Functional differentiation of crayfish statocyst receptors in sensory adaptation

• 1.1. Response characteristics of tonic- and phasic-type receptors in the crayfish statocyst were investigated with intracellular recording technique.
• 2.2. They were identified to be either tonic- or phasic-type according to their response patterns to the hair deflection performed by water jet stimulation.
• 3.3. Constant depolarizing current applied intracellularly evoked long-lasting spike discharge in the tonic-type neurons and transient discharge in the phasic-type neurons.
• 4.4. These tonic- and phasic-type neurons also showed different patterns of spike discharge to depolarizing pulse stimulus of 50 msec duration.
• 5.5. On the basis of the response patterns to this pulse stimulus, it was shown that the statocyst receptor neurons consist of 46% tonic- and 54% phasic-type neurons.

     

Sensory and motor innervation of bird intrafusal muscle fibers

• 1.1. Most bird muscle spindles are supplied by only one primary afferent.
• 2.2. Secondary afferents occur irregularly.
• 3.3. Sensory terminals are covered by a basal lamina and a collagenous sheath.
• 4.4. Two types of motor terminal are recognized which can be referred to specific types of intrafusal fiber.
• 5.5. The sensory and motor innervation of bird intrafusal fibers is less understood than that of mammalian intrafusal fibers.

     

The morphology and physiological properties of nereid giant fibres

• 1.1. The three sets of giant fibres in the nerve cord of Nereis virens are connected by both electrotonic and chemically transmitting junctions.
• 2.2. The paired laterals and paramedials are connected to their partners by electronic junctions. The laterals are also electrically coupled to the median giant fibre.
• 3.3. The laterals are connected to the paramedials by an excitatory chemical synapse, while in the anterior segments the paramedials provide an inhibitory input to the median giant fibre.
• 4.4. Afferent input to the giant fibres through the segmental nerves two and four is excitatory, except that to the median fibre in the caudal segments.
• 5.5. There is no evidence of the segmental origin of the lateral giant fibres, either in the form of macrosynapses or segmental cell bodies.
• 6.6. The median giant fibre originates from two groups of cell bodies in the sub-oesophageal ganglia.

     

Hormonal stimulation and differential growth response of renal epithelial cells cultivated in vitro from individual nephron segments

• 1.1. Nephron segments (rabbit) were dissected and explanted into primary culture.
• 2.2. Outgrowth of epithelial cells and proliferation in monolayer from distal nephron segments was dependent upon cell substratum (plasma or collagen) and upon hormonal supplements of serum-free media.
• 3.3. Distal nephron segments from cortex and outer medulla (thick ascending loop of Henle, collecting tubule) have differential requirements for growth-stimulation.
• 4.4. Proximal epithelial tissue (embryonic Nephron Anlage) depends on serum or embryo extract for differentiation into convoluted segments.
• 5.5. The mammalian nephron can be cultivated in vitro to form segmental epithelial monolayers.

     

Optical and neural pooling in visual processing in crustacea

• 1.1. Optical pooling is common in crustacean vision, both pooling in the single ommatidium and pooling inputs from many ommatidia by overlapping visual fields.
• 2.2. Optical and neural pooling work together subdividing the eye into different surface regions with different tasks.
• 3.3. Small-fiber and large-fiber systems with corresponding small and large dendritic branching provide a parallel processing system.
• 4.4. Several parallel, integrating channels process that visual information which is needed for high-speed reactions.
• 5.5. Visual fibers receive contributions from other modality inputs like vibration, olfaction or attention neurons. Inputs from mechanoreceptors transmitted over integrating fibers seem to join the signals in the intergrating visual fibers.
• 6.6. The signal for a particular channel is expressed by the pattern of spikes (rather than changes in the mean frequency of spikes) which is modulated by any input variation.
• 7.7. A particular discharge pattern may then be recognized by a command neuron or a muscle ensemble.

     

Morphology of leech retzius cells demonstrated by intracellular injection of horseradish peroxidase

• 1.1. The neuronal geometry of Retzius (R) cells in two species of leech (Hirudo medicinalis and Haemopis sanguisuga) was investigated by intracellular injection of horseradish peroxidase.
• 2.2. Each R cell sends major branches into the ipsilateral segmental nerves and, via the ipsilateral connectives, into the anterior and posterior adjacent ganglia.
• 3.3. No structural connection between the proximal axons of the two R cells could be detected, although numerous dendrites were demonstrated, some of which extended across the midline of the ganglion.
• 4.4. No major differences were found between the R cell morphology of the two species.

