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1.
1.  Monopolar cells of the first visual ganglion, the lamina, of the bee were recorded from and stained intracellularly.
2.  Several different response types to pulses of spectral light were found. The most common response type hyperpolarized in a phasic-tonic fashion. The tonic hyperpolarizing response frequently decreased gradually, but in some cases increased with lasting illumination. Some cells also gave a transient response to light-OFF. In contrast, one stained and several unstained cells showed depolarizing responses. Five cells exhibited spiking responses under normal physiological conditions.
3.  The V/log I-functions were steeper than those of the photoreceptors and, in some cases, had both rising and falling parts with increasing intensities. The spectral sensitivity obtained with the constant response method showed a peak in the green (510–535 nm) in most cells. A series of spectral flashes revealed an additional type with highest sensitivity in UV. Indirect evidence was found in one cell for spectral opponent processing.
4.  Two morphological types of monopolar cells were stained. These correspond well to Ribi's (1976) L1 and L2 cells, with some differences in detail. The most frequently stained cell type closely resembles his L2 type. All 3 stained spiking cells were of this type.
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2.
1.  The larva of the tiger beetle (Cicindela chinensis) possesses six stemmata on either side of the head. Optical and physiological properties of two pairs of large stemmata and a pair of anterior medium sized stemmata, and responses of second-order visual interneurons (medulla neurons) have been examined.
2.  Objects at infinite distance were estimated to focus 50 m deep in the retina in the large stemmata. Receptive fields of four large stemmata, the acceptance angle of each being 90°, largely overlapped one another.
3.  The stemmata possessed a single type of retinular cell with a maximal spectral sensitivity at 525 nm, and a flicker fusion frequency of 25–50 Hz.
4.  Medulla neurons expanded fan-shaped dendrites in the medulla neuropil, and their axons extended into the protocerebrum. They responded to illumination with a variety of discharge patterns. They also responded with spike discharges to moving objects and to apparent movements provided by sequential illumination or extinction of LEDs. They did not show directional selectivity. They possessed well-defined receptive fields ranging from 30° to 105°.
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3.
1.  We examined the retinas of 2 species of stomatopods in the superfamily Squilloidea, Cloridopsis dubia and Squilla empusa, and 2 species of the super-family Lysiosquilloidea, Coronis scolopendra and Lysiosquilla sulcata, using microspectrophotometry in the visible region of the spectrum.
2.  Retinas of all species included numerous photostable pigments, such as green reflecting pigment, hemocyanin, colored oil droplets, and vesicles. Both lysiosquilloid species also had intrarhabdomal filters within specialized photoreceptors of the midband.
3.  Squilloid species contained a single visual pigment throughout all photoreceptors, with peak absorption at medium wavelengths (near 515nm). Retinas of lysiosquilloids contained a diversity of visual pigments, with estimated max values ranging from 397 to 551 nm.
4.  Spectral sensitivity functions were estimated for the lysiosquilloid species based on estimates of visual pigment nax, photoreceptor dimensions, and specific absorbances of the visual pigments and intrarhabdomal filters. Ommatidia of midband Rows 1 to 4 contained pairs of narrowly tuned spectral receptors, appropriate for spectral discrimination, while ommatidia of midband Rows 5 and 6, and all peripheral ommatidia, had broad spectral sensitivity functions.
5.  Lysiosquilloid stomatopods have retinas that closely resemble those of gonodactyloids both structurally and in their visual pigment diversity. In contrast, squilloids have retinas that are much simpler. These differences appear to be related to the habitats and activity cycles of species belonging to the 3 major superfamilies of stomatopod crustaceans.
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4.
1.  Spectral-sensitivity functions of large-field movement-detecting units in the lobula plate of the dronefly Eristalis tenax L., which is a Batesian mimic of the honeybee, were measured using visual stimuli consisting of light flashes, or moving gratings. Two classes of units were studied, one class responding to inward horizontal motion in the contralateral eye (presumably the homologue of the well-known HI in other fly species), and the other class responding to vertically-down-ward motion in the contralateral eye.
