bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adipose tissue and heat production in the new‐born ox (Bos taurus)
Authors: Jenkinson D. McEwan , Noble R. C. , Thompson G. E. 
Published: December 2014

1. A histological examination of adipose tissue from 1‐ and 6‐day‐old calves showed a structure typical of white adipose tissue and no evidence of brown adipose tissue.2. Infusion of noradrenaline (1·0 μg/kg.min
I.V.) into 1‐to 6‐day‐old calves affected heart rate and respiratory rate but did not increase heat production, rectal temperature, skin temperature or skin evaporative loss.3. Cold exposure led to shivering and an increased oxygen consumption in the 6‐day‐old calf.4. Blood samples taken from 6‐day‐old calves in the cold (‐1° C) appeared to have a higher proportion of unesterified fatty acids in the total blood lipid than samples taken in an environment of 20° C, but no change in fatty acid composition was found.5. It has been concluded that there is no non‐shivering thermogenesis in the young calf.
On the mechanism by which calcium and magnesium affect the release of transmitter by nerve impulses
Authors: Hubbard J. I. , Jones S. F. , Landau E. M. 
Published: December 2014

1. The relationship between the quantal content of end‐plate potentials (e.p.p.s) and the bathing [Ca] and [Mg] was determined at neuromuscular junctions in the rat diaphragm in vitro.2. E.p.p.s were recorded intracellularly from preparations exposed to solutions with [Ca] between 0·05 and 10 m
M and [Mg] between 0·1 and 12·5 m
M. The quantal content of e.p.p.s was increased by raising the [Ca] over this range and decreased by raising the [Mg]. There appeared to be competition of Mg with Ca at three sites in the nerve terminal membrane.3. A kinetic scheme based on competition of Ca and Mg at three sites could quantitatively explain the effects of Ca and Mg upon the quantal content of e.p.p.s and also the effects of these ions upon miniature end‐plate potential frequency.
Rate limiting processes in the bohr shift in human red cells
Authors: Forster R. E. , Steen J. B. 
Published: December 2014

1. The rates of the Bohr shift of human red cells and some of its constituent reactions have been studied with a modified Hartridge—Roughton rapid reaction apparatus using an oxygen electrode to measure the progress of the reaction.2. The rate of the Bohr shift was compatible with the hypothesis that the transfer of H+ across the membrane by means of CO2 exchange and reaction with buffers is generally the rate‐limiting step.(a) When the Bohr off‐reaction was produced by a marked increase in PCO2 around the cells, the half‐time at 37° C was 0·12 sec. In this case CO2 was available initially to diffuse into the cells, the process being predominantly limited by the rate of intracellular CO2 hydration.(b) When the Bohr off‐shift was produced by an increase of [H+] outside the cell, PCO2 being low and equal within and outside the cells, the half time became 0·31 sec. In this case, even at the start, the H2CO3 formed by the almost instantaneous neutralization reaction of H+ and HCO3− had to dehydrate to form CO2 and this in turn had to diffuse into and react within the red cell before the [HbO2] could change. When a carbonic anhydrase inhibitor was added to slow the CO2 reaction inside the cell, the half‐time rose to 10 sec.(c) The Bohr off‐shift in a haemolysed cell suspension produced by an increase in PCO2 appeared to be limited by the rate at which the CO2 could hydrate to form H+.3. The Bohr off‐shift has an average Q10 of 2·5 between 42·5 and 28° C with an activation energy of 8000 cal.4. The pronounced importance of the CO2‐bicarbonate system for rapid intracellular pH changes is discussed in connexion with some physiological situations.
Recurrent inhibition in sacral parasympathetic pathways to the bladder
Authors: de Groat W. C. , Ryall R. W. 
Published: December 2014