     

Characterization of the Melanoplus sanguinipes hemolymph after infection with Beauveria bassiana or wounding

• 1.1. The phenoloxidase activity, protein and carbohydrate levels were studied for 24 hr in the hemolymph of the migratory grasshopper, Melanoplus sanguinipes after artificial wounding of the insect cuticle or the injection of Beauveria bassiana conidia.
• 2.2. Injection or wounding induced a primary response and phenoloxidase activity was found to increase within 10–60 min. The values for phenoloxidase activity in viable B. bassiana-injected insects exhibited a secondary response, i.e., an increase 24 hr after injection.
• 3.3. In wounded insects and those injected with inactivated conidia, the phenoloxidase activity receded after the initial increase and remained at low levels.
• 4.4. Protein concentrations in the hemolymph increased immediately after infection and wounding and returned to basal levels during the course of the experiment.
• 5.5. Injection of viable B. bassiana resulted in a gradual increase in the protein concentrations between 12 and 24 hr.
• 6.6. There was no apparent change in the carbohydrate levels in either B. bassiana-infected or wounded insects.
• 7.7. These results are discussed in relation to their possible role(s) and interrelationships in the immune response to infection or wounding. Furthermore, we suggest that a “factor” is released after mechanical injury of the integument.

     

2-Deoxyglucose transport by the frog sartorius: Effects of electrical stimulation and N-carbobenzoxy-glycyl-l-phenylalaninamide

• 1.1. Studies characterizing glucose transport in the frog sartorius were performed.
• 2.2. For nonstimulated and stimulated muscles, intracellular 2-deoxyglucose exceeded 2-deoxyglucose-6-phosphate at 15 min, showed little further increase, and was maintained below the extracellular concentration for 2 hr.
• 3.3. Accumulated 2-deoxyglucose-6-phosphate did not inhibit glucose transport.
• 4.4. Unlike in adipocytes, basal and stimulated 2-deoxyglucose transport showed no difference in sensitivity to N-carbobenzoxy-glycyl-l-phenylalaninamide.
• 5.5. Phenylarsine oxide blocked contraction-enhanced 2-deoxyglucose uptake.
• 6.6. These results suggest that the glucose transporter of the sartorius exhibits auto-regulation, and that basal transport is not regulated by the same process as in adipocytes.

     

Feeding and a serotonergic interneuron activate an identified autoactive salivary neuron in Limax maximus

• 1.1. A single neuron is found in each buccal ganglion of the giant garden slug, Limax maximus, which is autoactive and has an axon in both the ipsilateral and contralateral salivary nerve.
• 2.2. This neuron, the bilateral salivary neuron (BSN), is a slow bursting neuron and is presynaptic to some of the secretory acinar cells of the salivary gland.
• 3.3. Increases in BSN action potential frequency and saliva flow during the generation of feeding motor program are shown, as is the relationship of BSN activity to that of other salivary neurons.
• 4.4. BSN is affected synaptically by the serotonergic metacerebral giant cell.

     

Induction kinetics of immune antibacterial proteins in pupae of Galleria mellonella and Pieris brassicae

• 1.1. Pupae of Galleria mellonella and Pieris brassicae given an injection with live, non-pathogenic Enterobacter cloacae or abiotic foreign molecules induce an acquired immunity that corresponds with the synthesis of haemolymph proteins of antibacterial activity.
• 2.2. This humoral defensive response which persists for several days, differs quantitatively between insect species and between the inducers used, although very different foreign bodies induced the same immune proteins in both lepidopteran insects.
• 3.3. A stronger and longer lasting response was consistently noticed in pupae immunized with non-pathogenic bacterium than after sterile nutrient broth injections.
• 4.4. A demonstrably elevated activity of haemolymph lysozyme and trace activity of cecropins found in pupae of Galleria treated with saline W, a salt solution physiological to moths, disappear soon after 36 hr from injection.
• 5.5. In P. brassicae, however, sterile insect Ringer can give a varying, if present at all, immune response.
• 6.6. A mechanical injury (sterile wounding of insect body) can occasionally induce a similar but much weaker response.
• 7.7. The antibacterial activity was drastically reduced in Pieris or completely depressed in most pupae of Galleria when actinomycin D or cycloheximide was given at an early time post-immunization with E. cloacae.
• 8.8. It is concluded that the de novo synthesis of ribonucleic acid and immune proteins is required for expression of antibacterial activity in pupal haemolymphs.
• 9.9. The synthesis of an immune mRNA was completed about 7 hr after the injection of the immunizing bacteria.