2.  In both classes of units, the spectral-sensitivity function of the response to flashes is characterized by two peaks, one in the UV at ca. 350 nm and the other in the blue at ca. 475 nm (Figs. 3, 8). It resembles the spectral-sensitivity function of the R1-R6 class of receptors in other flies.
3.  In both classes of units, the spectral-sensitivity function of the response to movement is characterized by a single peak, occurring in the blue at ca. 450 nm (Figs. 7, 9).
4.  Control experiments on homologous units in the Australian Sheep Blowfly Lucilia cuprina, using identical stimulating conditions reveal that the response to flashes as well as movement possesses a dual-peaked spectral sensitivity, with one peak in the UV and the other in the blue-green region of the spectrum (Figs. 10–12).
5.  The results indicate that the pathways subserving the inputs to movement-detecting neurons in Eristalis are driven by more than one spectral class of photoreceptors. They also reveal that the spectral sensitivity of movement detection in Eristalis bears a closer resemblance to that of the honeybee, than to that of other flies. This similarity to the honeybee may arise from the fact that the dronefly and the honeybee occupy similar ecological niches, both foraging for nectar in flowers.
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5.
1.  Tethered crickets (Gryllus campestris) walking on an air-suspended ball exhibit a spontaneous response to thee-vector of polarized light presented from above. In this study we determined the spectral sensitivity of polarization vision by finding the threshold light intensities for eliciting thise-vector response at different wavelengths.
2.  The behaviorally determined spectral sensitivity was compared with the spectral sensitivity of the three spectral receptor types of the cricket eye (UV, blue, green) as measured electrophysiologically. The best match was obtained with the blue-receptor. This supports the thesis that polarization vision in crickets is mediated by the anatomically and physiologically specialized dorsal rim area of the eye. This part of the eye contains only blue-receptors, whereas other eye regions consist of UV- and green-receptors.
3.  The absolute sensitivity of the cricket'se-vector detection system is very high. The threshold irradiance (at 50% of the maximal response) at 433 nmis 2.5×107 quanta cm–2 s–1, which is even lower than the effective quantum flux (range 380–500 nm) under the clear, moonless night sky.
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6.
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7.
1.  The ommatidia of the butterfly Papilio have a fused and tiered rhabdom. The distal tier of the rhabdom is made up of four distal photoreceptors (R1–4), whereas the proximal tier is made up of four proximal (R5–8) and one basal photoreceptor cell (R9).
2.  We first confirmed by light microscopy that the ommatidia of Papilio are not twisted, i.e. have the same spatial organization all about the longitudinal axis. The polarization method, previously applied to the distal tier, hence is applicable to identify the photoreceptor location from the peak angle of the polarization sensitivity.
3.  We determined the polarization and spectral sensitivity of in total 109 proximal and basal photoreceptors in the lateral looking eye region. All of the photoreceptors were either green or red type, most of which fall into three classes as judged by the peak angles of the polarization sensitivity: around 40°, 150°, and 180° (= 0°) with respect to the dorso-ventral axis. The first two classes are formed by the proximal photoreceptors with straight microvilli oriented at the average angle of 39° (R6, 8) and 144° (R5, 7) respectively, and the third is formed by the basal photoreceptors R9 with straight microvilli oriented at 180° (= 0°). The mean polarization sensitivity (PS = maximal sensitivity/minimal sensitivity) was about 2.
4.  75% of the proximal and 48% of the basal photoreceptors were of the red type.
5.  A single ommatidium of Papilio appears to contain two to four types of spectral receptors.
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8.
1.  Paramecium bursaria was stimulated by a light spot of 10–15 m diameter, and the photosensitive site was searched by recording responses in swimming behavior and in membrane potential.
