Effects of the Non-protein Amino Acids L-Canavanine and L-Canaline on the Nervous System of the Moth Manduca Sexta (L.)

1978 ◽  
Vol 75 (1) ◽  
pp. 123-132
Author(s):  
ANN E. KAMMER ◽  
D. L. DAHLMAN ◽  
GERALD A. ROSENTHAL

Injection of L-canavanine, a naturally occurring arginine analogue, and of its metabolic derivative, L-canaline, induced almost continuous motor activity in adult tobacco hornworms, Manduca sexta (L.). Initially the moths flew normally, but after a time interval that depended both on the amino acid and on the dose (1-l45/μmol/g fresh weight) the moths became disorientated and muscle activity was less patterned. Canaline produced its initial effects 12-30 min after injection, whereas activity in response to canavanine began after a delay of 1-2 h. Canaline (derived from canavanine by an arginase-mediated hydrolytic cleavage) is probably the biologically active factor. Canaline did not affect axonal conduction of action potentials nor the activity of mechanoreceptors on the forewing. Canaline (22μmol/g fresh weight) prolonged the postsynaptic potential of flight muscle fibres, but after 20-40 min. the electrical activity of muscle fibres was normal. The results show that canaline alters the activity of the central nervous system of adult M. sexta, but its mode of action is unknown.

1963 ◽  
Vol 44 (3) ◽  
pp. 475-480 ◽  
Author(s):  
R. Grinberg

ABSTRACT Radiologically thyroidectomized female Swiss mice were injected intraperitoneally with 131I-labeled thyroxine (T4*), and were studied at time intervals of 30 minutes and 4, 28, 48 and 72 hours after injection, 10 mice for each time interval. The organs of the central nervous system and the pituitary glands were chromatographed, and likewise serum from the same animal. The chromatographic studies revealed a compound with the same mobility as 131I-labeled triiodothyronine in the organs of the CNS and in the pituitary gland, but this compound was not present in the serum. In most of the chromatographic studies, the peaks for I, T4 and T3 coincided with those for the standards. In several instances, however, such an exact coincidence was lacking. A tentative explanation for the presence of T3* in the pituitary gland following the injection of T4* is a deiodinating system in the pituitary gland or else the capacity of the pituitary gland to concentrate T3* formed in other organs. The presence of T3* is apparently a characteristic of most of the CNS (brain, midbrain, medulla and spinal cord); but in the case of the optic nerve, the compound is not present under the conditions of this study.


In the study of the phenomena of anaphylaxis there are certain points on which some measure of agreement seems to have been attained. In the case of anaphylaxis to soluble proteins, with which alone we are directly concerned in this paper, the majority of investigators probably accept the view that the condition is due to the formation of an antibody of the precipitin type. Concerning the method, however, by which the presence of this antibody causes the specific sensitiveness, the means by which its interaction with the antibody produces the anaphylactic shock, there is a wide divergence of conception. Two main currents of speculation can be discerned. One view, historically rather the earlier, and first put forward by Besredka (1) attributes the anaphylactic condition to the location of the antibody in the body cells. There is not complete unanimity among adherents of this view as to the nature of the antibody concerned, or as to the class of cells containing it which are primarily affected in the anaphylactic shock. Besredka (2) himself has apparently not accepted the identification of the anaphylactic antibody with a precipitin, but regards it as belonging to a special class (sensibilisine). He also regards the cells of the central nervous system as those primarily involved in the anaphylactic shock in the guinea-pig. Others, including one of us (3), have found no adequate reason for rejecting the strong evidence in favour of the precipitin nature of the anaphylactic antibody, produced by Doerr and Russ (4), Weil (5), and others, and have accepted and confirmed the description of the rapid anaphylactic death in the guinea-pig as due to a direct stimulation of the plain-muscle fibres surrounding the bronchioles, causing valve-like obstruction of the lumen, and leading to asphyxia, with the characteristic fixed distension of the lungs, as first described by Auer and Lewis (6), and almost simultaneously by Biedl and Kraus (7). But the fundamental conception of anaphylaxis as due to cellular location of an antibody, and of the reaction as due to the union of antigen and antibody taking place in the protoplasm, is common to a number of workers who thus differ on details.


1989 ◽  
Vol 147 (1) ◽  
pp. 457-470 ◽  
Author(s):  
JAMES W. TRUMAN ◽  
PHILIP F. COPENHAVER

Larval and pupal ecdyses of the moth Manduca sexta are triggered by eclosion hormone (EH) released from the ventral nervous system. The major store of EH activity in the latter resides in the proctodeal nerves that extend along the larval hindgut. At pupal ecdysis, the proctodeal nerves show a 90% depletion of stored activity, suggesting that they are the major release site for the circulating EH that causes ecdysis. Surgical experiments involving the transection of the nerve cord or removal of parts of the brain showed that the proctodeal nerve activity originates from the brain. Retrograde and anterograde cobalt fills and immunocytochemistry using antibodies against EH revealed two pairs of neurons that reside in the ventromedial region of the brain and whose axons travel ipsilaterally along the length of the central nervous system (CNS) and project into the proctodeal nerve, where they show varicose release sites. These neurons constitute a novel neuroendocrine pathway in insects which appears to be dedicated solely to the release of EH.