1. The effects produced by stimulation of the central end of transected ventral roots were observed on spontaneous and evoked vesical contractions and on the firing of sacral parasympathetic neurones.2. Recurrent inhibition of sacral parasympathetic neurones was demonstrated at frequencies of stimulation above 10/sec and at intensities above threshold for the parasympathetic axons.3. Recurrent inhibition was present in chloralose cats, as well as in decerebrate animals and was unaffected by chronic spinal transection.4. Interneurones were located which are presumed to be the autonomic equivalents of the somatic Renshaw cells. They were synaptically activated by antidromic stimulation of preganglionic fibres in sacral ventral roots.5. The inhibition of vesical contractions and the firing of the interneurones was reduced when the intravesical pressure was raised.6. The recurrent inhibition was unaffected by the intravenous injection of dihydro‐β‐erythroidine.7. Strychnine reduced the recurrent inhibition in some experiments but the results were inconsistent. The effects of picrotoxin were inconclusive.8. The possible role of recurrent inhibition in micturition is discussed.
Response of lymphatics of canine hind limb to sympathetic nerve stimulation
Authors: Browse N. L. 
Published: December 2014

1. The changes in lymphatic pressure in a limb whose circulation was temporarily arrested with a pneumatic cuff have been studied.2. Stimulation of the lumbar sympathetic chain caused an increase in lymphatic pressure. It has been shown that this is a primary not a secondary phenomenon, due to an active lymphomotor mechanism.3. The increase of lymphatic tone is proportional to the rate of stimulation; peak values are reached between 5 and 9 impulses/sec.
Natriferic and hydrosmotic effects of neurohypophysial peptides and their analogues in augmenting fluid uptake by Bufo melanostictus
Authors: Elliott Annie B. 
Published: December 2014

1. The effect of intramuscular injection of 8‐arginine vasotocin, 8‐arginine vasopressin, 8‐lysine vasopressin, oxytocin, 8‐ornithine oxytocin and 8‐ornithine vasopressin on fluid uptake across the skin was studied in the live toad, Bufo melanostictus, bathed either in distilled water or in NaCl solution (0·1 g/100 ml.).2. When the bathing solution was distilled water, 8‐arginine vasotocin was the most potent, 0·14 nmole/kg augmenting the rate of fluid uptake by 50%. Compared with it the others had relative potencies of: 8‐arginine vasopressin 0·8, 8‐lysine vasopressin 0·8 × 10−3, oxytocin 0·8 × 10−3, 8‐ornithine oxytocin 0·8 × 10−2, 8‐ornithine vasopressin < 1·4 × 10−4.3. When the bathing solution contained 0·1% NaCl, 8‐arginine vasotocin was again the most potent, 0·06 nmole/kg augmenting the rate of fluid uptake by 50%. Compared with it the others had relative potencies of: 8‐arginine vasopressin 0·3, 8‐lysine vasopressin 0·3 × 10−3, oxytocin 0·3 × 10−2, 8‐ornithine oxytocin 0·8 × 10−2, 8‐ornithine vasopressin < 0·6 × 10−4.4. Dose—response curves for each peptide showed that in the case of 8‐arginine vasopressin, 8‐lysine vasopressin and 8‐ornithine vasopressin the augmentation of rate of fluid uptake did not differ in the absence or in the presence of NaCl in the bathing solution; whereas in the case of 8‐arginine vasotocin, oxytocin, and 8‐ornithine oxytocin the augmentation was greater in the presence of sodium chloride.5. Support has been found for the postulate of a binary action of some neurohypophysial peptides on amphibian skin, arginine in position 8 being correlated with hydrosmotic effect, and isoleucine in position 3 with natriferic effect.
Colour‐coded ganglion cells in the goldfish retina: extension of their receptive fields by means of new stimuli
Authors: Daw Nigel W. 
Published: December 2014

