Christ vs. Communism: Communism as a Religious Social Problem in Finland's Proto-Fascist Lapua Movement in the 1930s

This article traces the emergence of religious anti-communist discourse in Finland’s proto-fascist Lapua Movement in the 1930s. Applying constructionist social problems theory, it discusses the constructions of communism as a religious social problem, Christian piety as a solution to the problem of godless communism, and the religious legitimation of violence. The article argues that by identifying Christianity with the Finnish nation the construction of communism as a religious problem—itself an outcome of the influence of revivalist Lutheran ministers in the leadership of the movement—resonated with the broader audience, but that this indigenous religious nationalism lost support with the increasing belligerence of the movement

On the relation between ERG waves and retinal function : Inverted Rod photoresponses from the frog retina

In rod mass receptor photoresponses recorded across the isolated frog retina, a paradoxical cornea-positive wave may precede the response of normal polarity. We present a model which shows that the light-induced decrease in rod current can give rise to inverted or biphasic ERG signals if the distal part (tip) of the rod outer segment responds more slowly and/or less sensitively than the proximal part (base). The condition is that current entering at the tip is represented with greater weight in the ERG. The model reproduces recorded ERG waveforms well. It further predicts that if there is a light-in sensitive conductance in the tip membrane, ERG photoresponses may be non-recordable although current photoresponses are only slightly reduced. The model reveals a type of complexity in the relation between mass potentials and underlying physiological processes which has not previously received attention

Effects of sulfhydryl binding reagents on the photoresponses of amphibian retinal rods

1. 1. We have studied the effects of four sulfhydryl binding reagents (NEM, PHMB, PCMP and IAA) and the disulfide reducing agent, DTT, on the photocurrent of vertebrate rods by recording the ERG across the aspartate-treated retina of the frog, and by suction pipette recording from isolated rods of the tiger salamander. 2. 2. SH-reagents brought about three types of effects on rods: (1) a fast transitory increase in light sensitivity and photocurrent; (2) a “leakage” current that could not be turned off by light; and (3) a slower irreversible loss of sensitivity. 3. 3. The fast effects, including the leakage current, are attributable in part to direct action on the sodium channels in the plasma membrane. 4. 4. NEM, PHMB and PCMP were able to affect the transduction machinery inside the rod, which first contributed to the growth of photoresponses, but gradually depressed light sensitivity irreversibly. 5. 5. Typically, the reagents also induced large ERG transients of non-receptor (glial) origin. 6. 6. The fast effects of DTT on isolated rods were similar to those of the SH-reagents. This drug) however, had no clear effect on ERG photoresponses, suggesting that the oxidation of sodium-channel SH-groups is modest in the intact retina as compared with isolated rods

Transient sensitivity reduction and biphasic photoresponses observed when retinal rods are oxidized

1. 1. Rod photoresponses and the effects of oxidation have been studied by recording either the transretinal voltage in aspartate-treated retinas or the outer segment current of single rods. 2. 2. Oxidizing conditions transiently decreased, reducing conditions increased sensitivity. 3. 3. Biphasic photoresponses were seen when the level of oxidation was rising and also in some other sensitivity-depressing conditions. 4. 4. A model is proposed which explains the biphasic responses in terms of sensitivity differences between the tip and the base of the rod outer segment

Changes in the light-sensitive current of salamander rods upon manipulation of putative pH-regulating mechanisms in the inner and outer segment

The light-sensitive current of dark-adapted rods isolated from the Ambystoma retina was recorded while either the inner or the outer segment (IS or OS) protruding from the suction pipette was exposed to treatments intended to reveal the physiological roles of pH-regulating transport mechanisms. Applied to the IS, both amiloride (presumed to block Na+/H+ exchange, 2 mM) and 4-4′-diisothiocyanatostilbene-2, 2′-disulphonic acid (DIDS) (presumed to block bicarbonate transport, 0.1 mM) generally abolished light sensitivity completely but reversibly, consistent with acidification of the IS. Yet, the circulating (“dark”) current often persisted, implying that the OS was not acidified. Applied to the OS, amiloride depressed but DIDS increased the dark current and photoresponses. Given the fact that the current increases with rising OS-pHi, this suggests alkalinization, which could be due to DIDS inhibiting bicarbonate extrusion by HCO3−/Cl− exchangers in the OS. Consistent with this idea, replacing external Cl− by other anions increased the current as would be expected if HCO3−/Cl− exchange is reversed. We propose that the IS and OS manage their add balances independently and with different sets of transport mechanisms. Acidosis in either compartment suppresses the photosensitivity of the rod, but by differing mechanisms

