-D-glucosaminidase (GAD) activities did not change significantly duringlate fetal, neonatal or young adult stages but increased significantly with advancing age. In the lungs of the CFW animals, the increase in activities of beta-G and GAD between young adult life and advanced age was highly significant, whereas there was no notable change in the activities of acid phosphatase or arylsulfatase (AS). The specific activities of the hydrolases in the lungs of the C57B1/6J strain were quite similar to those in the lungs of the CFW strain. The activities of all four hydrolases were markedly elevated in two spontaneous adenomatous tumors found in the lungs of old mice. The data indicate that LAH play a significant role in lung growth and maturation, and in changes associated with aging.

Appearance of strand breaks in the nuclear DNA of terminally differentiating vaginal epithelium

Abstract Calf-thymus terminal deoxynucleotidyl transferase-catalyzed reaction was applied to sections of ethanol-fixed mouse vaginal epithelia. As terminally differentiating epithelial cell-nuclei undergo pycnosis, they show increasing amounts of initiator activity for this enzyme indicative of the appearance and accumulation of strand breaks in the nuclear DNA.

Ontogenic development of secretogranin II and of its processing to secretoneurin in rat brain

The ontogenic development of secretogranin II was studied by immunochemistry and immunohistochemistry. Extracts of brains from various developmental stages were analyzed by a radioimmunoassay for secretoneurin, a peptide derived from secretogranin II. From gestational day 13 to adulthood the levels increased from 0.1 to 94 fmol/mg wet weight. Characterization of the immunoreactivity by molecular sieve chromatography revealed that throughout all developmental stages the proprotein secretogranin II was fully processed to the free peptide secretoneurin. In immunohistochemistry secretoneurin-IR was first detected at embryonic day 13. Between embryonic days 14 and 18 a strong increase in the number of secretoneurin immunopositive cells was observed in many brain areas, notably in the amygdala, hypothalamus, olfactory bulb and several brainstem nuclei. The pattern of staining during development is quite similar to that in the adult. The present paper demonstrates that secretoneurin immunoreactivity appears early in embryonic life. Processing of the proprotein secretogranin II starts when the protein is first synthesized apparently at about the same time when the prohormone convertase PC1 and PC2 can be demonstrated.

Lysosomal acid hydrolase activities in the aging heart

Abstract Total activities of four lysosomal acid hydrolases in the hearts of aging mice have been studied. Hydrolase activities were assayed in whole hearts of male C57B1/6J mice at 2.5, 5, 11, 17, 21 and 27 months of age and were expressed as μmoles substrate hydrolyzed/h/mg protein. β-glucuronidase and arylsulfatase (A & B) activities increased linearly with age. Maximum activities of β-glucuronidase and arylsulfatase were observed at 27 months of age and were 35 and 38% higher respectively compared to activities at 2.5 months. N -acetyl- β -D-glucosaminidase activities changed with age in quadratic fashion. Activities at 2.5 months of age declined 20% by 5 months and then increased by 45% to a maximum by 27 months. Acid phosphatase activities did not change significantly through the age span studied. These results are correlated with electron microscopic observations on the accumulation of lipofuscin pigment granules with age in the myocardium. These observations suggest that the increased activities of certain lysosomal hydrolases during the life span and the accumulation of lipofuscin are positively correlated and that they may play an important role in the aging heart.

Students' responses to the introduction of a digital laboratory guide in medical neuroscience

This study investigated student acceptance of a digital laboratory guide in a medical neuroscience course. The guide was created in Macromedia™ Authorware 5.2 by transforming a text-based lab manual into a comprehensive multimedia program. Student attitudinal survey data indicated that the guide was used primarily as a study tool at home. Some 53% of students (primarily males) used the guide for independent study exclusively, while the remainder used it for both independent and group study; 87% of the class used the guide as a routine study tool rather than as a final review for examinations. Most students perceived that the guide increased their study efficiency and lab performance while decreasing their out-of-class study time in the lab. Female students were significantly more enthusiastic about the guides impact on their study efficiency, lab performance and laboratory study time. Gender differences in student satisfaction with and use of instructional multimedia are discussed.

Equipment for Simultaneous Processing of Groups of Slides for Radioautography

The equipment consists of commercially available 5-slide plastic grips (obtained from Lipshaw Manufacturing Co., 7446 Central Ave., Detroit, Mich. 48210) and specially designed lightproof exposure boxes to hold the grips. After deparaffinization and hydration, slides are inserted into the grips, dipped in liquid emulsion, drained, and sealed in the exposure box. After exposure, the 5-slide units are removed from the box (in darkness) and inserted into specially made Plexiglas racks that hold four 5-slide units (20 slides). Photographic developing, fixing, and washing are performed by immersing the 20-slide group in fluids contained in 30-slide glass staining dishes (Lipshaw No. 122 dishes). The equipment simplifies darkroom operations and provides means for standardizing the preparation of radioautographs.

A preliminary study of reconstruction of the monkey temporomandibular joint with autogenous tissues.

PURPOSE This study investigated the ability of autogenous pericranium-muscle and cranial bone to restore form and function of the temporomandibular joint (TMJ). MATERIALS AND METHODS A right TMJ discectomy, condylectomy, vertical ramus osteotomy with superior repositioning of the proximal fragment, and a cranial bone graft to the mandibular angle were performed in 12 cynomolgus monkeys. Clinical, histologic, and autoradiographic evaluation was done at intervals beginning at 3 days and continuing up to 78 weeks. RESULTS No significant postoperative sequela were identified in any of the monkeys. Jaw mobility and function were restored. Gross morphologic condylar changes were observed. The pericranium-muscle grafts did not differentiate into normal disc-like structures and a cartilage cap did not cover the condyle stump head. CONCLUSIONS The results of this study suggest that the previous TMJ function was restored. However, the histologic changes observed were consistent with advanced degenerative joint disease.