2.  Local stimulation to the anterior half of the cell caused an avoiding response.
3.  Stimulation to the cells deciliated by ethanol treatment elicited a depolarization of the membrane potential.
4.  Local stimulation to the anteroventral portion elicited a depolarization, but stimulation to the dorsal side induced no change in the membrane potential.
5.  The action spectrum of depolarization elicited by local stimulation to the anteroventral surface showed two main peaks at 420 nm and 560 nm, corresponding to those of light stimulation of the whole cell.
6.  It is concluded that a photosensitive site exists on the anteroventral surface ofParamecium, in particular within the oral groove of the cell. This local photosensitivity is discussed with respect to the mating reaction.
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9.
1.  Up to 9 kHz, the tympanal membrane of the grasshopper Chorthippus biguttulus responds with equal sensitivity at the attachment sites of the low and the high-frequency receptors; at the latter site it is also particularly sensitive between 10 and 20 kHz.
2.  The frequency spectra of the songs of both sexes exhibit maxima at 7–8 kHz, to which the membrane is well matched. In the high-frequency region, where the male songs have a peak at 30 kHz, there is no corresponding maximum in the membrane oscillation.
3.  Because the tympanal membrane is immediately adjacent to air sacs in the tracheal system, it is deflected inward and outward by as much as 80 m during the respiratory cycle.
4.  Measurements by laser vibrometry show that acoustically induced membrane oscillations are attenuated severely due to the respiratory displacement of the membrane for frequencies up to 10–12 kHz. By contrast, at higher frequencies the membrane sensitivity is doubled or tripled.
5.  As a result of these membrane effects, the discharge in the tympanal nerve was profoundly reduced in the low-frequency range, whereas above 11 kHz there was a marked increase. This modulation of auditory sensitivity affects the animals' ability to detect conspecific songs.
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10.
1.  Some units in the lateral ocellar nerves of the locust,Locusta migratoria, are influenced transsynaptically by the activity of ascending fibres in the thoracic connectives and therefore may be efferent to the afferent ocellar system.
2.  A variety of sensory inputs excite the ocellar nerve units, including illumination of the compound eyes, active and passive movement of the wings, wind stimuli to the thorax and sound.
3.  Most ocellar interneurons are influenced transsynaptically by electrical stimulation of the cervical connectives. L-neurons are depolarized and the components of their response to a rectangular light pulse are changed in amplitude. Only a few S-neurons could be examined. All of them were excited directly or indirectly.
4.  The descending ocellar interneurons (DN's) are influenced by stimulation of the contralateral connective, perhaps via efference to the ocellus or to ocellar L-cells.
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11.
The present review describes the effects of light on reproductive processes in fungi, mainly when action spectra are available.The study of these has resulted in three kinds of photoresponses observable in fungi:
–  responses only to UV light (230–380 nm)
–  responses to NUV and blue light (300–520nm)
–  responses to great wavelengths of the visible spectrum. The photomorphogenetic processes on the control of these same photoreceptor pigments are reviewed.
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12.
The circadian rhythm in the ERG amplitude of the lateral compound eye ofLimulus can be phase shifted either by general illumination or by illuminating combinations of the photoreceptor organs.
1.  For 15-min exposures, light confined to one lateral eye, or to the median ocelli, or to the ventral photoreceptor region resulted in the smallest phase shifts.
2.  Illuminating combinations of these organs produced larger shifts. The most effective combination tested included the median ocelli, the ventral photoreceptors, and one lateral eye. The phase shift resulting from illumination of this combination was only about one-half of the shift produced by general illumination.
3.  These results suggest that the circadian clock also receives light information from other, unidentified, photoreceptors located outside the prosoma.
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13.
The caudal photoreceptors (CPRs) of crayfish (Procambarus clarkii) can trigger walking and abdominal movements by their response to light.
1.  In a restrained, inverted crayfish, illumination of A6 evoked a CPR discharge followed by leg movements and bursting from the abdominal tonic flexor (TF) motoneurons. Intracellular electrical stimulation of a single CPR at high frequency (80 Hz) evoked similar responses.