Changes in retinal time scale under background light : observations on rods and ganglion cells in the frog retina

The kinetics of rod responses to flashes and steps of light was studied as a function of background intensity (IB) at the photoreceptor and ganglion cell levels in the frog retina. Responses of the rod photoreceptors were recorded intracellularly in the eyecup and as ERG mass potentials across the isolated, aspartate-superfused retina. The kinetics of the retinally transmitted signal was derived from the latencies of ganglion cell spike discharges recorded extracellularly in the eyecup. In all states of adaptation the linear-range rod response to dim flashes could be modelled as the impulse response of a chain of low-pass filters with the same number of stages: 4 (ERG) or 4–6 (intracellular). Dark-adapted time-to-peak (tp, mean ± SD) at 12°C was 2.4 ± 0.6 sec (ERG) or 1.7 ± 0.4 sec (intracellular). Under background light, the time scale shortened as a power function of background intensity, IB−b with b = 0.19±0.03 (ERG) or 0.14±0.04 (intracellular). The latency-derived time scale of the rod-driven signal at the ganglion cell agreed well with that of the photoreceptor responses. The apparent underlying impulse response had tp = 2.0±0.7 sec in darkness and accelerated as IB−b with b = 0.17±0.03. The photoreceptor-to-ganglion-cell transmission delay shortened by 30% between darkness and a background delivering ca 104 photoisomerizations per rod per second. Data from the literature suggest that all vertebrate photoreceptors may accelerate according to similar power functions of adapting intensity, with exponents in the range 0.1–0.2. It is noteworthy that the time scale of human (foveal) vision in experiments on flicker sensitivity and temporal summation shortens as a power function of mean luminance with b ≈ 0.15

pH regulation in frog cones studied by mass receptor photoresponses from the isolated retina

Mass cone photoresponses were recorded across the aspartate-treated frog retina under treatments chosen to affect putative pH-regulating mechanisms. The saturated response amplitude (Umax) was found to be a monotonically increasing function of perfusion pH in the range 7–8, and thus presumably of intracellular pH (pHi). Accepting that Umax can be used as an index of pH, changes, two results indicate the importance of bicarbonate transport for preventing intracellular acidification: (1) bicarbonate-buffered (6 mM HCO3− + 6 mM HEPES) perfusate increased Umax compared with nominally bicarbonate-free perfusate (12 mM HEPES); (2) the anion transport blocker DIDS (0.1 mM) caused a strong decrease in the amplitude of photoresponses. Substitution of 95 mM chloride by gluconate in the perfusing fluid boosted photoresponses indicating that at least part of the bicarbonate transport involves HCO3−/Cl− exchange. Amiloride (2mM) also caused a decrease of photoresponse amplitude, which suggests that Na+/H+ exchange contributes to pHi regulation. In all these respects, cones behaved similarly to rods. Cones differed from rods (in the intact retina) in that addition of 0.5 mM of the carbonic anhydrase inhibitor acetazolamide reduced (never augmented) photoresponses. The difference is considered in relation to the presence of carbonic anhydrase in cone, as opposed to rod, outer segments

Light responses and light adaptation in rat retinal rods at different temperatures

