scholarly journals Evidence for instantaneous e-vector detection in the honeybee using an associative learning paradigm

2011 ◽  
Vol 279 (1728) ◽  
pp. 535-542 ◽  
Author(s):  
Midori Sakura ◽  
Ryuichi Okada ◽  
Hitoshi Aonuma
Keyword(s):  
Compound Eye ◽  
Polarized Light ◽  
Green Light ◽  
Sequential Method ◽  
Sugar Water ◽  
Conditioning Paradigm ◽  
Flight Direction ◽  
Vector Information ◽  
Proboscis Extension ◽  
Vector Orientation

Many insects use the polarization pattern of the sky for obtaining compass information during orientation or navigation. E-vector information is collected by a specialized area in the dorsal-most part of the compound eye, the dorsal rim area (DRA). We tested honeybees' capability of learning certain e-vector orientations by using a classical conditioning paradigm with the proboscis extension reflex. When one e-vector orientation (CS+) was associated with sugar water, while another orientation (CS−) was not rewarded, the honeybees could discriminate CS+ from CS−. Bees whose DRA was inactivated by painting did not learn CS+. When ultraviolet (UV) polarized light (350 nm) was used for CS, the bees discriminated CS+ from CS−, but no discrimination was observed in blue (442 nm) or green light (546 nm). Our data indicate that honeybees can learn and discriminate between different e-vector orientations, sensed by the UV receptors of the DRA, suggesting that bees can determine their flight direction from polarized UV skylight during foraging. Fixing the bees' heads during the experiments did not prevent learning, indicating that they use an ‘instantaneous’ algorithm of e-vector detection; that is, the bees do not need to actively scan the sky with their DRAs (‘sequential’ method) to determine e-vector orientation.

scholarly journals Orientation to polarized light in tethered flying honeybees

2019 ◽  
Author(s):  
Norihiro Kobayashi ◽  
Ryuichi Okada ◽  
Midori Sakura
Keyword(s):  
Light Stimulus ◽  
Polarized Light ◽  
Rotation Frequency ◽  
Black Paint ◽  
Flight Direction ◽  
Periodic Movement ◽  
High Preference ◽  
Foraging Experience ◽  
Vector Information ◽  
Vector Orientation

ABSTRACTBehavioral responses of honeybees to a zenithal polarized light stimulus were observed using a tethered animal in a flight simulator. Flight direction of the bee was recorded by monitoring the horizontal movement of its abdomen, which was strongly anti-correlated with its torque. When the e-vector orientation of the polarized light was rotated clockwise or counterclockwise, the bee responded with periodic right-and-left abdominal movements; however, the bee did not show any clear periodic movement under the static e-vector or depolarized stimulus. The steering frequency of the bee was well coordinated with the e-vector rotation frequency of the stimulus, indicating that the flying bee oriented itself to a certain e-vector orientation, i.e., exhibited polarotaxis. The percentage of bees exhibiting clear polarotaxis was much smaller under the fast stimulus (3.6 ° s-1) compared with that of the slow stimulus (0.9 or 1.8 ° s-1). The bee did not demonstrate any polarotactic behavior after the dorsal rim region of its eyes, which mediates insect polarization vision in general, was bilaterally covered with black paint. The bees demonstrated a high preference for e-vector orientations between 120 to 180°. Each bee exhibited similar e-vector preferences under clockwise and counterclockwise stimuli, indicating that each bee has its own e-vector preference, which probably depends on the bee’s previous foraging experience. Our results strongly suggest that the flying honeybees utilize the e-vector information from the skylight to deduce their heading orientation for navigation.Summary statementTethered flying bees exhibited polarotaxis under a zenithal rotating e-vector stimulus, in which their right-and-left abdominal movements were coincident with the rotation of the stimulus.

scholarly journals How polarization-sensitive interneurones of crickets perform at low degrees of polarization

1996 ◽  
Vol 199 (7) ◽  
pp. 1467-1475 ◽  
Author(s):  
T Labhart
Keyword(s):  
Compound Eye ◽  
Polarized Light ◽  
Degree Of Polarization ◽  
Modulation Amplitude ◽  
Optimal Conditions ◽  
Vector Information ◽  
Vector Orientation ◽  
D Values ◽  
Low Degrees ◽  
Sinusoidal Function

In crickets, polarized-light information from the blue sky is processed by polarization-opponent interneurones (POL-neurones). These neurones receive input from the polarization-sensitive blue receptors found in the specialized dorsal rim area of the compound eye. Even under optimal conditions, the degree of polarization d does not exceed 0.75 in the blue region of the spectrum and it is normally much lower. The aim of this study is to assess how POL-neurones perform at low, physiologically relevant degrees of polarization. The spiking activity of POL-neurones is a sinusoidal function of e-vector orientation with a 180 ° period. The modulation amplitude of this function decreases strongly as the degree of polarization decreases. However, our data indicate that POL-neurones can signal e-vector information at d-values as low as 0.05, which would allow the polarization-sensitive system of crickets to exploit polarized light from the sky for orientation even under unfavourable meteorological conditions.