2.  Responses only occurred when a single CPR axon was driven at 60 Hz or more and outlasted the stimulus.
3.  CPR stimulation also excites the pattern-initiating network (Moore and Larimer 1987) in the abdomen.
4.  The axon of the CPR projects from ganglion A6 to the brain. Terminal branches occur in the subesophageal ganglion and the brain. A small descending interneuron is dye-coupled to CPR in the subesophageal ganglion.
5.  In animals with cut circumesophageal connectives, the CPRs can evoke walking and the abdominal motor pattern.
6.  The relationship of the abdominal motor pattern to walking is altered by restraint and/or inversion. In freely moving crayfish, the cyclic abdominal motor pattern is only observed with backward walking. In restrained, inverted crayfish, the motor pattern occurs with both forward or backward walking.
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14.
1.  We examined microspectrophotometrically the retinas of 3 species of stomatopods in the superfamily Gonodactyloidea, all of which live in environments that are reduced both in the intensity and spectral range of natural illumination. Species examined were Odontodactylus brevirostris, O. scyllarus, and Hemisquilla ensigera.
2.  All 3 species had the typical gonodactyloid diversity of visual pigments, with 8 different photopigments residing in the 4 tiered rows of the midband and 2 additional types in the untiered classes of photoreceptors in the midband and peripheral retina. The spectral range covered by the max values of the visual pigments of each species was similar to that of other gonodactyloid and lysiosquilloid species.
3.  Apparent retinal adaptations in species of Odontodactylus for vision in dimly lit, spectrally narrow photic environments were seen primarily as specializations of the intrarhabdomal filters. These were of reduced diversity, and had reduced absorption at long wavelengths compared to the filters of other gonodactyloid stomatopods. Retinas of H. ensigera lacked both proximal classes of intrarhabdomal filter, and had the smallest total range of visual pigment max yet observed in mantis shrimps. These modifications decrease the spectral range and number of types of narrow-band spectral classes of phooreceptors, while increasing their sensitivity.
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15.
1.  Properties of the membrane currents ofDidinium nasutum have been investigated under voltage clamp in different solutions and after deciliation.
2.  Theearly transient Ca2+ inward current activates in a voltage-dependent manner. Inactivation is both Ca2+ -dependent and voltage-dependent.
3.  Alate Ca2+ current rises with time to peak > 50 ms and decays in the order of seconds.
4.  Activation and inactivation of the late Ca2+ current is voltage-dependent.
5.  The delayed outward current is activated by voltage. The kinetics of this K+ current, but not its amplitude, are enhanced in the presence of intracellular EGTA.
6.  The two voltage-dependent Ca2+ channels are located in the cilia, whereas all K+ channels are restricted to the somatic membrane.
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16.
1.  Underwater downwelling quantal irradiance spectra were measured in estuarine and coastal areas under various tidal and rainfall conditions. At midday the available spectrum near the bottom has maximal irradiance in the region of about 570 to 700 nm in the estuary, whereas in offshore coastal areas greatest irradiance occurs between 500 and 570 nm. At twilight in an estuary, maximal underwater downwelling irradiance shifts to the 490–520 nm region.
2.  The visual pigment absorption maxima of 27 species of benthic crustaceans from semi-terrestrial, estuarine and coastal areas have values ranging from 483 to 516 nm. There is no obvious shift in the max from long wavelengths in estuarine species to shorter wavelengths in coastal species. The only match between max and midday spectrum was for a continental shelf species,Geryon quinquedens.
3.  The Sensitivity Hypothesis is predicted to account for the visual sensitivity of benthic crabs from estuarine and coastal areas. To assess the match between visual spectral sensitivity and environmental spectra, photon capture effectiveness was calculated for a range of idealized visual pigment absorption functions operating in the measured environmental spectra.
