Convergent inputs from articular,cutaneous and muscle receptors onto ascending tract cells in the cat spinal cord

Summary 1.Responses were recorded from 160 ascending tract cells in segments L4 to L6 of the spinal cord in chloralose anaesthetized, spinalized cats. The tract cells were identified by antidromic activation following stimulation of pathways in the lateral and ventral funiculi at the level of the spinal cord transection at the thoracolumbar junction. Axonal conduction velocities ranged from 9 to 114 m/s. 2. A sample of 152 of the neurones examined could be subdivided according to the distribution of their receptive fields into 49 cells activated just from receptors located in skin (s cells), 17 neurones excited by receptors in deep tissues (d cells), 15 units with a convergent input from receptors in skin and deep tissues (sd cells), and 25 neurones with a convergent input from the knee joint and either skin (sj cells), deep tissues (dj cells) or both (sdj cells). No receptive fields could be demonstrated for the remaining 46 neurones. 3. S and sj cells were found almost exclusively in the dorsal horn, whereas many d, sd, sdj and dj units were in the ventral horn. Almost all of the cells that lacked receptive fields were in the ventral horn or intermediate grey. 4. Ninety-one of 158 cells (56%) demonstrated no background activity. Of these, 43 cells (27%) lacked receptive fields. Many of the silent neurones were in the ventral horn, but some were in the dorsal horn. Of 25 cells having knee joint input, 18 (72%) had background activity. 5. All of the neurones that had a receptive field in the knee joint also had a convergent input from receptors in other tissues. In 3 cases, there was a receptive field in the skin over the foot (sj cells). For 16 cells, receptive fields included not only the knee joint but also skin and deep tissue (sdj cells). Usually, the cutaneous receptive field was near the knee joint, but sometimes it was remote, such as on the foot. The deep receptive fields were chiefly in the muscles of the thigh and/or leg. For 6 dj cells, the receptive fields included not only the knee joint but also deep fields like those of sdj cells. 6. Cutaneous receptive fields were classified as low threshold (cells excited best by innocuous intensities of mechanical stimulation), wide dynamic range (cells activated by weak mechanical stimuli, but the best responses were to noxious stimuli) or high threshold (innocuous stimuli had little effect, but noxious mechanical stimuli produced a vigorous discharge). Similarly, stimulation of the knee joint with weak mechanical stimuli could excite some neurones, while others could be activated by weak or strong articular stimuli but were excited best by noxious stimuli, and still other neurones were activated by knee joint stimuli only if the intensity was noxious. 7. In several instances, contralateral receptive fields were noted. These were generally in deep tissue or in the knee joint. 8. It was concluded that many of the responses to articular stimulation of the spinal cord ascending tract cells examined in this study could have been mediated by the fine afferent fibres that supply the knee joint. Although further work will be required to determine which particular ascending tracts transmit nociceptive information concerning the knee joint, it can be proposed that many of the responses demonstrated here were likely to play a role in either joint pain of in triggering responses associated with joint pain.     

”Reflexes of purpose and freedom” in the comparative physiology of higher nervous activity

The most complex unconditioned reflexes of aim and freedom, discovered by I. P. Pavlov, are compared with the competence drive and the motivation of the resistance to coercion, respectively, described by contemporary ethologists. On the basis of the unconditioned reflex of purpose, conditioned reflexes were developed in which positive emotions arising in connection with the perfection of a skill, irrespective of its pragmatic significance at a given moment, serve as the reinforcement. The unconditioned reflex of freedom is regarded as a phylogenetic precursor of the will, and its acute extinction as the physiological mechanism of hypnosis. It was demonstrated experimentally that the appearance of the state of animal hypnosis (immobilization catatonia) in rabbits is accompanied by the predominance of electrical activity and heat production in the right hemisphere, i. e., by symptoms which are found in hypnosis in man.Translated from Zhurnal Vysshei Nervnoi Deyatel'nosti imeni I. P. Pavlova, Vol. 39, No. 3, pp. 415–420, May–June, 1989.     

