Image analysis of FITC-immunofluorescence histochemistry in perivascular substance P-positive nerves

Summary The ability of image analysis to quantify nerves labelled by FITC-immunofluorescence histochemistry has been tested on whole-mount stretch preparations of perivascular substance P-positive nerves. It has been shown that image analysis can make consistent measurements of nerves demonstrated by immunohistochemistry despite the fading of FITC-fluorescence which occurs during storage and on exposure to ultraviolet light.     

Fine structure and axonal organization in the buccal ganglia nerves ofAplysia (Mollusca,Gastropoda)

Summary The morphology of theAplysia buccal nerves and connectives has been studied by electron microscopic analysis. In these nerves the fine structure of the elements (connective sheath, glia, axons and their vesicular and cytoplasmatic content) is similar to that of other molluscan nerves. Some features seem to be comparable to other invertebrate groups such as Crustacea and Annelida. The axons have been divided into four classes on the basis of their calibre, and each type has been counted in all the nerves. The number of axons relating to identified buccal neurons is discussed. Finally, some speculations about relationships between buccal ganglia and peripheral regions connected by buccal nerves are proposed.     

Developmental interactions between the peripheral and central nervous system in Drosophila melanogaster: analysis of the mutant, two-faced

A genetically complex mutant, two-faced (tfd), which causes the production of extra eye and antennal tissue on the dorsal head cuticle, has been analyzed for connectivity to and projection patterns in the central brain of nerves derived from these extra structures. It has been found that the extra antennal nerves frequently connect to and achieve normal projections in the brain, whereas no convincing connectivity between the nerves from the extra eye tissue and the brain, has been found. This suggests that the mechanisms by which the nerves derived from normal eyes and antennae achieve central connections may differ.     

Optical recording of action potential propagation in demyelinated frog nerve.

Conduction in focally demyelinated frog nerves has been measured optically using potential-sensitive dyes. Absorption changes were recorded with an array of photodiodes positioned in the image plane of a microscope. Both the amplitude and conduction velocity of the optical signals decreased in the demyelinated region. Conduction was improved after exposure to the potassium channel blocking agent 4-aminopyridine.     

Role of the vagus nerve in mechanisms of the modulation of afferent duodenal effects]

The electrostimulation of vagal nerves, the effect of naloxone and atropine on duodenal afferentation by registering evoked potential (EP) at cortex on direct electrostimulation of duodenum have been studied in acute experiments on cats. It has been established that the stimulation of afferent portion of vagal nerves causes the effect of deprivation of EP, whereas the stimulation with certain intensity of efferent portion of vagal nerves intensifies the duodenal afferentation. The effect of afferentation easeness (relief) has been blocked by the application of naloxone 10-20 microgram on duodenal bulbus, but not on it's i. v. injection and without effect on local application of atropine. It is concluded that the role of vagal nerves on the modulation of duodenal nociception is due to the activation of opiate terminals of the efferent vagal nerve portions.     

Capsaicin receptor expression in the rat temporomandibular joint

Experimentally, temporomandibular joint (TMJ) nerve units respond to capsaicin, which is used clinically to treat TMJ pain. However, the existence of capsaicin receptors in the TMJ has not previously been clearly demonstrated. Immunohistochemical analysis has revealed the presence of transient receptor potential vanilloid subtype 1 (TRPV1) expression in the nerves and synovial lining cells of the TMJ. TRPV1-immunoreactive nerves are distributed in the synovial membrane of the joint capsule and provide branches to the joint compartment. The disc periphery is supplied by TRPV1 nerves that are mostly associated with small arterioles, and occasional nerves penetrate to the synovial lining layer. Double immunofluorescence has shown that many TRPV1-immunoreactive nerves are labeled with neuropeptide calcitonin gene-related peptide, whereas few are labeled with IB4-lectin. The results provide evidence for the presence of TRPV1 in both nerves and synovial lining cells, which might thus be involved in the mechanism of nociception and inflammation in the TMJ. This study was supported by a grant-in-aid for Scientific Research (C), no. 15591938, from the Japanese Ministry of Education, Science, Sports, Culture, and Technology (to M.A.K.).     

Regeneration of peripheral nerves and intracerebral transplantation]

Axoplasmic flow is essential to the regeneration of peripheral nerves. We observed a mean of 12 mm/day for the slow axoplasmic flow and a mean of 410mm/day for the fast axoplasmic flow. In the process of regeneration of peripheral nerves, however, slow transport increased to 14.7mm/day and fast transport to 572mm/day on day 7. We reviewed the relevant literature on the axoplasmic flow and described the topics in this report. Some central nerves may show poor regeneration but it has been confirmed that nerve cells grow and survive by intracerebral nerve transplantation, and this technique has been applied to the treatment of Parkinson's disease. Further development can be expected for the regeneration of central nerves through transplantation.     