1. Receptive fields of colour‐coded ganglion cells of the goldfish retina were investigated.2. Only a few cells (5%, Type P) were found to be as simple as those described by Wagner, MacNichol & Wolbarsht (1960, 1963), with an ‘on’ response to red light in the centre, and an ‘off’ response to green light over a rather wider area, or vice versa.3. Most cells (49%, Type O) also gave a peripheral response with an ‘on’ response to green light, and an ‘off’ response to red light in the periphery, as well as an ‘on’ response to red light and an ‘off’ response to green light in the centre (or vice versa).4. When a small spot of light was used to stimulate the periphery of a Type O cell, the peripheral response usually was not obtained. The organization of the periphery is such that a stimulus of large area and low intensity (annulus) is much more effective than a stimulus having equal energy with small area and high intensity (spot). If only small spots are used, the Type O cell is indistinguishable from the Type P cell.5. Spectral sensitivity measurements show that one central and one peripheral process are fed primarily by red‐absorbing cones, and the other central and the other peripheral process by green‐absorbing cones or rods.6. The diameter of the receptive field as a whole is very large, being 5 mm or more on the retina.7. When red spots in green surrounds, or red/green boundaries are used as stimuli, the response can be predicted by summing the responses to the components of the stimulus.8. This type of receptive field organization is appropriate to mediate simultaneous colour contrast. The ‘opponent colour’ organization previously reported is appropriate for successive colour contrast, but not for simultaneous colour contrast.9. The component of the response coming from the green‐absorbing cones was masked or hidden by the component of the response coming from the red‐absorbing cones in 14% of the units (Type Q units). The component from the green‐absorbing cones was revealed by using a high intensity of stimulation, or by observing the response after bleaching pigment with an intense red light.
Osmotic stability of blood platelets
Authors: Fantl P. 
Published: December 2014

1. Hypotonic solutions added to human platelet‐containing plasma cause a transient decrease of absorbancy of light at 610 mμ which is followed by a gradual increase of absorbancy.2. When platelets are stored for 7 hr at 4° C the absorbancy changes with variations of osmolarity and their aggregation with adenosine diphosphate (ADP) remain the same. However, the reversal of absorbancy declines during storage of platelet‐containing plasma.3. Platelets are not aggregated by stearate. Platelets appear to be only slightly affected by stearate concentration higher than 0·8 m
M, but oleate has no effect.4. Hypertonic solutions of NaCl and urea cause increase in absorbancy of platelet‐containing human plasma. Hypertonic sucrose solutions produce no more change than isotonic solutions. Hypertonic NaCl produces permanent increases in absorbancy. In human platelet‐containing plasma the increased absorbancy caused by hypertonic urea is transient and declines.5. The osmotic platelet changes occur in isolated platelets as well as in platelet‐containing plasma.6. The absorbancy of frozen and thawed platelet‐containing plasma is not significantly altered by hypotonic solutions but the absorbancy changes caused by hypertonic solutions are similar to that of unfrozen plasma.7. The immediate absorbancy changes caused by hypo‐ and by hypertonic solutions are the same at 5° C and 30° C and are therefore probably of a physical nature. The reversal of absorbancy and aggregation of platelets by added adenosine diphosphate have Q10 > 1 and are therefore probably of a chemical‐enzymic nature.8. Divalent cations and contact activation are not required for the osmotic platelet changes and 10μ3
M‐Cu2+ and Zn2+ do not interfere. Inhibitors of oxidative phosphorylation, electron transfer, sodium, potassium activated adenosine triphosphatases and adenosine triphosphate do not inhibit reversal of absorbancy of platelets exposed to hypotonic solutions. Cyanide, 5 × 10μ3
M, fluoride, 1·23 × 10μ2
M, iodoacetamide, 10μ2
M, are moderately effective inhibitors. At hydrogen ion concentrations above pH 8, complete inhibition occurs.9. N‐ethyl‐maleimide, 10μ3
M, and mercloran inhibit completely reversal of absorbancy, indicating the necessity for sulphydryl compounds.10. Intact platelets are essential for the reversal of absorbancy after hypotonic swelling. Osmotic changes by hypotonic solutions are independent of ADP aggregation of platelets.
The angular selectivity of visual cortical cells to moving gratings
Authors: Campbell F. W. , Cleland B. G. , Cooper G. F. , Enroth-Cugell Christina 
Published: December 2014

1. Grating patterns were used to obtain a quantitative description of cells in the visual cortex of the cat whose response amplitude depended critically upon the orientation of the moving grating.2. In all such cells the impulse frequency was found to decrease linearly with angle on either side of an optimum angle (the preferred angle) until the response fell to zero or to a base frequency. The angular rate of change of response varied between cells and was expressed as the half‐width at half amplitude (the angular selectivity).3. The angular selectivity of thirty‐five cells was determined and more than half (nineteen) of these fell within the range 14‐26°.4. Fourteen cells responded optimally only when the grating was moved in one direction. Twenty‐one cells responded optimally to two directions of movement 180° apart, but the response in the two directions was not always equal.5. No significant correlation was found between the response amplitude at the optimum angle and the angular selectivity.6. The distribution of preferred angles did not show any difference between the oblique orientations and the vertical and horizontal orientations.7. These results are compared with a previous psychophysical estimate of angular selectivity.
Diuretic responses to water‐load in four strains of mice
Authors: Stewart J. 
Published: December 2014