On the “glycogen function” of the myometrium in pregnancy

Summary Investigation was made relative to the physiological significance of the glycogen function of myometrium in pregnancy and of the mechanisms regulating it. The a mount of glycogen in the sections of myometrium lying between individual fetuses was found to be same as in those of non-gravid animals. The glycogen level in myometrium directly bordering on the fetuses was several times greater. The glycogen level in the myometrium of the uterine horn from which the fetuses were removed 3-5-15 days prior to the investigation was lower than in the myometrium of the intact horn containing fetuses. With the development of pregnancy there is a growing resistance of the myometrial glycogen during its incubation in a thermostat at 37°C. This resistance appears to be maximal near the term of pregnancy. The data obtained conforms with the results of previous investigations. It shows that in the control of the glycogen function of myometrium an improtant role is played by the impulses appearing in connection with the vital activity of the fetus and that the physiological significance of this myometrial function is assocated with the requirements of the developing fetus, and probably with its trophics.Presented by Active Member of the AMN SSSR A. I. Serebrov Translated from Byulleten Èksperimental'noi Biologii i Meditsiny Vol. 49, No. 4, pp. 101–104, April, 1960     

Acetylcholine metabolism in the brain of rats treated with vanadyl sulfate and certain phenylacetic acid derivatives

Summary The present work describes the effect produced by phenylacetic acid, phenylethylacetic and diphenylacetic acids (sodium salts) separated and together with vanadyl sulfate on some indices, of acetylcholine metabolism in the rat's brain. Total cholinesterase activity and the free and bound (conditionally) acetylcholine levels served as indices. As shown experimentally the use of phenylacetic acid derivatives is accompanied by reduction of the bound acetylcholine, content, whereas that of free acetylcholine and the total tissue cholinesterase activity remain unchanged. Vanadyl sulfate provokes a significant reduction of the total tissue cholinesterasic activity, but does not change the content of free and bound acetylcholine therein. In conjoint action of the above-mentioned substances, the effects of phenylacetic acid erivatives are supplemented by the anticholinesterase effect of vanadyl sulfate.(Presented by Active Member AMN SSSR S. V. Anichkov) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 57, No. 2, pp. 80–83, February, 1964     

Application of the polymerase chain reaction to study the M protein(-like) gene family in beta-hemolytic streptococci

Evaluation of homologous regions of published M protein (emm) gene sequences from group A streptococci (GAS; Streptococcus pyogenes) was used to design three primer pairs for polymerase chain reaction (PCR) and three oligonucleotide probe sequences internal to the amplified products. One set of primers and corresponding probe should detect and lead to amplification of emm(-like) genes of virtually every type (all M), another (SOR^-M) should only amplify emm(-like) genes from GAS negative for serum opacity reaction (SOR) and the third (SOR⁺M) should expand only emm(-like) genes from SOR⁺ GAS. Using the all M primer pair for PCR on the genomic DNA from GAS of 29 different M types as well as from a group C and a group G streptococcal isolate, DNA fragments within the expected size range were amplified in every assay. All PCR products reacted with the all M probe. Related sequences were not detected in genomic DNA of an S. agalactiae and an Enterococcus faecalis isolate. Applying the SOR^-M and SOR⁺M primers to identical assays led to mutually exclusive amplification products. The SOR⁺M and SOR⁺M probes hybridized only to their corresponding products. Exceptions to this exclusivity were the SOR⁺ GAS of M types 3, 8, 27, 34, 42, 67, and 69, which consistently reacted only with the SOR⁺M primer/probe set. Analysis of sequence data from the amplified emm(-like) 2, 3, 18, and 19 genes revealed interesting specific features such as conserved gaps in the C-terminal sequence regions from SOR⁺ and the exceptional SOR^- GAS strains. These data indicate the existence of a subgroup of strains among SOR^- GAS and may advance our understanding of phylogenetic relationship between different serotypes of GAS.     

