THE ANTAGONISM BETWEEN THYROID AND PARATHYROID GLANDS

From the facts stated in this paper it is evident that the thymus gland of mammals contains a substance which is capable of producing tetany when fed to the larvæ of certain species of salamanders (Ambystoma opacum and Ambystoma maculatum). As long as the larvæ have not developed their own thymus glands, they are able, by means of some mechanism, to counterbalance the tetanic action of the thymus substance introduced in their food. When, however, the secretion from their own thymus glands is added to the thymus material introduced with the food, this mechanism of preventing tetany becomes inadequate and tetany ensues. In the larva of a third species of salamander, Ambystoma tigrinum, this mechanism will prevent tetany even when the larvæ are fed on thymus. In mammals the parathyroids are known to prevent tetany and are supposed either to absorb the tetany-producing substance and thus prevent its action or to change it into another non-toxic substance. It is at least probable that in the amphibians the parathyroids play the same rôle. Larvæ of anuran amphibians, which develop their parathyroids soon after hatching, never show tetanic convulsions if they are fed on thymus, but in certain species of salamanders, whose parathyroids develop only during metamorphosis, the larvæ invariably have tetanic convulsions upon thymus feeding, while the metamorphosed animals never show tetany. But in addition to the parathyroids the salamanders must possess still another mechanism which during the larval period inhibits the production of tetany by the animal''s own thymus glands. In the larvæ of Ambystoma opacum and Ambystoma maculatum this mechanism is sufficient only to prevent tetany from the animal''s own thymus, while in the larvæ of Ambystoma tigrinum it is capable of preventing tetany even when the larvæ are fed with thymus. If the thymus is the organ by whose action tetany is produced, we can understand why tetany in human beings occurs far more frequently in children than in adults, since in the latter the thymus gland is replaced, at least to a great extent, by connective tissue. The relation of thymus to tetany may also possibly explain the occurrence of tetany during pregnancy; while the parathyroids of the mother may be sufficient to prevent tetany from her largely atrophied thymus, they may not be sufficient to prevent tetany from the excess of thymus substance furnished by the fetus to the blood of the mother.     

Verapamil and zero Ca2+ alter responses of cat muscle to halothane and caffeine

Strips of soleus (slow twitch, oxidative) and gracilis (fast-twitch, glycolytic) muscle were obtained from 27 anesthetized cats and mounted in organ baths filled with oxygenated Krebs-Ringer solution (37 degrees C). The responses to caffeine, halothane (1%), caffeine in the presence of halothane, and electrical stimulation in the presence of halothane were examined in the two fiber types. These responses were compared with those observed in paired strips of muscle that had been treated with verapamil (10 or 28 microM), a slow calcium (Ca2+) channel blocker, with zero Ca2+, or with zero Ca2+ where magnesium (3.7 mM Ca2+) was added to replace the Ca2+. Halothane-induced contractures in the soleus were blocked by verapamil and zero Ca2+. Caffeine-induced contractures and tetanic contractions were attenuated in zero Ca2+ and by verapamil in both fiber types. Halothane overcame verapamil-induced reductions of caffeine contractures and tetanic contractions in both fiber types. In contrast, halothane did not overcome zero Ca2+-induced reductions in caffeine contractures or tetanic contractions in either fiber type. Furthermore, the addition of Mg2+ to the zero Ca2+ did not restore the responses. The findings with verapamil indicate that in cat muscle, both halothane- and caffeine-induced contractures and tetanic contractions are dependent on the influx of extracellular Ca2+. This extracellular Ca2+ may enter through the slow Ca2+ channels. However, because halothane in combination with caffeine or electrical stimulation overcame the effects of verapamil, there may be other sites involved.     

The Neurological and Developmental Effects of Neonatal Hypoglycemia: A Follow-up of 22 Cases

Twenty-two infants in whom hypoglycemia (blood sugar less than 20 mg./100 ml.) was noted during the first few days of life were followed up when eight to 30 months of age. In eight such symptoms as muscular tremors, cyanosis, apneic spells and convulsions were associated with the hypoglycemia; five of these had abnormal central nervous system signs and retarded development. One other had possible impairment of development and another had a recurrence of hypoglycemia after having been well for four years. Fourteen of the 22 infants had no symptoms associated with the hypoglycemia, and on follow-up only two of these showed possible impairment. The rest were normal.This preliminary study suggests that hypoglycemia associated with neurological symptoms in the newborn period carries a poor prognosis with respect to permanent neurological damage. Asymptomatic hypoglycemia may have a relatively good prognosis.     