Influence of VIP on thyroid hormone secretion

Since VIP occurs in intrathyroidal nerves its role in thyroid hormone secretion has been investigated. It has been found that VIP is a stimulator of iodothyronine secretion in mice. In this respect VIP has a weaker potency than TSH, but shows a similar time characteristic. Also, VIP and TSH potentiate each others effects. In contrast to the effect of TSH, that of VIP is uninfluenced by alpha-adrenoceptor blockade. VIP, like TSH, stimulates thyroid cyclic AMP production. Thus, VIP nerves might, together with TSH, adrenergic and cholinergic nerves and other peptides such as somatostatin, participate in the complex regulation of iodothyronine secretion. Beside this, VIP has also been found to stimulate calcitonin secretion in rats. Other intrathyroidal neuropeptides, such as substance P and CCK-4, have been found to be without effects on iodothyronine secretion, but, like VIP, to stimulate calcitonin secretion.     

Innervation of the renal cortex.

Morphologic studies of renal innervation have utilized the methods of histochemistry and electron microscopy. Much information has been derived from examination of the renal cortex in monkey and rat. Fluorescence histochemistry shows a rich adrenergic innervation. Acetylcholinesterase can be demonstrated histochemically in the renal nerves by light and electron microscopy. Studies in the rat using 6-hydroxydopamine, a drug that selectively destroys adrenergic nerves, indicate that the glomerular arterioles and surrounding tubules are innervated by adrenergic nerves containing acetylcholinesterase. Distinct neurovascular and neurotubular junctions are observed the electron microscope. They are anatomically consistent with being the sites of synaptic transmission. Ultrastructural analysis of serial sections reveals that single individual axons contact multiple vascular cells and renal tubules. We now have a considerable body of information concerning the morphology of renal innervation are are beginning to appreciate the role of the renal nerves in kidney function.     

Neuromuscular blocking agents and spontaneous sympathetic activity.

The action of neuromuscular blocking agents on the spontaneous sympathetic activity has been quantitated. "On line" spectrum analysis has been applied to the action potential of pre- and post ganglionic nerves of the coeliac plexus. The activity, the frequency spectrum and their changes after the injection of clinical and high doses of decamethonium, D-tubocurarine, succinylcholine, gallamine and pancuronium are determined.     

Axoplasmic flow of adrenaline and monoamine oxidase in amphibian sympathetic nerves

Summary The accumulation of both A and MAO proximal to a ligature on toad spinal nerves has been shown to occur at a slower rate than in mammals. As in mammals, there are two components of axonal transport in amphibian nerves, with the accumulation of A reaching a peak at between 4 and 7 days (cf. 2–4 days for NA in mammals), while MAO accumulation does not reach its maximum before 9 days (cf. 7 days in mammals). No accumulation occurs after sympathectomy, providing evidence for localization of MAO within amphibian sympathetic adrenergic nerves. Distal accumulation of MAO occurs in toad sympathetic nerves; this has not been reported to occur in mammalian nerves. Distal accumulation reaches a peak at 2–4 days, which suggests either a fast retrograde flow of MAO or that induction of MAO is occurring. These results are discussed in relation to differences between mammalian and amphibian sympathetic nerves and to the events occurring following ligation of these nerves.We wish to thank Judy Lenk, Vivienne Einhorn and Barbara Peachey for their assistance with the initial MAO histochemical work. This work was supported by grants from the National Heart Foundation of Australia and the Australian Research Grants Committee.     

Regulation of motor activity of omasum after blockade of vagus nerves

In 3 sheep with subcutaneously exposed vagus nerves and with chronic large fistula of the rumen pharmacological analysis of the motor activity of omasum was carried out after blockade of vagus nerves. The contractions of omasal canal, reticulum and rumen were recorded by the baloon method. After blockade of the vagus nerves with anesthetics the proper pharmacological agents were administered in intravenous injections. In the light of the obtained results it was found that contractions of the omsal canal, persisting after vagal blockade, are independent of the influence of the autonomic system and they are probably due to myogenic automatism. It has been also demonstrated that both alpha and beta adrenergic receptors participate in regulation of the tonous of omasum musclular layers.     