4.  All crab species are poorly adapted for maximal photon capture at midday, since pigments having max longer than 540 nm function best under all daytime spectral conditions. Photon capture of visual pigments with max near 500 nm improves dramatically at twilight, particularly at lower visual pigment densities and shallow depths. However, pigments having max at wavelengths longer than those for the crabs are equally or more efficient at photon capture. Therefore the Sensitivity Hypothesis is not supported for crustaceans.
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17.
1.  The reactions of tympanic nerve fibers ofLocusta migratoria were recorded by glass microelectrodes in the metathoracic ganglion.
2.  The units were classified by frequency-, intensity-, and directional characteristics as well as by their response pattern. The response to speciesspecific song is compared with the response to song ofEphippiger ephippiger.
3.  The physiological properties lead to a classification into three types of low-frequency neurons (characteristic frequency 3.5–4 kHz; 4kHz; 5.5–6 kHz) and one type of high-frequency neuron (12–20 kHz). This is similar to other species (Gray, 1960, Michelsen, 1971).
4.  Intensity-coding is done by sharp rising intensity characteristics and by different absolute thresholds of the units.
5.  There is a marked directional sensitivity with some differences between LF and HF units. In the low frequency range the tympanal organ seems to react as a pressure gradient receiver; for high frequencies another mechanism is discussed.
6.  No filtering of species-specific song takes place at the level of the receptor cells.
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18.
1.  The spectral sensitivities of the photoreceptors in the compound eye of the stingless bee, Melipona quadrifasciata (Hymenoptera, Apoidea), was determined by the spectral scanning method. Three spectral receptor types were found with max at 356 nm, 424 nm, and 532 nm (Fig. 1). Intracellular markings confirmed one morphological type of green receptor (svf 1) and one type of UV receptor (1vf 1) whose axon morphology resembles that of the corresponding spectral receptor types in the honeybee, Apis mellifera (Fig. 2).
2.  Training experiments with a large number of color signals were performed at the hive entrance and the feeding place under natural daylight conditions (Figs. 4–6). The tests were either dual (2 alternative color signals) choice tests or multiple (12 simultaneously presented alternative color signals) choice tests. Melipona discriminates colors very well in both behavioral contexts, but discrimination is generally better at the feeding place (Fig. 7). A comparison with Apis shows that Melipona discriminates colors in the bluish green better than Apis, and that Apis discriminates all other colors better.
3.  The spectral properties of the receptor types were used to construct a color space in which all the color signals tested in the behavioral experiments are represented at particular loci (Fig. 3). A receptor model of color vision as proposed by Backhaus and Menzel (1987) for the honeybee is used to calculate the perceptual distance between the colors corresponding to the loci of the color stimuli. This model interprets the perceptual distance between two color stimuli as the number of just noticeable difference steps in the corresponding receptor voltage signals. The predicted distances are highly correlated with the discrimination values of the behavioral tests (Fig. 12).
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19.
With the aim of clarifying the role of screening pigments in photoreceptor optics of the compound eye, a comparative study of the optical properties of the honeybee eye in the visible region of the spectrum was carried out using wild-type bees and eye colour mutantssnow, snow laranja, ivoryumberandchartreuse with total or partial blockage of the tryptophane-ommochrome pathway.
1.  The electroretinogram (ERG) of mutant eyes displayed a sharp on-peak, this component being absent from normal heterozygote eyes (Fig. 6).
2.  The ERG of newly emerged bees (a) lacked the above on-peak and showed oscillations in mutants, and (b) lacked the off-peak which always occurs in the ERG of adults in all the genotypes studied when stimulated by visible light.
3.  The resting potentials of the receptor and cone cells were not found to be affected by mutations la, and the receptor potential ins/s ands la/slaphotoreceptors appeared to be similar to that in +/+
4.  Analysis of the amplitude characteristics of the whole eye of eight genotypes showed that the relative numbers of photons absorbed from an extended light source (4.5°×16.5°) and needed to elicit a standard ERG amplitude of 1 mV were as follows:s/si u/iusla/slach1/ch1(+/+; s/+ iu/+; sla/+)=14.38.612.2(100–250). These ratios are believed to reflect the progress in ommochrome formation in these strains.