     

Increased muscle glucose uptake in response to chronic glyburide treatment is not related to changes in glucose transporter (GLUT4) protein

• 1.1. The mechanism of action of glyburide (a sulfonylurea) on muscle has been investigated by measuring glucose uptake and glucose transporter (GLUT4) protein levels after chronic glyburide treatment.
• 2.2. A dietary induced insulin resistant rat model (4 wk of high-fat, high-sucrose feeding) was given glyburide (2mg/kg/day) for 10 days and glucose uptake was measured in a perfused hindquarter preparation.
• 3.3. Protein levels of the GLUT4 glucose transporter were determined by Western analysis.
• 4.4. After 7 days of treatment, rats fed glyburide had lower blood glucose concentrations 2 hr (72 ± 5 vs 103 ± 12 mg/dl) and 24 hr (97 ± 7 vs 123 ± 7 mg/dl) after glyburide administration with no difference in serum insulin levels compared to vehicle treated animals.
• 5.5. Glucose uptake was approx doubled in basal state (0 insulin) in response to glyburide (2.8 + 0.4 vs 1.7 ± 0.2μ mol/g per hr).
• 6.6. Maximal insulin (100 nM) stimulated glucose uptake tended to be higher in the glyburide treated group, but did not reach statistical significance (8.0 ± 0.7 vs 7.0 ± 0.6 μmol/g per hr).
• 7.7. Western analysis revealed no significant effect of glyburide on the GLUT4 protein level in skeletal muscle.
• 8.8. These results suggest that glyburide alters glucose uptake through some mechanism other than alterations in the level of the GLUT4 glucose transporter protein.

     

Protein,fatty acids,calcium and phosphate absorption along the gastrointestinal tract of the young turkey

• 1.1. The net absorption of protein, fatty acids, calcium and phosphate along the small intestine of the turkey (Meleagris gallopovo) was evaluated with the aid of ⁹¹Y as a reference substance.
• 2.2. About 85% of the ingested protein was absorbed, with most of the absorption occurring in the duodenum and upper jejunum.
• 3.3. The overall lipid absorption coefficient was around 90%, and was inversely related to the fatty acid chain length and saturation.
• 4.4. Most of the lipid absorption occurred in the duodenum and jejunum.
• 5.5. Calcium absorption also occurred in the duodenum and jejunum: its fractional rate decreased with calcium intake.
• 6.6. Phosphate absorption occurred mostly in the duodenum and jejunum and its efficacy was only slightly affected by dietary phosphate intake.
• 7.7. The high nutrient absorption in the turkey duodenum, relative to that of the chick (Gallus domesticus), was discussed.

     

A hypothesis on protein folding in vivo

• 1.1. A hypothesis on protein folding in vivo based on the Poincare recursion argument is proposed and discussed.
• 2.2. It is postulated that protein folding in vivo proceeds through prefolded peptide segments which consist of 3 to 14 amino acids.
• 3.3. It is also shown that circular dichroism spectroscopy can successfully be applied for monitoring of the appearance of the correct tertiary structure of proteins.

     

Identification of neurons involved in the earthworm Amynthas hawayanus reflex activity

• 1.1. The medial (MGF), lateral (LGF) and motor (RMS-2) giant neurons were confirmed as neural components in the earthworm Amynthas hawayanus polysynaptic reflex circuit by simultaneous potential recording and dye injection.
• 2.2. The reflex was initiated from the mechanoreceptors when evoked by mechanical stimulation but electrical stimulation also evoked an antidromic response in the motoneuron.
• 3.3. The primary reflex response propagates decrementally along both giant axons but directly evoked action potentials conduct in an all-or-none fashion.
• 4.4. The secondary reflex response continues to propagate after the primary response disappears.
• 5.5. A rhythmically discharging neuron of uncertain function was also identified.