A cyclin protein modulates mitosis in the budding yeast Saccharomyces cerevisiae

Summary For the budding yeast Saccharomyces cerevisiae the mitotic cell cycle is coordinated with cell mass at the regulatory step start. The threshold amount of cell mass (reflected as a critical size) necessary for start is proportional to nutrient quality. This relationship leads to a transient accumulation of cells at start, termed nutrient modulation, upon enrichment of nutrient conditions. Nutrient enrichment abruptly increases the critical size needed for start, causing the smaller cells, produced in the previous cell cycle, to be delayed at start while growing larger. Here we show that, in S. cerevisiae, a second cell-cycle step, at mitosis, also exhibits nutrient modulation, and is, therefore, another point of cell-cycle regulation. At both mitosis and start, nutrient modulation was found through mutation to be regulated by the activity of the cyclin-related WHI1 (CLN3) gene product.     

Amygdalar inputs to ADH-secreting supraoptic neurones in rats

Summary Effects of amygdala stimulation on the discharge activity of antidromically identified supraoptic neurosecretory neurones were studied in male rats anaesthetized with urethane. Stimulation of the medial and the basal amygdala produced excitation or inhibition of discharge activity both in phasically firing (phasic) and in continuously firing (continuous) neurones. More phasic neurones were excited than were inhibited after medial amygdala stimulation. On the other hand, fewer continuous neurones were excited by stimulation of the either amygdala area than were inhibited. This difference of responsiveness between phasic and continuous neurones is statistically significant. Synaptic inputs to supraoptic neurosecretory neurones after amygdala stimulation were also observed in rats with a lesion of the stria terminalis. Supraoptic nucleus stimulation activated antidromically 14 of the 336 amygdala neurones tested. Since phasic neurones have been identified as ADH-secreting neurones, it is concluded that ADH-secreting neurones in the rat supraoptic nucleus receive predominantly excitatory synaptic inputs from the medial amygdala and these amygdalar synaptic inputs are mediated by pathways which are at least in part monosynaptic and are not included in the stria terminalis.Supported by the grants nos. 56440079, 56121007 and 56770057 from the Ministry of Education, Science and Culture, Japan     

Effect of the degree of myocardial hypertrophy associated with an experimental heart defect on the resistance to altitude hypoxia

Summary Experimental coarctation of the abdominal aorta with constriction of its lumen to one-third of the original diameter was created in 18 albino rats. Four months later various degrees of myocardial hypertrophy developed in the animals with a relative weight of the heart ranging from 0.0033 to 0.0069. In elevation in the barochamber, the altitude ceiling of the animals with a relative cardiac weight below 0.0040, did not differ from the normal one. The altitude ceiling proved to be considerably decreased in animals with a relative cardiac weight of over 0.0040. Analysis of ECG recorded during the elevation demonstrated that in the animals with a considerable myocardial hypertrophy reduced resistance to the acute high altitude hypoxia depended on the reduction of the functional resistance of the heart.(Presented by Active Member AMN SSSR V. V. Parin) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 55, No. 5, pp. 37–40, May, 1963     

Predictive behavior of optokinetic eye movements

Summary Optokinetic nystagmus is often thought of as a primitive oculomotor response, while smooth pursuit is thought of as a higher one. We have used conditions that are usually thought of as eliciting optokinetic responses; i.e., large-field stimuli confined to the retinal periphery, and instructions to subjects to respond passively. In spite of this, the responses showed predictive behavior similar to that described for smooth pursuit.     

Biophysical studies of teschen disease virus (Talfan strain)

Summary Studies have been made of the heterogeneity of infectivity and CFA in Teschen virus (Talfan strain) suspensions. Most of the infectivity was contained in two components of densities 1.46 gm./ml. and 1.35 gm./ml. The physical, chemical and immunological properties of these components have been compared. It was possible, however, to convert a large proportion of 1.46 component to 1.35 component by treating the 1.46 component with sodium dodecyl sulphate. This would indicate that the 1.46 component was a complex formed between the infective particles and cellular debris.Further studies on the growth characteristics and electron microscopy of the virus have been made.     