Rod responses to brief pulses of light were recorded as electroretinogram (ERG) mass potentials across isolated, aspartate-superfused rat retinas at different temperatures and intensities of steady background light. The objective was to clarify to what extent differences in sensitivity, response kineticsandlight adaptationbetweenmammalianandamphibianrods can be explained by temperature and outer-segment size without assuming functional differences in the phototransduction molecules. Corresponding information for amphibian rods from the literature was supplemented by new recordings from toad retina. All light intensities were expressed as photoisomerizations per rod (Rh∗). In the rat retina, an estimated34%of incident photons at the wavelength of peak sensitivity caused isomerizations in rods, as the (hexagonally packed) outer segments measured 1.7 μm×22 μm and had specific absorbance of 0.016 μm−1 on average. Fractional sensitivity (S) in darkness increased with cooling in a similar manner in rat and toad rods, but the rat function as a whole was displaced to a ca 0.7 log unit higher sensitivity level. This difference can be fully explained by the smaller dimensions of rat rod outer segments, since the same rate of phosphodiesterase (PDE) activation by activated rhodopsin will produce a faster drop in cGMP concentration, hence a larger response in rat than in toad. In the range 15–25◦C, the waveformand absolute time scale of dark-adapted dim-flash photoresponses at any given temperature were similar in rat and toad, although the overall temperature dependence of the time to peak (tp) was somewhat steeper in rat (Q10 ≈ 4 versus 2–3). Light adaptation was similar in rat and amphibian rods when measured at the same temperature. The mean background intensity that depressed S by 1 log unit at 12◦C was in the range 20–50 Rh∗ s−1 in both, compared with ca 4500 Rh∗ s−1 in rat rods at 36◦C. We conclude that it is not necessary to assume major differences in the functional properties of the phototransduction molecules to account for the differences in response properties of mammalian and amphibian rods

Rod phototransduction modulated by bicarbonate in the frog retina : roles of carbonic anhydrase and bicarbonate exchange

1. Effects on rod phototransduction following manipulation of retinal CO2-HCO3- and H+ fluxes were studied in dark-adapted retinas of the frog and the tiger salamander. 2. Rod photoresponses to brief flashes of light were recorded from the isolated sensory retina as electroretinogram mass receptor potentials and from isolated rods by the suction-pipette technique. The experimental treatments were: (1) varying [CO2] + [HCO3-] in the perfusion fluid: (2) applying acetazolamide (AAA), which inhibits the enzyme carbonic anhydrase (CA); and (3) applying 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS) which blocks exchange mechanisms transporting HCO3- across cell membranes. 3. The concentration of the internal transmitter of the rods, cyclic GMP, was biochemically determined from the rod outer segment layer of retinas that had been incubated in the same solutions as were used for perfusion in the electrophysiological experiments. 4. The introduction of 6 mM-sodium bicarbonate to replace half the buffer of a nominally CO2-HCO3(-)-free (12 mM-phosphate or HEPES, [Na+] constant) Ringer solution doubled the cyclic GMP concentration in the rod outer segment layer and increased the saturating response amplitude and the relative sensitivity of rods in the intact retina. 5. The introduction of 0.5 mM-AAA into bicarbonate-containing Ringer solution accelerated the growth of saturated responses and sensitivity. Incubation of the retina in AAA-bicarbonate Ringer solution elevated the concentration of cyclic GMP ninefold compared with the phosphate control. 6. No effects of switching to bicarbonate-AAA Ringer solution were observed in the photocurrent of isolated rods drawn into suction pipettes with only the outer segment protruding into the perfusion fluid. The target of AAA is probably the CA-containing Muller cell. 7. The introduction of DIDS into the perfusate (at normal pH 7.5) set off a continuous decay of photoresponses which finally abolished light sensitivity completely. The decay proceeded regardless of whether bicarbonate and AAA were present or not. 8. Rods that had lost their photosensitivity in DIDS recovered almost fully when the pH of the DIDS perfusate was raised to 8.5. They also recovered when DIDS was washed out with bicarbonate Ringer solution at constant pH (7.5). 9. It is proposed that all our treatments ultimately modulate the intracellular pH of the rods which is determined by the relative rates of H+ leakage and HCO3- transport into the cells.(ABSTRACT TRUNCATED AT 400 WORDS