Leptin and adiponectin have opposite effect on ciliary activity, calcium wave velocity and ovum transport velocity in the rat oviduct

1. In forward-swimming Paramecium the direction of metachronal wave propagation is turned progressively clockwise from forward-right to backward-left if the viscosity of the medium is increased to more than 100 cP. 2. With increasing viscosity the direction of the power stroke is turned clockwise at a lower rate than the direction of waves. This leads to a gradual transformation of the dexioplectic metachrony toward a symplectic pattern. 3. As viscosity is raised the polarization of the ciliary cycle in time and space is Progressively reduced, so that the beat becomes increasingly helicoidal. 4. Metachronal coordination gradually breaks down at viscosities of more than about 100 cP, but is retained better at the anterior end of the cell than in more posterior regions. 5. At viscosities above 12 cP the left-handed swimming helix of Paramecium is changed into a right-handed helix. This is produced primarily by the viscositydependent clockwise shift in the direction of the power stroke from backward-right to backward-left. 6. The frequency of peristomal cilia (32/s. at 20°C) decreases with rising viscosity. Under constant conditions, a posteriorly directed gradient of decreasing frequency can be observed with the stroboscope. 7. Raising the viscosity leads to an increase of the average wavelength from 10.7 µm at 1 cP to 14.3 µm at 40 cP. In the same range of viscosity the wave velocity, which is the product of frequency and wavelength, is reduced from 340 to 200 µm/s, since the drop in frequency exceeds the increase in wavelength. 8. The wave velocity tends to be stabilized by reciprocal relations between frequency and wavelength, if all other factors are kept constant. However, the wavelength is found to be different in forward-swimming and backward-swimming animals at 40 cP without a change in frequency (14.1 bps; 14.3 compared to 12.7 µm). This is explained if the metachronal wavelength is increased by decreasing polarization of the ciliary cycle. 9. A working hypothesis is put forward which explains the origin of a metachronal system by the distribution of forces parallel to the cell surface produced by polarized or unpolarized cycles of ciliary movement.

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Further Observations on Co-Ordination and the Determination of Frequency in the Peristomial Cilia of Stentor

Journal of Experimental Biology ◽

10.1242/jeb.34.1.106 ◽

1957 ◽

Vol 34 (1) ◽

pp. 106-115

Author(s):

M. A. SLEIGH

Keyword(s):

Cardiac Muscle ◽

Wave Velocity ◽

Main Part ◽

Beat Frequency ◽

The Other ◽

Ciliary Activity ◽

Transmission Properties ◽

Excitatory State ◽

Nerve Synapse

1. The work described is a continuation of the work on the peristomial cilia of Stentor previously reported (Sleigh, 1956). The same methods were used in making the observations. 2. A cut across the peristome row of cilia did not affect the wave velocity, but the frequency distal to the cut was usually altered. In twenty-two cases the distal frequency was decreased, and in seven cases it was increased. 3. Cilia in the gullet region are smaller and closer together than those in the main part of the row; these cilia show the same frequency as the other cilia, but a smaller wavelength and wave velocity. The number of cilia in every metachronal wave of the row is the same, as is the number of cilia stimulated in unit time by a single metachronal impulse in any part of the row. 4. The wave velocity is dependent on the number of cilia through which the conduction is passed. The transmission is thought to be the result of a rapid conduction process between the cilium bases and a slower build-up of an excitatory state in the cilium. 5. The frequency of a group of cilia is dependent upon the activity of a pacemaker at the beginning of the group; this pacemaker is probably a cilium with a suitable rate of beat. Frequency is limited by the rate of stimulation or the rate of contraction, whichever is the slower. 6. It is suggested that there are some five excitation stages in the excitation of each cilium, and that each stage takes about 1 msec.; this is comparable with the delay at a nerve synapse. 7. The results of these experiments and observations on ciliary activity indicate that the pacemaker and transmission properties of ciliated tissues and cardiac muscle are comparable in many respects.