Reflexphotometrische Untersuchungen zur Gelbfärbung des Schädeldaches bei Diabetes mellitus

Zusammenfassung Die farbvalenzmetrische Untersuchung von 34 Diabetikerschädeln ergab beim Vergleich mit 56 Kontrollfällen den gleichen Farbton und die gleiche spektrale Sättigung. Bei den Schädeln der Diabetiker ließ sich jedoch eine verminderte Helligkeit nachweisen. Die Farbänderung ist daher für eine Vermutungs-diagnose Diabetes mellitus mit Recht zu verwenden. Es wird jedoch vorgeschlagen, nicht mehr von einer Gelbfärbung, sondern von einer Dunklerfärbung zu sprechen. Das Ausmaß der dunkleren Färbung ist eindeutig positiv zur Krankheitsdauer korreliert. Frühestens nach 6 Jahre bestehendem Diabetes ist eine signifikante Farbänderung zu erwarten. Die Ursache dieser Farbänderung ist unbekannt. In Modellversuchen mit ikterischen Schädeln konnte gezeigt werden, daß die farbmetrischen Kurven bei in vivo entstandenem Ikterus und bei künstlich durch Gallenflüssigkeit erzeugter Verfärbung prinzipiell gleich verlaufen.

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Reflex photometric studies of the yellow discoloration of the calvaria in diabetes mellitus

Summary The shade of color and the spectral saturation of the calvariae of 34 diabetic patients were the same colorimetrically as those of 56 control cases. The calvariae of the diabetics showed, however, a reduced brightness. Consequently, the color change may rightfully be used for the presumptive diagnosis of diabetes mellitus. It is suggested, however, that one should not refer anymore to a yellow discoloration, but instead to a darker discoloration. The degree of the darker color is clearly correlated directly with the duration of illness. The earliest a significant color change may be expected is after six years of diabetes. The cause of the color change is unknown. In model experiments it could be shown, that the colorimetric curves of calvariae discolored by icterus during life are principally the same as the curves of calvariae discolored artificially with bile.

     

Use of B-IV zonal rotor centrifugation as a simple tool for the separation of adeno-associated X7 virus (AAV X7) from helper adenoviruses

Summary The use of zonal rotor centrifugation in the separation of AAV X₇ virus from its helper adenovirus is reported. AAV X₇ virus was perfectly separated from its helper adenovirus. Adeno-associated X₇ virus was found to separate in par tides with an S rate of 72–82 S, and a density in CsCl of 1.30–1.32, and virions with a sedimentation coefficient of 135–147 Svedbergs, with a density of 1.37–1.38.     

Effect of endurance exercise on fibre type composition and muscle weight of reinnervating rat plantaris muscle

The purpose of this study was to evaluate the effect of endurance exercise on the histochemistry and wet weight of the reinnervating rat plantaris muscle. Two groups of young female Wistar rats (6 weeks old), 1 sedentary denervated control (n=13) and 1 excercised denervated experimental (n=17), were denervated unilaterally by cutting and resecting the sciatic nerve. To effect reinnervation a skin grafting operation was carried out on the nerve so that the gap caused by resection was bridged. The third group was the sedentary non-denervated normal control (n=10). A progressive training program of 18 weeks of treadmill running was carried out by the experimental group. Approximately 5 months after denervation, the plantaris muscles were studied histochemically for reduced nicotinamide adenine dinucleotide diaphorase (NADH-D) and mitochondrial alpha-glycerophosphate dehydrogenase (alpha-GPD) activities. Fibres were classified as red, white, or intermediate with NADH-D. Alpha-GPD differentiates intermediate from red fibre types in case of difficulty in differentiating these fibre types from each other with NADH-D. The weight of the reinnervated plantaris muscle increased significantly after exercise. The exerise did not change the fibre type proportions — including red fibre type — in the deep region of the reinnervating plantaris. There were significant differences between normal control and denervated control or experimental groups in histochemical fibre populations in the deep region of the plantaris. The findings of this study suggest that: (a) treadmill running did not increase the oxidative capacity of the deep region of the reinnervating rat plantaris muscle; (b) treadmill training did not damage the reinnervating plantaris; (c) the presence of type grouping following reinnervation was not affected by training (exercise did not interfere with reinnervation).     