The structure of the tetanus toxin reveals pH‐mediated domain dynamics

The tetanus neurotoxin (TeNT) is a highly potent toxin produced by Clostridium tetani that inhibits neurotransmission of inhibitory interneurons, causing spastic paralysis in the tetanus disease. TeNT differs from the other clostridial neurotoxins by its unique ability to target the central nervous system by retrograde axonal transport. The crystal structure of the tetanus toxin reveals a “closed” domain arrangement stabilised by two disulphide bridges, and the molecular details of the toxin's interaction with its polysaccharide receptor. An integrative analysis combining X‐ray crystallography, solution scattering and single particle electron cryo‐microscopy reveals pH‐mediated domain rearrangements that may give TeNT the ability to adapt to the multiple environments encountered during intoxication, and facilitate binding to distinct receptors.     

In vitro lethal efficacy of leaf extract of Cannabis sativa Linn on the larvae of Chironomous samoensis Edward: an insect of public health concern

Leaf extract of C. sativa causes paralysis leading to death in larvae of C. samoensis. The extract brought a drastic change in the morphology of sensilla trichoidea and the general body cuticle. The larvae exposed to the leaf extract also showed a significant reduction in the concentration of Mg and Fe, while Mn showed only slight average increase. Since the sensilla trichoidea has nerve connection, it is expected that the toxic principle of the leaf extract has affected the central nervous system. The significant reduction of the level of Fe indicates that the extract could cause the reduction in oxygen binding capacity of the haemolymph, thereby acting as a respiratory poison in addition to its known role as a neurotoxic substance.     

RELATION BETWEEN THYROID GLAND,METAMORPHOSIS, AND GROWTH

1. Two substances are involved in amphibian metamorphosis as studied in Ambystoma opacum: first, iodine, which is taken up by the food, and second, an excretor substance, which is evolved during the processes of growth and serves to induce the excretory function of the thyroid gland. 2. This explains why in larvæ, whose metamorphosis is inhibited by lack of iodine, growth is checked at the time when metamorphosis should occur; for at this time the excretor substance commences to act and this results, if iodine is absent, in the excretion by the thyroid of toxic substances which cause the breakdown of proteins and consequently a decrease in size of the larvæ. 3. Larvæ whose metamorphosis is inhibited by extirpation of the thyroid or by the hereditary lack of a thyroid (as is the case in Typhlomolge) can grow normally, since in them the action of the excretor substance cannot result in the excretion by the thyroid of a toxic growth-inhibiting substance. 4. At low temperature less excretor substance is produced than at high temperature during an equal rate of growth; therefore larvæ kept at low temperature reach a larger size than larvæ kept at high temperature, before they metamorphose.     

The effect of muscle fatigue on the isometric contractile characteristics of skeletal muscle in the cat

The rise time of an isometric twitch, the tetanic tension, the twitch tetanus ratio, the frequency-tension relationship, and the height of the MUAP (motor unit action potential) were measured in fast twitch (medial gastrocnemius) and slow twitch (soleus) muscles of the cat immediately before, in the middle, and immediately after fatiguing isometric contractions at tensions of 30, 50 and 80% of each muscle's initial strength (tetanic tension recorded from the unfatigued muscle). Although the twitch-tetanus ratio was always less for the soleus than for the medial gastrocnemius muscles, the twitch-tetanus ratio for any one muscle was constant throughout the duration of fatiguing isometric contractions at any of the tensions examined. In contrast, the twitch tension and tetanic tension of the muscles were both less after the contractions, the largest reduction occurring for both muscles during contractions sustained at the lowest isometric tensions. The time to peak tension of an isometric twitch was prolonged for both muscles following the contractions. This was associated with a corresponding shift in the frequency tension relationship such that at the point of muscular fatigue, the muscles tetanized at lower frequencies of stimulation than did the unfatigued muscle. In contrast, the amplitude of the MUAP showed only a modest reduction throughout the duration of the fatiguing contractions.     