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Metachronism and Frequency of Beat in the Peristomial Cilia of Stentor

Journal of Experimental Biology ◽

10.1242/jeb.33.1.15 ◽

1956 ◽

Vol 33 (1) ◽

pp. 15-28 ◽

Cited By ~ 1

Author(s):

M. A. SLEIGH

Keyword(s):

Wave Velocity ◽

Magnesium Chloride ◽

Wave Length ◽

Methyl Cellulose ◽

Aluminium Chloride ◽

Ciliary Activity ◽

Metachronal Wave ◽

Low Concentrations ◽

Two Factors ◽

Significant Change

1. A stroboscopic method was used to determine the frequency of beat of the peristomial cilia of Stentor polymorphus (Ehrbg.). The metachronal wave-length was measured from photographs. These two values were used to calculate the rate of propagation of the metachronal wave. 2. The Arrhenius temperature characteristics for frequency and for wave velocity were calculated for the temperature range from o to 25° C. The average values found, 11,350 and 7520, were significantly different for the two factors. 3. An increase in the viscosity of the medium by addition of methyl cellulose caused a decrease in frequency, but no significant change in wave velocity. 4. The presence of magnesium chloride in low concentrations caused an increase in frequency, but no significant change in wave velocity. Aluminium chloride caused similar increases in frequency at lower concentrations than magnesium chloride. 5. The drug digitoxin had different quantitative and qualitative effects on the frequency and on the wave velocity. Small increases in frequency occurred over the concentration range in which large increases in wave velocity were recorded. The wave velocity increase reached a maximum at about 0.4 mg./l. of digitoxin and was some six times as great as the frequency increase at this concentration. 6. It is concluded that the mechanical process involved in ciliary activity functions independently of the co-ordination process. A combination of these two factors determines the magnitude of the metachronal wave-length.

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The Effect of Exogenous Fluoride on the Calcium PUMP, Ciliary Activity, and Shell Formation of the Fingernail Clam, Musculium Transversum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053097 ◽

1982 ◽

Vol 40 ◽

pp. 58-59

Author(s):

Anthony Paparo ◽

Judy A. Murphy ◽

Robert Dean

Keyword(s):

Mississippi River ◽

Calcium Pump ◽

Bottom Fauna ◽

Ciliary Activity ◽

Shell Formation ◽

Middle Reach ◽

Shell Matrix ◽

Fingernail Clams ◽

Ca Carbonate

In the mid-1950's, fingernail clams virtually disappeared from a 100-mile section of the IL River, a tributary of the Mississippi River, due to unknown causes. A survey of the bottom fauna of the IL River in 1979, revealed that the clams were still absent from the middle reach of the River, where they had been abundant prior to the die-off in the 1950's. Some factor(s) in the River currently prevent the clams from recolonizing areas where they were formerly abundant. Recently, clams exposed to fluoride developed abnormal grooves in the shell matrix. Fluorides are known to be protoplasmic poisons removing essential body calcium by precipitation. Since the shell consists primarily of Ca carbonate, this investigation examines the possible role of fluoride on shell formation and the poisoning of the Ca pump which can directly inhibit lateral ciliary activity on the gill.

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The Red Neuronal Pigment in the Nervous System of the Mussel, Mytilus Edulis: Localization and Its Effect on Lateral Ciliary Activity with Spectral and Analytical Changes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098952 ◽

1981 ◽

Vol 39 ◽

pp. 494-495

Author(s):

Anthony A. Paparo ◽

Judith A. Murphy

Keyword(s):

Nervous System ◽

Mytilus Edulis ◽

Neuronal Cell ◽

Ciliary Activity ◽

Neuronal Cell Bodies ◽

The Central Nervous System ◽

Intracellular Organelles ◽

The Common ◽

The Individual ◽

Cryostat Sections

The purpose of this study was to localize the red neuronal pigment in Mytilus edulis and examine its role in the control of lateral ciliary activity in the gill. The visceral ganglia (Vg) in the central nervous system show an over al red pigmentation. Most red pigments examined in squash preps and cryostat sec tions were localized in the neuronal cell bodies and proximal axon regions. Unstained cryostat sections showed highly localized patches of this pigment scattered throughout the cells in the form of dense granular masses about 5-7 um in diameter, with the individual granules ranging from 0.6-1.3 um in diame ter. Tissue stained with Gomori's method for Fe showed bright blue granular masses of about the same size and structure as previously seen in unstained cryostat sections.Thick section microanalysis (Fig.l) confirmed both the localization and presence of Fe in the nerve cell. These nerve cells of the Vg share with other pigmented photosensitive cells the common cytostructural feature of localization of absorbing molecules in intracellular organelles where they are tightly ordered in fine substructures.

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