Lability in the responses of cells in the auditory cortex of squirrel monkeys to species-specific vocalizations

Summary The activity of 28 cells located mainly in the secondary auditory cortex (A II) of awake squirrel-monkeys, was extracellularly recorded for periods of up to 6 h. Seven different species-specific vocalizations, which were repeatedly presented to the monkey, were used as auditory stimuli. Twenty-six cells responded, at least once, to one or more vocalizations; 22 cells revealed some change in their response (pattern or strength) to at least one vocalization (change in response). Twenty-one cells exhibited a change in the number and/or type of vocalization to which they responded during the recording period (change in selectivity). At some time during the recording period all the responding cells exhibited a change in response and/or a change in selectivity (change in responsiveness). A change in response of a cell to a vocalization did not necessarily exclude a change in selectivity, associated with the same vocalization, later in time and vice-versa. A change in responsiveness to one vocalization was not necessarily correlated with changes in responsiveness to other vocalizations.     

Action of a serum protein on muscular contraction

Summary The mechanism of action of a serum protein isolated from human serum was assessed in several experimental preparations including glycerol-treated muscle fibers, rat heart papillary muscle and isolatedin vitro perfused rat heart. The action of the serum protein was studied also on canine and human heart papillary muscles which were made to respond to electrical stimulation with ultrasonication modified epinephrine. In addition the action of the protein on adenosine 5 triphosphate generated precipitation of purified human actomyosin was investigated.The serum protein enhanced and intensified the generation of ATP induced tension in glycerol-extracted muscle fibers. It intensified the developed tension (DT) and increased the rate of development of tension (dT/dt) without influencing the time peak tension (TPT) of capillary muscles from rat, canine and human hearts in response to electrical stimulation. The serum protein increased the force of contraction of the isolatedin vitro perfused rat heart, and accelerated the adenosine 5 triphosphate generated precipitation of purified human heart actomyosin.     

Neuronal activity in nucleus ambiguus during deglutition and vocalization in conscious monkeys

Extracellular recordings were made from the nucleus ambiguus in three conscious Macaca nemestrina monkeys during spontaneous vocalizations and swallows. The temporal relationship of neuronal activity to swallowing was inferred through correlation with the thyroarytenoid electromyographic (EMG) activity. Videofluoroscopic analysis of a fourth monkey during swallows of barium-impregnated fruit juice established the temporal relationship between swallowing and thyroarytenoid EMG activity. Of 691 cells recorded from the nucleus ambiguus and its adjacent area, the neuronal activity of 80 cells showed modulation during swallowing. Sixty-two cells were classified as active cells, with increased activity in relation to swallowing, while 18 cells were classified as suppressed cells, with tonic activity that reduced with swallowing. A continuum of latency was seen between the onset of modulation of these cells and the onset of swallowing, from early before the swallow to late after the swallow onset with most of the cells (44 cells) showing modulation near the onset of the swallow. A majority (37) of the 62 active swallowing-related cells also discharged with vocalization, but they demonstrated a lower discharge frequency and a longer burst duration during swallowing. Of the 18 suppressed swallowing-related cells, 11 cells discharged phasically with the respiratory cycle and may be a part of the ventral medullary respiratory center. This chronic awake primate model would preserve the many sensory inputs that may modify the oropharyngeal swallow and may better approximate human physiology.     