Axoplasmic flow of adrenaline and monoamine oxidase in amphibian sympathetic nerves

Summary The accumulation of both A and MAO proximal to a ligature on toad spinal nerves has been shown to occur at a slower rate than in mammals. As in mammals, there are two components of axonal transport in amphibian nerves, with the accumulation of A reaching a peak at between 4 and 7 days (cf. 2–4 days for NA in mammals), while MAO accumulation does not reach its maximum before 9 days (cf. 7 days in mammals). No accumulation occurs after sympathectomy, providing evidence for localization of MAO within amphibian sympathetic adrenergic nerves. Distal accumulation of MAO occurs in toad sympathetic nerves; this has not been reported to occur in mammalian nerves. Distal accumulation reaches a peak at 2–4 days, which suggests either a fast retrograde flow of MAO or that induction of MAO is occurring. These results are discussed in relation to differences between mammalian and amphibian sympathetic nerves and to the events occurring following ligation of these nerves.We wish to thank Judy Lenk, Vivienne Einhorn and Barbara Peachey for their assistance with the initial MAO histochemical work. This work was supported by grants from the National Heart Foundation of Australia and the Australian Research Grants Committee.     

The peripheral nerves of non-diabetic rats after streptozotocin administration using automatic microscopic image analysis

Electrophysiologic studies of posterior tibial nerves by averaging method and morphometric investigations of sural nerves by automatic image analysis were performed in 7 non-diabetic rats 42 d after the administration of 55 mg streptozotocin/kg b.w. and in 10 untreated controls. Morphometry of stained semithin sections was carried out with system A 6471-AMBA/R (Robotron, Dresden, G.D.R.). There was no decrease of motor nerve conduction velocity in streptozotocin injected animals. The investigated morphometric parameters showed no significant alterations in the streptozotocin group. The studies show that in streptozotocin diabetic rats electrophysiological and morphological alterations of the peripheral nerve are caused by hyperglycemia but not by direct neurotoxic effects of streptozotocin.     

P0 and myelin basic protein-like immunoreactivities following ligation of the sciatic nerve in the rat

In this work we analyzed variations in the expression of MBPs and P₀ in ligated sciatic nerves of young and adult rats at 3, 7, and 14 days postligation (PL), by immunohistochemistry and SDS-PAGE of isolated myelin. A protein redistribution was seen in the distal stump of ligated nerves with the appearance of immunoreactive clusters. Using the KS400 image analyzer, immunostained area values were obtained from the different nerves dissected. In adult rats, there was an increase of the immunostained area for MBP from 3 to 7 days PL, coincident with a reorganization of the marker in clusters, followed by a marked decrease at 14 days. P₀ immunolabeling gave similar results without, however, a decrease of the immunostained area at the longer survival time tested. Young animals showed an acceleration in the process of protein redistribution and digestion within ligated nerves, which followed a similar pattern as that of adult animals. Analysis by electrophoresis showed a marked decrease in P₀ and MBP at 7 days PL in young rats and 14 days PL in adult rats. The functional significance of protein clustering within myelin in injured nerves deserves further analysis.     

Neural inhibition of egg-laying in the locust, Locusta migratoria

The role of the oviducal nerves during egg-laying in Locusta migratoria has been examined. Section of the oviducal nerves did not inhibit egg-laying in any observable way. Electrical stimulation of the oviducal nerves resulted in a contraction of the common and lower lateral oviducts which propelled ovulated eggs up towards the ovaries. Recordings from oviducal nerves using chronically implanted electrodes showed that electrical activity was low during actual egg-laying, but high at times when egg-laying was not occurring (i.e. during digging behaviour, or following interruption of egg-laying). During these periods of high activity recurrent bursts of action potentials occurred. Similar patterns of electrical activity were recorded in semi-intact preparations using suction electrodes applied to exposed oviducal nerves of locusts which had been interrupted during the process of egg-laying. High frequency bursts of activity were recorded simultaneously from both left and right oviducal nerves.It is concluded that one function of the oviducal nerves is to inhibit egg-laying at inappropriate times, by inducing contractions of the oviducts which propel eggs back towards the ovaries. These nerves therefore provide a physiological basis for part of the adaptive ovipositional activities of locusts.     