     

Influence of ions and chemical substances on the response of the frog's tongue to mechanical stimulation

• 1.1. The fungiform papillae responded to the mechanical stimulation of either an air puff or a Frey's hair. but the filiform papillae did not.
• 2.2. The integrated neural response to an air puff was greatest along the margin and at the apex of the dorsum linguae.
• 3.3. More than three quarters of the mechanosensitive fibers responded to CaCl₂ application and one third responded to NaCl application. Mono- and divalent cations had various influences on the response to mechanical stimulation.
• 4.4. Glucose and sucrose dissolved in distilled water depressed the response, but when dissolved in Ringer's solution had no effect. HCl and quinine-HCl depressed the mechanical response.

     

Human-induced tachycardia in wild and tame mallard (Anas platyrhynchos)

• 1.1. The effect of regular handling on fear reactions was investigated in mallard (Anas platyrhynchos) by exposing six hand-reared and four wild ducks to an approaching human being and recording heart rates with an external ECG device.
• 2.2. All ducks reacted to the approach with tachycardia, but the response was significantly less in tame birds.
• 3.3. Hand-reared females showed less response than males. No sex-linked differences were apparent in the wild ducks.
• 4.4. Decreasing responses throughout the experiments were only found in tame birds.
• 5.5. Fear or stress reactions can apparently be diminished through habituation induced by regular handling.

     

Carbonic anhydrase III content in various equine muscles

• 1.1. In this study, carbonic anhydrase III (CA-III) content in 18 equine muscles was determined by enzyme immunoassay.
• 2.2. It was found to differ in several muscles.
• 3.3. That in external intercostal muscle, rectus abdominis muscle and splenius muscle from four horses was very high.
• 4.4. Although the masseter muscle had only type I fibers, CA-III content was similar to that in mixed-fiber type muscles such as the biceps femoris muscle.
• 5.5. It thus appear that equine type I fibers can be further subgrouped.

     

Effects of temperature and acid stress on hatching,survival capacity,metabolism and postural reflexes in caenid mayflies (ephemeroptera)

• 1.1. Mortality was 100% at pH 3.5 over a temperature range of 10–30°C for embryos and nymphs of Caenis diminuta and C. hilaris.
• 2.2. Hatching success for both species was highest at pH values above 4.5.
• 3.3. Survival capacities were significantly higher at 20°C over a pH range of 4.0-7.2.
• 4.4. Oxygen consumption rates increase as a function of increasing temperature and reduced acidity.
• 5.5. Loss of the nymphal righting response was observed at pH 3.5. This response can be used as a behavioral assay for acid stress.

     

Metabolism of ingested indole compounds in the gut of three species of heteroptera

• 1.1. All kinds of indole compounds used for the experiment were more or less metabolized in the gut of Dolycoris baccarum, Eurydema rugosum and Elasmostethus humeralis.
• 2.2. The metabolic pattern of the bugs was classified into four types (I–IV) for several indole compounds in the same way as for IAA.
• 3.3. The IAA metabolites in the excreta of the three species were probably the high-molecular compound combining with such substances as amino acids, sugars or proteins to some position of indole nucleus.
• 4.4. The crude excreta of E. humeralis fed with each of several indole compounds had a significant auxin activity.
• 5.5. Most of the metabolites of indole-3-acetaldehyde in the excreta of E. humeralis had also a significant auxin activity.
• 6.6. The significance of auxin metabolism in the gut of the bugs and the difference of auxin metabolism between aphids and bugs are discussed.

     

The fate of the bowman-birk trypsin inhibitor from soybeans in the digestive tract of chicks

• 1.1. Intestinal absorption of the Bowman-Birk trypsin inhibitor from soybeans was studied comparatively in chicks by direct follow-up of absorbed radioactive inhibitor and by radioimmunological estimation of the unlabelled inhibitor.
• 2.2. Initial studies, performed in vitro by the inverted sac technique, suggested that both the native inhibitor and its degradation products were absorbed.
• 3.3. However, the results obtained for in situ and in vivo experiments indicated that the absorption of the native inhibitor is negligible.
• 4.4. Most of the inhibitor is degraded during its passage through the intestine, and the majority of the degradation products is excreted in the feces.
• 5.5. The effects of ingested inhibitor on pancreas enlargement and on secretion of pancreatic enzymes stems from an indirect effect on the intestine.