TISSUE DISTRIBUTION AND METABOLISM OF THE LATHYRUS SATIVUS NEUROTOXIN, L-3-OXALYLAMINO-2-AMINOPROPIONIC ACID, IN THE SQUIRREL MONKEY

Abstract– Although the L. sativus neurotoxin, L-3-oxalylamino-2-aminopropionic acid, is believed to cause neurological disease in humans, evidence that the toxin can enter the central nervous system except in animals with an immature or damaged blood-brain barrier is lacking. Experiments described here suggest that an intraperitoneal dose of L-3-[¹⁴C-oxalyl]amino-2-aminopropionic acid enters the central nervous system of young squirrel monkeys ( Saimiri sciureus ) whose blood-brain barrier is mature. Most of the radioactivity recovered from monkey urine and tissues 1 h after injection was unchanged toxin. None was recovered in expired air as radioactive carbon dioxide.     

Calcium metabolism and mineralocorticoid-induced hypertension: effects of parathormone and exogenous thyrocalcitonin and of variations in dietary calcium and magnesium]

Physiological doses of parathyroid extract producing normal serum calcium level restore mineralocorticoid hypertension development in parathyroidectomized or thyroparathyroidectomized rats, supplemented with thyroid hormones. On the other hand, increased calcium or magnesium in dietary moderates hypertension development. Those results confirm the participation of parathyroids during mineralocorticoid hypertension.     

NATURE OF THE RETARDING INFLUENCE OF THE THYMUS UPON AMPHIBIAN METAMORPHOSIS

1. Though thymus-fed salamander larvæ often metamorphose normally, thymus feeding sometimes retards and in rare cases inhibits metamorphosis completely. 2. The addition of normal food to a thymus diet abolishes the inhibitory effect of the thymus. 3. Addition of a small quantity of iodothyrin leads rapidly to precocious metamorphosis of thymus-fed larvæ. 4. The inhibitory effect of the thymus is not due to a specific inhibiting substance in the thymus, but to the absence from the thymus of a substance required to develop the thyroid to the secretory state.     

Calcium ion-stimulated phosphorylation of myelin proteins.

Myelin isolated from the central and peripheral nervous system contains a Mg2+-dependent protein kinase that catalyses phosphorylation of myelin-specific proteins. This phosphorylation is markedly stimulated by Ca2+ but not by cyclic AMP. Evidence was obtained that suggested an involvement of calmodulin-like protein in the stimulatory effects of Ca2+ on myelin phosphorylation.     

Mesenchymal Stem Cell Therapy Following Muscle Trauma Leads to Improved Muscular Regeneration in Both Male and Female Rats

BackgroundMesenchymal stem cell (MSC) therapy has the potential to enhance muscular regeneration. In previous publications, our group was able to show a dose-response relationship in female animals between the amount of transplanted cells and muscle force. The impact of sex on the regeneration of musculoskeletal injuries following MSC transplantation remains unclear.ObjectiveWe investigated histologic and biomechanical regeneration parameters in rats after autologous transplantation of MSCs. Our hypothesis was that female rats have greater muscle regeneration potential than male rats after autologous MSC transplantation.MethodsThirty-six Sprague-Dawley rats received an open crush trauma of the left soleus muscle. One week after trauma, 2.5 × 10⁶ autologous MSCs, harvested from tibial biopsies, were transplanted locally (female, n = 9; male, n = 9). Control animals received saline solution (female, n = 9; male, n = 9). Histologic analysis and biomechanical evaluation by in vivo muscle force measurement were performed 3 weeks after transplantation.ResultsMSC therapy improved the force of the injured soleus in male rats significantly (twitch: treated, 0.76 [0.51–1.15]; twitch: untreated, 0.45 [0.32–0.73] [P = 0.01]; tetany: treated, 0.63 [0.4–1.21], tetany: untreated, 0.34 [0.16–0.48] [P = 0.04]). Force measurements in females also revealed significant improvements (twitch: treated, 0.71 [0.38–0.96]; twitch: untreated, 0.36 [0.18–0.63] [P = 0.005]; tetany: treated, 0.53 [0.21–0.68]; tetany: untreated, 0.27 [0.11–0.47] [P = 0.01]). The intersexual comparison of fast twitch and tetanic contraction forces revealed no significance (twitch, P = 0.55; tetany, P = 0.19). The histologic analysis showed no differences in the amount of fibrotic tissue (male, P = 0.9; female, P = 0.14) and the size of muscle area (male, P = 0.2; female, P = 0.56) following treatment. Male animals showed higher values for muscle area (P = 0.011) and less fibrosis (P = 0.028), independent of treatment.ConclusionThe outcome of skeletal muscle regeneration after injury can be improved in animals of both sexes with MSC transplantation.     