1. The kinetics of excretion of water, sodium and potassium following a stomach load of water, with and without an initial injection of vasopressin, are described in each of four strains of mice: RAP, CBA/FaCam, Peru and A/Cam.2. In general there was a diuretic lag followed by an increase in the rate of excretion of water to a maximum, after which the rate of excretion fell again to near resting levels. The rate of excretion of sodium rose to an initial maximum which significantly preceded the maximum rate of water excretion. The rate of excretion of sodium then fell to a minimum at a time not significantly different from the time of maximum rate of water excretion.3. The effect of an initial injection of vasopressin was to increase and to prolong the initial rise in rate of sodium excretion. The maximum rate of water excretion and the minimum sodium concentration were delayed, but the levels eventually reached were not significantly altered, by the vasopressin injection.4. The strains of mice differed significantly in diuretic lag, maximum rate of diuresis, and 3 hr excretion of water and electrolytes.5. The strains also differed significantly in the effects of vasopressin, both in increasing diuretic lag and in increasing sodium excretion. There was no correlation between the antidiuretic and natriuretic effects of vasopressin.
The influence of hypothalamic temperature and ambient temperature on thermoregulatory mechanisms in the pig
Authors: Baldwin B. A. , Ingram D. L. 
Published: December 2014

1. Two types of temperature fluctuation have been recorded from the preoptic region of the conscious pig. One, which is associated with arousal or movement, and another, which is related to rhythms in respiration and blood pressure.2. When the pigs were subjected to infra‐red irradiation at various ambient temperatures it was found that there was no precise temperature of the preoptic region at which the respiratory frequency increased.3. Local heating of the preoptic region was effective in increasing the respiratory frequency only when the ambient temperature was above 30° C.4. Even when both the peripheral temperature and central temperatures were increased there was a delay of several minutes before the onset of panting.5. Cooling the preoptic region of the hypothalamus prevented the onset of panting in a hot environment, and reduced respiratory frequency in an animal which was already panting.6. Oxygen consumption was reduced in a cold environment when the preoptic region was warmed, and increased when it was cooled. No increase in oxygen consumption occurred when the hypothalamus was cooled in a hot environment.
Finger blood flow in Antarctica
Authors: Elkington E. J. 
Published: December 2014

1. Finger blood flow was estimated, by strain‐gauge plethysmography, before and during a 1 hr immersion in ice water, on twenty‐five men throughout a year at Wilkes, Antarctica. A total of 121 satisfactory immersions were made.2. Blood flow before and during immersion decreased significantly in the colder months of the year, and the increase caused by cold‐induced vasodilatation (CIVD) became less as the year progressed. The time of onset, blood flow at onset, and frequency of the cycles of CIVD showed no significant relation to the coldness of the weather (as measured by mean monthly wind chill) or the time in months. Comparisons of blood flow before and after five field trips (average duration 42 days), on which cold exposure was more severe than at Wilkes station, gave similar results.3. The results suggest that vasoconstrictor tone increased. This interpretation agrees with previous work on general acclimatization in Antarctica, but contrasts with work elsewhere on local acclimatization of the hands.
Intracellular recording from mammalian superior cervical ganglion in situ
Authors: Erulkar S. D. , Woodward J. K. 
Published: December 2014

