Lack of effect of neurotransmitters on cyclic AMP phosphodiesterase activity in an insect CNS

Summary The inhibition of cyclic nucleotide phosphodiesterase from the nerve cord ofManduca sexta was studied using theophylline as a model compound. 11 putative neurotransmitters had no effect on enzyme activity.Supported in part by NIH grant NS-09161-20 to R. W. Newburgh     

Antagonism of amphetamine stereotyped behavior by diastereoisomeric dihydrodibenzothiepin neuroleptics

Summary Differences in neuroleptic activity were observed between the diastereoisomers of a dihydrodibenzothiepin derivative, while no potency differences were seen between their respective enantiomorphs.Supported by USPHS grant NS-10203.     

Is serotonin or are its metabolites responsible for induction of hypothermia?

Summary Serotonin per se, rather than its metabolites, was shown to produce hypothermia in mice. This effect was mediated within the CNS and could be attenuated by methysergide.This study was supported in part by grants No. NS-12759 and No. AA-2696 from the USPHS and a research grant from the Graduate College of the University of Illinois.     

Depletion of synaptic vesicles at the frog (Rana pipiens) neuromuscular junctions by tetraphenylboron

Summary At the frog neuromuscular junction tetraphenylboron produced a decrease in miniature endplate potential amplitude, accompanied by a decrease in the number but not the size of synaptic vesicles.This work was supported by NIH Grants Nos NS-07740 and NS-05707 to R. L. P. and was done during the tenure of a Research Fellowship of Muscular Dystrophy Associations of America, a Wellcome Research Travel Grant and a grant from the Carnegie Trust for the Universities of Scotland to I. G. M. The assistance of Dr.R. M. Schnitzler, W. G. Boldosser andP. M. Spannbauer is gratefully acknowledged.     

Ionic effects on cyclic nucleotide accumulation in a phytophagous insect

Summary Incubation in solutions containing high potassium levels reduces specific accumulation of cyclic AMP in larval nerve cords ofManduca, sexta in vitro with or without serotonin or theophylline.Supported in part by NIH grant NS-09161-20 to R.W.N.     

Effects of neuromuscular blockers on carnosine levels in rat skeletal muscle

Summary A 30-min treatment with neuromuscular blocking doses of either physostigmine or d-tubocurarine was associated with a 44% or 36% (respectively) reduction in rat skeletal muscle carnosine levels in vivo.This work was supported by grant NS-06137 of the National Institute of Health.     

Motor nerve terminal defect following tenotomy

Summary Post-tetanic potentiation and the underlying post-tetanic repetition in cat soleus muscle require normal motor nerve terminals. These indices of nerve terminal viability are depressed 10 days and absent 15 days after tenotomy of the soleus muscle.Supported in part by NIH grant NS-11948.     

Carnosine levels in blood

Summary Carnosine levels were determined in chick erythrocytes (2510 nmoles/g cells) and plasma from chick (27 nmoles/ml), rat and rabbit. Carnosine was also measured in rabbit reticulocyte-rich blood (105 nmoles/g cells), normal blood (18 nmoles/g cells) and in bone marrow.This work was supported by grant NS-06137 of the National Institutes of Health.     

Stereotaxic technique for transplantation of neural tissues in the brain of adult rats

Summary A technique of neural transplantation in the brains of adult animals, using stereotaxic apparatus, is described. It facilitates transplantation of neural tissues of small volumes in precisely defined structures of the host brain, and yields a high percentage of successful transplantations.Supported by N.I.H. Research grant No. NS-08817. Suggestions from Drs N. Mangini, M. M. Oblinger and J. Weibers on various aspects of this procedure are gratefully acknowledged.     

Neurons with dual axons in the substantia gelatinosa (SG) of the adult cat lumbosacral spinal cord

Summary A small percentage of SG neurons possessing two separate and complete axons were observed in the lumbosacral spinal cord of the adult cat. Since they are found in small numbers and are structurally similar to single axon SG cells, dual axon cells may represent a developmental aberrancy rather than a functionally distinct cell type.This research was supported by U.S.P.H.S. grant No.NS-16642-01.     

Binucleated neurons in the central nervous system of the laboratory animals

Summary Binucleated neurons were studied in the central nervous system of the rat and the rabbit. They were present in the young as well as the adult animals. The animals injected with thymidine-H³ during their embryonic development showed labelled binucleated neurons. It is suggested that the neurons become binucleated during neuroembryogenesis, and differentiate into normal neurons morphologically and physiologically.Supported by NIH Research grant No. NS-08817-05.     

Rat sternothyroid muscle: Dissection and preparation for electrophysiologic and electronmicrographic studies

Summary The sternothyroid muscle of the rat is described. The ease of dissection and localization of end-plate regions within the sternothyroid muscle by direct visualization of nerve supply provides a convenient mammalian muscle preparation for electrophysiological and ultrastructural research.This research was supported in part by the following grants: PHS 5429-16-20 (to C. M. Poser), NIH grant NS-07740 (to R. L. Parsons).We express our appreciation to Drs C. M. Poser and R. L. Parsons for providing us with laboratory space and equipment to conduct these experiments in addition to much helpful advice and criticism.     