Influence of calcium and magnesium deprivation on ovulation and ovum maturation in the perfused rabbit ovary

The role of calcium (Ca++) and magnesium (Mg++) in the ovulation process was studied using in vitro perfused rabbit ovaries. Ovaries were perfused with or without human chorionic gonadotropin (hCG) in Ca++/Mg++-free medium (M199) alone or combined with standard M199 to yield varying concentrations of Ca++ and/or Mg++. In all ovaries perfused with hCG, ovulatory efficiency was similar regardless of the concentration of Ca++ and/or Mg++. In ovaries perfused in Ca++/Mg++-free medium without hCG, ovulatory efficiency was similar to that in ovaries perfused with hCG. As Ca++/Mg++ levels were increased without hCG, ovulatory efficiency declined. Ovulation time was significantly accelerated in ovaries perfused in Ca++/Mg++-free medium with or without hCG. Most ovulated ova from ovaries perfused without hCG were immature. With hCG, degree of ovum maturity was directly related to ovulation time. Ovarian smooth muscle contractions were undetectable in 3 ovaries perfused in Ca++/Mg++-free M199 despite occurrence of ovulation. Smooth muscle contractions were recorded in 2 of 3 ovaries perfused in standard M199 with hCG. These results indicate: 1) Ca++/Mg++ exclusion results in rapid follicle rupture and immature ova; 2) oocyte maturation appears to be gonadotropin-dependent; 3) ovulation occurs in the absence of ovarian smooth muscle contractions during perfusion with Ca++/Mg++-free medium.     

Effects of systemic arterial blood pressure on the contractile force of a human hand muscle.

The effect of physiological changes in systemic blood pressure on the force output of working abductor pollicis (AP) muscle was studied in six normal subjects. Supramaximal tetanic stimulation at the ulnar nerve produced repeated isometric contractions at 1-s intervals. Force output declined gradually with time. During the train of contractions, subjects voluntarily contracted the knee extensors for 1 min; this raised systemic blood pressure by 29%. Force output from AP rose in parallel with blood pressure so that 18% of the contraction force lost through fatigue was recovered for each 10% increase in blood pressure. When blood pressure in the hand was kept constant despite the increased systemic pressure, force output did not rise. The results show that muscle performance is strongly affected by physiological changes in central blood pressure and suggest that sensory input concerning the adequacy of muscle performance exerts a feedback control over the increase in systemic blood pressure during muscular activity.     

Effect of N,K, and P fertilization,N source,and clipping on potential tetany hazard of bromegrass

Summary The objective of this field study was to determine early-season effects of N source, N, K, and P fertilization, and clipping (to simulate grazing) on potential tetany hazard of bromegrass (Bromus inermis L.) as indicated by the chemical composition of its forage. Tetany is a metabolic disorder of ruminants resulting from forage with low Mg availability. Chemical components considered in the forage were inorganic cations, organic acids, aconitate, and per cent total N/per cent total water soluble carbohydrate (N/TWSC). Differences between the sum (in meq/kg) of inorganic cations (Mg, Ca, K, and Na) and inorganic anions (Cl, NO₃, H₂PO₄, and SO₄) in forage were defined as the concentration of organic acids (C-A). Soil was Parshall fsl, a Pachic Haploboroll. Yields and chemical composition of oven-dried forage from previously unclipped and reclipped plots were determined at 3-week intervals beginning May 22 and June 12, respectively. A water budget was determined using soil-water and rainfall data.Forage yields were increased 2- to 3-fold by N fertilization with the NO₃-N source generally outyielding the NH₄-N source. A slight additional yield response to that obtained with N alone was obtained with K+P fertilization but not with K or P alone with or without N. Much less total forage was removed from reclipped plots than from unclipped plots. Forage Mg content was decreased only slightly by K or NH₄-N fertilization. Soil analysis indicated that high NH₄-N levels were present at the May 22 harvest. Magnesium and Ca concentrations were only slightly affected by N fertilization; however, K, K/(Ca+Mg), total N, C-A, and aconitate were increased. Reclipping increased Mg, N, K, N/TWSC, C-A, and aconitate. Estimates of blood-plasma Mg concentrations were obtained by using the data for plant N, K, and Mg. These estimates did not indicate increased tetany hazard as a result of reclipping, but did indicate increased tetany hazard from N fertilization. Forage C-A and aconitate concentrations were decreased by fertilization with KCl which seemed to have been caused by the increased Cl concentrations in the forage. Estimates of quantities of Mg, arriving at the root surfaces from the soil by mass flow, far exceeded amounts of Mg in the forage. Mass flow seemed to be the principal mechanism by which Mg and Ca arrived at root surfaces but this mechanism was much less important for K.This study indicated an increased potential tetany hazard resulting primarily from N fertilization with either NH₄-N or NO₃-N sources. However, the potential for increased forage and livestock-carrying capacity with N fertilization is very large. Therefore, management practices corroborated by livestock data are vitally needed to minimize tetany hazard while increasing bromegrass yields by N fertilization.Contribution from Soil, Water, and Air Sciences, North Central and Northeastern Regions, ARS-USDA.Follett, Power, and Grunes are soil scientists and Kleinis a biological laboratory technician. Follett is now National Program Staff Scientist, ARS, BARC-West, Beltsville, MD 20705. Power and Klein are at the USDA Northern Great Plains Research Center, Mandan, ND 58554, as formerly was Follett. Grunes is at the U.S. Plant, Soil and Nutrition Laboratory, Ithaca, NY 14853.     