1. Recordings have been obtained by intracellularly placed microelectrodes from cells of the superior cervical ganglion of the rabbit. The ganglion was left in situ.2. In response to stimulation of the external carotid nerve, some cells responded with a single spike of short latency followed by a long‐lasting hyperpolarization. These cells, presumably, were activated antidromically. The majority of cells, however, responded with an early spike followed by a long‐lasting depolarization; superimposed on this depolarization were one or two spikes with latencies from 35 to 70 msec. Anatomical pathways responsible for this activation have been suggested.3. A variety of responses were recorded from different neurones when the preganglionic sympathetic trunk was stimulated. Many of the cells responded to maximal stimulation of the nerve with repetitive spikes. Stimuli of constant strength could elicit variable responses from a single neurone. This variability and the multiple spike response may be due to multiple pathways leading to the same cell and the possibility of the presence of internuncial neurones in the ganglion is suggested.4. Strong stimulation of the preganglionic sympathetic nerve trunk caused inhibitory effects at the ganglion cells.5. Direct stimulation of the ganglion cells through the recording microelectrode elicited only one spike even at high intensity. Thus the multiple spike response to orthodromic stimulation must have been due to a temporally dispersed afferent input.6. It is concluded that the organization of the rabbit superior cervical ganglion is more complex than has been suspected previously, and that integration as well as transmission takes place at the level of these neurones.
Tension due to interaction between the sliding filaments in resting striated muscle. the effect of stimulation
Authors: Hill D. K. 
Published: December 2014

1. A resting sartorius muscle of the frog or toad possesses a special kind of elasticity which is shown to be due to a component lying between the two sets of filaments. The elastic effect is seen only for very small length changes, up to about 0·2% of the muscle length, and the ‘elastic limit’ is then reached. If the length change then continues at a constant velocity the tension developed is maintained at a fixed level, producing a sort of frictional resistance. The component responsible is called the ‘short‐range elastic component’, or SREC.2. It is also shown that a small part of the permanent tension of a resting muscle is probably due to ‘active’ interaction between the filaments. This is called the ‘filamentary resting tension’, or FRT. For a sarcomere length of 2·0 μ the FRT amounts to about 150 mg in a muscle weighing 100 mg.3. The stiffness of the SREC and the magnitude of the FRT are shown to be related to one another. They are both increased, and may rise to high values, by making the external solution hypertonic.4. The working hypothesis is as follows. In a resting muscle the cross‐bridges on the myosin filaments are not entirely inactive, but a very small proportion of them are cross‐linked with the actin filaments. The links are very stable and have a long ‘life’. The elastic behaviour is due to the flexural rigidity, or spring‐like properties of these bridges. The elasticity is ‘short‐range’ because the bridges can be bent, or stretched, only a small way from the steady‐state position before the contacts ‘slip’. The ‘filamentary resting tension’ (which is present in the absence of any external length change) is attributed to an ‘active process’, which operates by imparting ‘organized’ potential energy to the participating cross‐bridges, by potentiating their attachment, against their elastic resistance, to sites on the actin filaments which are displaced towards the Z line.5. It is shown that the ability of the muscle to maintain a ‘frictional’ resistance to a continuing, slow, length change is suppressed during a maintained tetanic contraction. The process of suppression starts during the period of the latency relaxation.6. It is suggested that the latency relaxation may be due to a reduction of the filamentary resting tension.7. The experiments with the latency relaxation were facilitated by the use of strongly hypertonic solutions. The positive twitch tension is then greatly reduced, or may be practically abolished, while the latency relaxation remains at about its normal size and is extended in duration.
Termination and functional organization of the dorsal spino‐olivocerebellar path
Authors: Oscarsson Olov 
Published: December 2014

1. The spino‐olivocerebellar path ascending through the dorsal funiculus (DF‐SOCP) was investigated in decerebrate cats with the cord transected in the third cervical segment except for the dorsal funiculi. The climbing fibre responses evoked in Purkinje cells were studied by recording the mass activity at the cerebellar surface and by recording from single cells.2. The DF‐SOCP forms a disynaptic path from the spinal cord to the cerebellar cortex as shown by latency measurements. Anatomical studies have recently demonstrated that the relays are in the rostral part of the dorsal funiculus nuclei and in the dorsal accessory olive.3. The DF‐SOCP projects to sagittal zones in the pars intermedia and vermis of the anterior lobe. The somatotopical organization is predominantly transverse in the pars intermedia and predominantly longitudinal in the vermis.4. The olivary neurones in the DF‐SOCP are activated by the flexor reflex afferents from wide receptive fields. The fields are restricted to one ipsilateral limb and the majority of the olivary neurones could be activated from all the nerves tested in this limb.5. Natural stimulation of receptors evoked excitation in about half of the olivary neurones investigated. This excitation was elicited by pressure against deep structures. Inhibitory effects were rarely observed.6. The dorsal and ventral spino‐olivocerebellar paths are compared.