Structural relationships between the endogenous volatile urinary metabolites of experimentally diabetic rats and certain neurotoxins

Summary High resolution glass capillary gas chromatography and GC/MS were utilized to examine qualitative and quantitative variations from normal of urinary volatile metabolites of long-term alloxan and streptozotocin diabetic rats. Volatile metabolites were structurally compared with known neurotoxins to examine any possible relationship between these metabolites and the development of the diabetic polyneuropathy.Acknowledgment. This research was supported by grant No. 24349 from the National Institute of General Medical Sciences, U.S. Public Health Service.     

A simple method enabling standardized handling of small biological objects for light and electron microscopic preparation

Summary A glass filtration-apparatus provided with an exchangeable nylon-tissue filter permits collection, fixation, dehydration, staining and preembedding of small biological objects in a simple and rapid way.This work was supported by grant No 3.218.-077 of the Swiss National Science Foundation.     

Involvement of a surface concanavalin A-binding glycoprotein in the adhesion ofTrichomonas vaginalis to substrates

Summary Treatment ofTrichomonas vaginalis with EDTA removes their ability to adhere to glass surfaces and changes their affinity to Concanavalin A (ConA) by a different distribution of their surface structures. Filtrates of the EDTA-treatedTrichomonas passed through affinity chromatography columns (ConA bound to Sepharose 4B0 separate into 2 fractions, one fraction was bound to the ConA-Sepharose beads, the other was not. The Con A-bound fraction appears to be a glycoprotein which restores in a specific way the ability of the EDTA-treated protozoa to adhere to glass. We want to thank Dr.P. M. Comoglio for the donation of the FITC-labelled immunoglobulin fraction of anti-ConA rabbit antiserum. This work was supported by a grant from the Italian National Research Council (C.N.R.)     

The underwater electro-olfactogram: A tool for the study of the sense of smell of marine fishes

Summary Recording the olfactory receptor activity of marine fishes presents problems due to the shunting of the electrical signals by the highly conductive sea water, which results in significant signal loss. By recording the large signal-to-noise ratio D. C. potentials using the underwater electro-olfactogram (EOG), we were able to study olfactory receptor properties of freshwater and marine fishes in a comparable manner.This work was supported by grants from the National Institutes of Health, Nos. NS-08814 and NS-05258.     

Synaptic boutons in the hippocampus: Changes are produced by age and experience

Zusammenfassung Erstmaliger morphometrischer Nachweis bei 2 Gruppen reifer, altersunterschiedlicher Ratten, dass die Zahl der Synapsen im Hippocampus mit dem Alter zunimmt, wobei die effektive Steigerungsrate auch mit Umwelteinflüssen zusammenhängen könnte.

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This work was supported by grants from the U.S. National Institutes of Health to JJB (No. NS-06164) and to LEW,Jr., (No. NS-09358) and funds from the Center for Neurobiological Sciences of the University of Florida (No. NIH-MH-10320).     

In vitro interaction of enkephalin with serum and chromaffin granule components

Summary Incubation of radioactively labeled enkephalin with serum components or chromaffin granule components in vitro provided evidence that there are specific constituents which bind enkephalins and may affect their degradation. Evidence for carboxy-terminal degradation was found.This work was supported by the NIH Grants NS-13201 and NS-00201.     

Induction of electrical excitability in crustacean muscle by 4-cyclopentene-1,3-dione

Summary 4-Cyclopentene-1,3-dione induces electrical activity in inexcitable crustacean muscle. This effect is blocked by previous treatment with p-chloromercuribenzoic acid. These results suggest that crustacean muscle becomes excitable when certain-CH₂-SH side chains are converted to thioethers having carbonyl groups.Acknowledgments. This work was supported by USPHS Nos NS-07464, NS-14938 and GM-05784. Contribution No. 80 of the Laboratory of Neurobiology.     

Myoneural junctions in larval ascidian tail

Zusammenfassung Elektronenmikroskopische Untersuchungen der Neuriten in der Peripherie des dorsalen Nervenstranges im Schwanz der Aszidien-LarveAmaroucium constellatum zeigen, dass die in der Nähe liegenden Schwanzmuskelzellen Verbindungen mit den Neuriten eingehen, die den neuromuskulären Kontaktstellen im Skelettmuskel der Wirbeltiere ähnlich sind. Diese neuromuskulären Verbindungen verteilen sich über die Gesamtlänge des Schwanzes und sind offenbar die Innervation der Schwanzmuskulatur.

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Supported by grants No. NS-07495 and No. NS-07197 from the NIH, U.S. Public Health Service.