Cross-protection against challenge by intravenous Escherichia coli verocytotoxin 1 (VT1) in rabbits immunized with VT2 toxoid

Rabbits challenged intravenously with Escherichia coli verocytotoxin (VT1, Shiga toxin 1, Stx1) die after developing diarrhea and paralysis, and this outcome can be prevented by pre-immunization with VT1 toxoid. In nonimmune rabbits, intravenously administered 125I-VT1 binds to the central nervous system and gastrointestinal tract, whereas in immunized animals, these organs are spared and the toxin localizes in the liver and spleen. In rabbits immunized with either VT1 or VT2 toxoids, both the homologous or heterologous toxins are prevented from binding to target organs. This has lead to the advancement of a hypothesis that cross-protection in vivo can be induced to both toxins by immunization with a toxoid even though these toxins do not exhibit cross-neutralization in vitro. It was shown that rabbits immunized with VT2 were fully protected from the intravenous administration of 10 LD50 and 50 LD50 of VT1, and this correlated directly with the protection from binding of this toxin to target organs. These findings have important implications on the design of the vaccination strategies to prevent human VT-mediated diseases and also validate the concept of testing for immunity to VT by monitoring the inhibition of binding of the 125I-VT to target organs in preference to performing LD50 assays.     

Parathyroid Glands of Amphibians. I. Parathyroid Structure and Function in the Amphibian, with Emphasis on Regulation of Mineral Ions in Body Fluids

Parathyroid glands of amphibians develop from the pharyngealpouches and are located adjacent to the external jugular veinand hypoglossal nerve. They are composed of whorls of compactepithelial cells covered by a vascular capsule of connectivetissue. Possibly two cell types are present: (a) peripheralclear cells, which are implicated in elaboration of hormoneand contain secretory granules, and (b) dense reserve cells.During winter, the parathyroids undergo degeneration, characterizedby morphological details which vary with the species; this isfollowed by regeneration in the spring. Parathyroidectomy maycause hyperexcitability, but rarely does tetanic death occur.Parathyroidectomized amphibians, like mammals, become hypocalcemicand hyperphosphatemic. In contrast to higher vertebrates, however,parathyroprivic anurans show an elevated urine phosphorus, whichis presently interpreted as a reflection of the increased plasmaload due to absence of a hormonally-induced, soft-tissue accumulationof phosphate. Further, parathyroidectomized frogs are hypercalciuric,possibly because of the lack of hormone-mediated mesonephricreabsorption. In both mammals and amphibians, treatment withexogenous parathormone induces hypercalcemia, hypercalciuria,and hypophosphatemia. The absence of change in the urine phosphoruscontent of hormone-treated frogs, associated with its declinein plasma, may be a consequence of metabolic variations basedupon the heterothermic nature of the Amphibia.     