TRANSMITTER METABOLIZING ENZYMES AND FREE AMINO ACID LEVELS IN SENSORY AND MOTOR NERVES AND GANGLIA OF THE SHORE CRAB (CARCINUS MAENAS)

—The distribution of ChAT (choline acetyltransferase), GAD (glutamate decarboxylase) and acetylcholinesterase in some sensory and motor nerves of the shore crab, Carcinus maenas, has been investigated using micro-assay techniques. ChAT was concentrated in the afferent nerve fibres of the thoracic-coxal muscle receptor as well as in the coxo-basal chordotonal receptor nerve and other leg sensory fibres. GAD was found in leg motor nerves including the promotor and remotor muscle nerves, being undetectable in the sensory nerves. Acetylcholinesterase was found in similar levels in both sensory and motor nerves assayed. Amino acid analysis using a micro-dansylation technique showed that sensory nerves had low GABA levels, whereas the leg nerve including motor fibres had substantially higher GABA concentrations. GAD and GABA were also found in low amounts in the leg promoter mucle, which is consistent with GABA being a neuromuscular transmitter.     

Postoperative hypoparathyroidism: risk of complications]

For assessing the risk of adverse complications of surgery the group of 130 patients with post-operational hypoparathyroidism was analysed. Surgical hypoparathyroidism has been diagnosed in 51% of operated on thyroid gland patients. Laryngeal nerves have been damaged in 46.6% of patients. The injury to laryngeal nerves has been irreversible in 2/3 of patients, and reversible in the remaining 1/3. Cataract, nephrolithiasis and vitamin D3 intoxication have been observed in some cases before surgery. Their incidence increased in severe surgical hypoparathyroidism. Osteoporosis of the spine has been diagnosed in 49% of patients including some with vertebral fractures. No correlation between the degree of spine osteoporosis and diagnosis before surgery, number of operations on thyroid gland, and type of therapy has been noted. The symptoms of hypercalcemia have been diagnosed in 5 patients out of which hypercalcemia has been transient in 2 patients, and lasted for 1-5 months in the remaining 3 patients. The results of 7,873 analyses of mineral metabolism have been assessed. Hypocalcemia has been found in 38.4%, hypercalcemia in 1.6%, hypomagnesemia in 25.7%, hyperphosphatemia in 41.5%, decreased alkaline phosphatase serum activity in 28.7%, and hypercalciuria in 22.4% of cases. Surgical hypoparathyroidism is frequently accompanied by surgical hypothyroidism and injury to the recurrent laryngeal nerves.     

Protein Synthesis and Axonal Transport During Nerve Regeneration

Abstract— Protein synthesis and axonal transport have been studied in regenerating peripheral nerves. Sciatic nerves of bullfrogs were unilaterally crushed or cut. The animals were killed 1, 2, or 4 weeks later, and 8th and 9th dorsal root ganglia removed together with sciatic nerves and dorsal roots. The ganglia were selectively labeled in vitro with [³⁵S]-methionine. Labeled proteins, in dorsal root ganglia and rapidly transported to ligatures placed on the sciatic nerves and dorsal roots, were analyzed by two-dimensional polyacryl-amide gel electrophoresis. Qualitative analysis of protein patterns revealed no totally new proteins synthesized or rapidly transported in regenerating nerves. However, quantitative comparison of regenerating and contralateral control nerves revealed significant differences in abundance for some of the proteins synthesized in dorsal root ganglia, and for a few of the rapidly transported proteins. Quantitative analysis of rapidly transported proteins in both the peripheral processes (spinal nerves) and central processes (dorsal roots) revealed similar changes despite the fact that the roots were undamaged. The overall lack of drastic changes seen in protein synthesis and transport suggests that the neuron in its program of normal maintenance synthesizes and supplies most of the materials required for axon regrowth.     

A New Color Image Encryption Scheme Using CML and a Fractional-Order Chaotic System

The chaos-based image cryptosystems have been widely investigated in recent years to provide real-time encryption and transmission. In this paper, a novel color image encryption algorithm by using coupled-map lattices (CML) and a fractional-order chaotic system is proposed to enhance the security and robustness of the encryption algorithms with a permutation-diffusion structure. To make the encryption procedure more confusing and complex, an image division-shuffling process is put forward, where the plain-image is first divided into four sub-images, and then the position of the pixels in the whole image is shuffled. In order to generate initial conditions and parameters of two chaotic systems, a 280-bit long external secret key is employed. The key space analysis, various statistical analysis, information entropy analysis, differential analysis and key sensitivity analysis are introduced to test the security of the new image encryption algorithm. The cryptosystem speed is analyzed and tested as well. Experimental results confirm that, in comparison to other image encryption schemes, the new algorithm has higher security and is fast for practical image encryption. Moreover, an extensive tolerance analysis of some common image processing operations such as noise adding, cropping, JPEG compression, rotation, brightening and darkening, has been performed on the proposed image encryption technique. Corresponding results reveal that the proposed image encryption method has good robustness against some image processing operations and geometric attacks.