Functional organization of inferior area 6 in the macaque monkey

Summary The functional properties of neurons located in the rostral part of inferior area 6 were studied in awake, partially restrained macaque monkeys. The most interesting property of these neurons was that their firing correlated with specific goal-related motor acts rather than with single movements made by the animal. Using the motor acts as the classification criterion we subdivided the neurons into six classes, four related to distal motor acts and two related to proximal motor acts. The distal classes are: Grasping-with-the-hand-and-the-mouth neurons, Grasping-with-the-hand neurons, Holding neurons and Tearing neurons. The proximal classes are: Reaching neurons and Bringing-to-the-mouth-or-to-the-body neurons. The vast majority of the cells belonged to the distal classes. A particularly interesting aspect of distal class neurons was that the discharge of many of them depended on the way in which the hand was shaped during the motor act. Three main groups of neurons were distinguished: Precision grip neurons, Finger prehension neurons, Whole hand prehension neurons. Almost the totality of neurons fired during motor acts performed with either hand. About 50% of the recorded neurons responded to somatosensory stimuli and about 20% to visual stimuli. Visual neurons were more difficult to trigger than the corresponding neurons located in the caudal part of inferior area 6 (area F4). They required motivationally meaningful stimuli and for some of them the size of the stimulus was also critical. In the case of distal neurons there was a relationship between the type of prehension coded by the cells and the size of the stimulus effective in triggering the neurons. It is proposed that the different classes of neurons form a vocabulary of motor acts and that this vocabulary can be accessed by somatosensory and visual stimuli.     

Destabilization of herpes simplex virus type 1 virions by local anesthetics,alkaline pH,and calcium depletion

Summary The infectivity of herpes simplex virus type 1 (HSV-1) was found to be markedly reduced by treating virions with the tertiary amine local anesthetics lidocaine, dibucaine and tetracaine. These treatments induced a characteristic shift in the buoyant density of the HSV-1 particles from a light to a heavy population. HSV-1 virions were unstable at alkaline pH, and alkali treatment caused the same shift in buoyant density. Ca²⁺ stabilized the light population. These results suggest that the physicochemical status of the HSV-1 envelope which is sensitive to the treatments described above plays an important role for the integrity of the virion.     

Interactions between Neurons in the Amygdala and Hypothalamus during Conditioned Reflex Behavior Involving Choice of Reinforcement Quality in Cats

The organization of distributed amygdalo–hypothalamic and local amygdalar and hypothalamic neural networks was studied in three cats, trained to perform a food–related operant conditioned reflex to light by the active choice of reinforcement quality method; pressing the pedal with a short latent period provided the cats with a bread/meat mixture, while pressing with a long latent period yielded meat. Animals showed sharp differences in their individual abilities to choose one or the other reinforcement. Two cats preferred long–latency pedal–pressing to obtain meat, and were considered to be self–controlled, while the third cat, which preferred short–latency pedal–pressing to obtain the less valuable reinforcement (the bread/meat mixture) was described as impulsive. Chronically implanted semimicroelectrodes were used to record multineuron activity in the basolateral nucleus of the amygdala and the lateral nucleus of the hypothalamus. Interactions between the discharge trains of neighboring and distant neurons were assessed by cross–correlation analysis. Interneuron functional connections were found to predominate significantly in the local neural networks of the basolateral amygdala and distributed amygdalar–hypothalamic networks in the impulsive animal as compared with the self–controlled animals, suggesting a role for these types of connection in forming the individual characteristics of higher nervous activity. The identical incidences of interneuron interactions in the lateral nucleus of the hypothalamus in cats with different individual preferences suggest that local networks in this formation are not involved in analyzing reinforcement quality.     

Evaluation of mouse monoclonal antibodies raised against an isolate of the variant avian paramyxovirus type 1 responsible for the current panzootic in pigeons

Summary Nine monoclonal antibodies raised against pigeon variant avian paramyxovirus type 1 isolate pigeon/England/617/83 were tested for their ability to react with classical and other pigeon variant isolates. Two of the monoclonal antibodies appeared to be specific for 617/83 reacting with no other virus. The remaining seven monoclonal antibodies bound to cells infected with all other pigeon isolates in indirect immunoperoxidase (IIP) tests but four distinct groups of other PMV-1 viruses were formed on the basis of the binding patterns. One of the monoclonal antibodies 161/617 caused haemagglutination inhibition (HI) of all the pigeon isolates tested but none of the other PMV-1 viruses and these results reflected the IIP results with this monoclonal antibody.161/617 was also shown to inhibit viruses of the avian paramyxovirus type 3 serogroup in HI tests. This reaction and the ability to bind to infected cells in IIP tests appeared to be restricted to PMV-3 viruses isolated from exotic birds and did not occur with viruses of ostensively the same serotype from turkeys.