Activity- and Ca(2+)-dependent modulation of surface expression of brain-derived neurotrophic factor receptors in hippocampal neurons

Brain-derived neurotrophic factor (BDNF) has been shown to regulate neuronal survival and synaptic plasticity in the central nervous system (CNS) in an activity-dependent manner, but the underlying mechanisms remain unclear. Here we report that the number of BDNF receptor TrkB on the surface of hippocampal neurons can be enhanced by high frequency neuronal activity and synaptic transmission, and this effect is mediated by Ca(2+) influx. Using membrane protein biotinylation as well as receptor binding assays, we show that field electric stimulation increased the number of TrkB on the surface of cultured hippocampal neurons. Immunofluorescence staining suggests that the electric stimulation facilitated the movement of TrkB from intracellular pool to the cell surface, particularly on neuronal processes. The number of surface TrkB was regulated only by high frequency tetanic stimulation, but not by low frequency stimulation. The activity dependent modulation appears to require Ca(2+) influx, since treatment of the neurons with blockers of voltage-gated Ca(2+) channels or NMDA receptors, or removal of extracellular Ca(2+), severely attenuated the effect of electric stimulation. Moreover, inhibition of Ca(2+)/calmodulin-dependent kinase II (CaMKII) significantly reduced the effectiveness of the tetanic stimulation. These findings may help us to understand the role of neuronal activity in neurotrophin function and the mechanism for receptor tyrosine kinase signaling.     

Benzodiazepine inverse agonist, DMCM- and peripheral agonist, Ro 5-4864-induced convulsions in mice: effect of adenosinergic agents

Adenosinergic agents such as adenosine, 2-chloro-adenosine, N6-cyclohexyladenosine produced dose-dependent protective effect against DMCM- and Ro 5-4864-induced convulsions and mortality. N6-cyclohexyladenosine produced most significant protective e ect against Ro 5-4864-induced convulsions whereas 2-chloroadenosine was more effective than N6-cyclohexyladenosine in antagonising DMCM-induced convulsions. Pretreatment of animals with subprotective doses of adenosine and dipyridamole significantly prolonged the latencies for the onset of myoclonic jerks and convulsions due to both DMCM and Ro 5-4864. DMCM and Ro 5-4864-induced mortality rate was also significantly reduced by pretreatment with subprotective doses of adenosine and dipyridamole. Similarly, subprotective doses of adenosine and diazepam further delayed the latencies for myoclonic jerks and convulsions due to DMCM and Ro 5-4864 treatment. The results suggest that adenosine and adenosine receptor agonists, 2-chloroadenosine and N6-cyclohexyladenosine are protective against both DMCM- and Ro 5-4864-induced convulsions. It is suggested that adenosinergic agents via activation of central A1 adenosine receptors may modulate the convulsant effects mediated by DMCM and Ro 5-4864. This study further supports the notion that adenosinergic mechanisms mediate neuroprotective e ects in the central nervous system.     

Myelin Oligodendrocyte Glycoprotein (MOG35-55) Induced Experimental Autoimmune Encephalomyelitis (EAE) in C57BL/6 Mice

Multiple sclerosis is a chronic neuroinflammatory demyelinating disorder of the central nervous system with a strong neurodegenerative component. While the exact etiology of the disease is yet unclear, autoreactive T lymphocytes are thought to play a central role in its pathophysiology. MS therapy is only partially effective so far and research efforts continue to expand our knowledge on the pathophysiology of the disease and to develop novel treatment strategies. Experimental autoimmune encephalomyelitis (EAE) is the most common animal model for MS sharing many clinical and pathophysiological features. There is a broad diversity of EAE models which reflect different clinical, immunological and histological aspects of human MS. Actively-induced EAE in mice is the easiest inducible model with robust and replicable results. It is especially suited for investigating the effects of drugs or of particular genes by using transgenic mice challenged by autoimmune neuroinflammation. Therefore, mice are immunized with CNS homogenates or peptides of myelin proteins. Due to the low immunogenic potential of these peptides, strong adjuvants are used. EAE susceptibility and phenotype depends on the chosen antigen and rodent strain. C57BL/6 mice are the commonly used strain for transgenic mouse construction and respond among others to myelin oligodendrocyte glycoprotein (MOG). The immunogenic epitope MOG_35-55 is suspended in complete Freund''s adjuvant (CFA) prior to immunization and pertussis toxin is applied on the day of immunization and two days later. Mice develop a "classic" self-limited monophasic EAE with ascending flaccid paralysis within 9-14 days after immunization. Mice are evaluated daily using a clinical scoring system for 25-50 days. Special considerations for care taking of animals with EAE as well as potential applications and limitations of this model are discussed.