5.  Spectral sensitivity curves (SSC) were obtained using an automatic spectrosensitometer and a spectral scan method which gave accurate results. The SSC of the whole eye in+/+ peaked at a max of 543±7 nm (SD,n=6), whereas max ins/s ands la/slashifted to 528±6 nm (n=9) and 548 ±3nm (n=6) respectively. The SSC ins/+ was the same as that in+/+. The bandwidth (width at 50% of peak sensitivity) of the SSC proved to be similar in+/+ ands/+ (126±10 nm and 128±8 nm), although ins/s the SSC appeared to be significantly narrower (106±7 nm;P<0.01; fig.=" 8,=" table=" 2).=">
6.  The peak spectral sensitivity of long-wave (LW) receptors lay at 541±5 nm (SD,n=14) in+/+ and at 526±5 nm (n=13) ins/s; the spectral distributions of the peaks in these genotypes were different. The bandwidth of the SSCs of the photoreceptors were 109±11 nm in+/+ and 103±4 nm ins/s, the difference being insignificant (Fig. 8, Table 2). The SSCs ins/s fit the absorption spectrum of pigment 526 (P 526) rather well whereas those in+/+ are noticeably distorted. The same is true for the whole-eye data.
7.  A theory is advanced to account for the acceptance functions of the photoreceptors of eyes with imperfect pigmentation. Light scattering in imperfectly screened eyes was estimated using a factor which the termed we parasitic absorption coefficientp (see Theory).
8.  The acceptance functions of LW photoreceptors were measured by three methods, and the results were similar to those predicted from the theory. On this basis the coefficientp was estimated; fors/s photoreceptors it lay between 0.65 and 0.76 according to experiments with a point light source (method 1), and was as great as 2.5 according to measurements with an extended light source (method 2). The latter technique, an integral method, made it possible to detect light scattering in normal bee eye, the coefficientp reaching 0.02 (Fig. 1, Table 3).
9.  In genotypes+/+ ands la/slathe absorption spectra of screening pigments were recorded by microspectrophotometry (MSP), and greater transmission of red light than blue-green was found (Fig. 11).
10.  Taking into account the screening effect of ommochromes, it is suggested that the visual pigment of LW photoreceptors in the honeybee eye is P 526; the absorption spectrum of this is highly similar to the SSC of LW photoreceptors in thes/s eye.
11.  On the basis of our theory and experimental results, the contrast transfer function (CTF) for the white honeybee eye was estimated to be only 0.1 (for white and black patterns with the spatial wavelength sp, the acceptance angle). Thus, the absence of screening pigments from the compound eye ofsnow mutants causes the great decrease in image contrast, and this serious sensory defect may be responsible for the fact that these mutants fail to find their way home.
Dedicated to Professor H. Autrum on the occasion of his 80th birthday  相似文献   

20.
1.  The effect of outward and inward water flows through the membrane on outward potassium currents of dialyzedHelix pomatia neurons was studied.
2.  An outward water flow increased the peak and sustained outward potassium currents and accelerated the kinetics of their activation. An inward water flow had quite opposite effects—it decreased the peak and sustained potassium currents and delayed the kinetics of their activation.
3.  The analysis of the effect of water flow on the conductance of potassium channels showed that an outward water flow increased both the potassium conductance at a given potential (gk) and the maximum potassium conductance (g k max ). An inward water flow again had the opposite effect—it decreased the potassium conductance at given potential and the maximum potassium conductance.
4.  Neither an outward nor an inward water flow significantly affected the fraction of open potassium channels at a given potential [n (V)].
5.  These data suggest that in dialyzed neurons the changes of outward potassium current during water flow through the membrane are due mainly to the changes in single-channel conductance and the time constant of current activation.
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