1995 ◽  
Vol 198 (6) ◽  
pp. 1307-1311
Author(s):  
J J Milde ◽  
R Ziegler ◽  
M Wallstein

A simple preparation designed to screen and compare the central action of putative neuroactive agents in the moth Manduca sexta is described. This approach combines microinjections into the central nervous system with myograms recorded from a pair of spontaneously active mesothoracic muscles. Pressure injection of either octopamine or Manduca adipokinetic hormone (M-AKH) into the mesothoracic neuropile increases the monitored motor activity. Under the conditions used, the excitatory effects of M-AKH exceed those of the potent neuromodulator octopamine. This suggests that M-AKH plays a role in the central nervous system in addition to its known metabolic functions and supports recent evidence that neuropeptides in insects can be multifunctional.


2002 ◽  
Vol 76 (23) ◽  
pp. 12223-12232 ◽  
Author(s):  
Susanna Freude ◽  
Jürgen Hausmann ◽  
Markus Hofer ◽  
Ngan Pham-Mitchell ◽  
Iain L. Campbell ◽  
...  

ABSTRACT Targeted expression of biologically active interleukin-12 (IL-12) in astrocytes of the central nervous system (CNS) results in spontaneous neuroimmunological disease of aged mice. Borna disease virus (BDV) can readily multiply in the mouse CNS but does not trigger disease in most strains. Here we show that a large percentage of IL-12 transgenic mice developed severe ataxia within 5 to 10 weeks after infection with BDV. By contrast, no disease developed in mock-infected IL-12 transgenic and wild-type mice until 4 months of age. Neurological symptoms were rare in infected wild-type animals, and if they occurred, these were milder and appeared later. Histological analyses showed that the cerebellum of infected IL-12 transgenic mice, which is the brain region with strongest transgene expression, contained large numbers of CD4+ and CD8+ T cells as well as lower numbers of B cells, whereas other parts of the CNS showed only mild infiltration by lymphocytes. The cerebellum of diseased mice further showed severe astrogliosis, calcifications and signs of neurodegeneration. BDV antigen and nucleic acids were present in lower amounts in the inflamed cerebellum of infected transgenic mice than in the noninflamed cerebellum of infected wild-type littermates, suggesting that IL-12 or IL-12-induced cytokines exhibited antiviral activity. We propose that BDV infection accelerates the frequency by which immune cells such as lymphocytes and NK cells enter the CNS and then respond to IL-12 present in the local milieu causing disease. Our results illustrate that infection of the CNS with a virus that is benign in certain hosts can be harmful in such normally disease-resistant hosts if the tissue is unfavorably preconditioned by proinflammatory cytokines.


1956 ◽  
Vol s3-97 (38) ◽  
pp. 215-233
Author(s):  
L. H. FINLAYSON

Certain segmental units of the three main longitudinal muscle-bands in the abdomen of the larva of Galleria, Platysamia, Telea, Antheraea, and Samia (Philosamia) do not degenerate during the histolytic phase in the prepupa and early pupa. In the 3rd abdominal segment the amount of muscle that persists is variable; in the 4th, 5th, and 6th segments, invariable. Apart from single pairs of transverse muscles in the 2nd and 3rd segments and those of the gut and heart there are no other muscles in the pupa. Vestiges of degenerated muscles are often found in the pupa. The longitudinal muscles which survive the transformation of the pupa into the adult degenerate during the first 2 days of adult life. Experiments were made on larvae, prepupae, pupae, and adults in attempts to influence muscle-degeneration and muscle-persistence. Extirpation of ganglia or severance of nerves in larvae and prepupae of Galleria caused the normally persistent muscles to degenerate during pupation. Controls in which larvae were dissected before pupation revealed no degeneration of denervated muscles. In saturniids denervation also resulted in degeneration or atrophy but only after a much longer period, a matter of several weeks instead of several days. Muscles may be affected by extirpation of ganglia or severance of nerves in segments preceding their own segment. Previous workers have shown that the growth of the new adult muscles is dependent on the influence of the central nervous system. This is not so in the case of sheets of fine muscle-fibres lying under the epidermis of the adult. They develop in the absence of central innervation. Operations which had no effect on muscle-degeneration in the adult included extirpation of ganglia in pupa and adult, beheading and bleeding, extirpation of corpora allata plus corpora cardiaca, ligations, extirpation of pupal gonads, and isolation of adult abdomens. Substitution of blood from diapausing pupae or saline for the adult blood in isolated abdomens was effective in slowing the process of muscle-degeneration. This result shows that the blood composition is of importance in the process of histolysis in the adult. The previous work on the physiology of insect histolysis is briefly reviewed. The influence of the nervous system as described in this paper is discussed and related to similar findings in other arthropods and in vertebrates.


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