scholarly journals Orientation to polarized light in tethered flying honeybees

2020 ◽  
Vol 223 (23) ◽  
pp. jeb228254
Author(s):  
Norihiro Kobayashi ◽  
Ryuichi Okada ◽  
Midori Sakura
Keyword(s):  
Light Stimulus ◽  
Polarized Light ◽  
Rotation Frequency ◽  
Compass Orientation ◽  
Black Paint ◽  
Flight Direction ◽  
Periodic Movement ◽  
Vector Information ◽  
Vector Orientation ◽  
Partial Plane

ABSTRACTMany insects exploit the partial plane polarization of skylight for visual compass orientation and/or navigation. In the present study, using a tethering system, we investigated how flying bees respond to polarized light stimuli. The behavioral responses of honeybees (Apis mellifera) to a zenithal polarized light stimulus were observed using a tethered animal in a flight simulator. Flight direction of the bee was recorded by monitoring the horizontal movement of its abdomen, which was strongly anti-correlated with its torque. When the e-vector orientation of the polarized light was rotated clockwise or counterclockwise, the bee responded with periodic right-and-left abdominal movements; however, the bee did not show any clear periodic movement under the static e-vector or depolarized stimulus. The steering frequency of the bee was well coordinated with the e-vector rotation frequency of the stimulus, indicating that the flying bee oriented itself to a certain e-vector orientation, i.e. exhibited polarotaxis. The percentage of bees exhibiting clear polarotaxis was much smaller under the fast stimulus (3.6 deg s−1) compared with that under a slow stimulus (0.9 or 1.8 deg s−1). Bees did not demonstrate any polarotactic behavior after the dorsal rim area of the eyes, which mediates insect polarization vision in general, was bilaterally covered with black paint. Preferred e-vector orientations under the clockwise stimulus varied among individuals and distributed throughout −90 to 90 deg. Some bees showed similar preferred e-vector orientations for clockwise and counterclockwise stimuli whereas others did not. Our results strongly suggest that flying honeybees utilize the e-vector information from the skylight to deduce their heading orientation for navigation.

scholarly journals Heading choices of flying Drosophila under changing angles of polarized light

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Thomas F. Mathejczyk ◽  
Mathias F. Wernet
Keyword(s):  
Incident Angle ◽  
Polarized Light ◽  
Green Light ◽  
Behavioral Responses ◽  
Open Loop ◽  
Slow Rotation ◽  
Visually Guided ◽  
Polarization Pattern ◽  
Linearly Polarized ◽  
3D Printed

AbstractMany navigating insects include the celestial polarization pattern as an additional visual cue to orient their travels. Spontaneous orientation responses of both walking and flying fruit flies (Drosophila melanogaster) to linearly polarized light have previously been demonstrated. Using newly designed modular flight arenas consisting entirely of off-the-shelf parts and 3D-printed components we present individual flying flies with a slow and continuous rotational change in the incident angle of linear polarization. Under such open-loop conditions, single flies choose arbitrary headings with respect to the angle of polarized light and show a clear tendency to maintain those chosen headings for several minutes, thereby adjusting their course to the slow rotation of the incident stimulus. Importantly, flies show the tendency to maintain a chosen heading even when two individual test periods under a linearly polarized stimulus are interrupted by an epoch of unpolarized light lasting several minutes. Finally, we show that these behavioral responses are wavelength-specific, existing under polarized UV stimulus while being absent under polarized green light. Taken together, these findings provide further evidence supporting Drosophila’s abilities to use celestial cues for visually guided navigation and course correction.

The tiered retina of Dytiscus : a new type of compound eye

1970 ◽  
Vol 175 (1038) ◽  
pp. 83-94 ◽  
Keyword(s):  
Compound Eye ◽  
Electrical Coupling ◽  
Polarized Light ◽  
Light Sensitivity ◽  
Sectional Area ◽  
Cross Sectional ◽  
Light Passing ◽  
Small Fields ◽  
New Type ◽  
Different Levels

The retina of Dytiscus is tiered, with proximal and distal layers of receptors at different levels. Photoreceptor units of the proximal retina of the eye of Dytiscus have fields of view so wide that light entering by any facet is able to excite a receptor belonging virtually to any ommatidium in the light- or dark-adapted eye. Although the distal rhabdomeres may have small fields of view, the proximal retina is clearly not adapted for perception of form or movement. The sensitivity of proximal retinula units is compatible with the observations that light passing through many facets sums upon them and that their rhabdomeres are relatively large and jointly occupy the whole cross-sectional area of the eye. The lack of polarized light sensitivity of the proximal retinula units can be attributed to electrical coupling between cells with tubules oriented in different directions within each ommatidium.

scholarly journals Homothorax controls a binary Rhodopsin switch in Drosophila ocelli

PLoS Genetics ◽  
2021 ◽  
Vol 17 (7) ◽  
pp. e1009460
Author(s):  
Abhishek Kumar Mishra ◽  
Cornelia Fritsch ◽  
Roumen Voutev ◽  
Richard S. Mann ◽  
Simon G. Sprecher
Keyword(s):  
Drosophila Melanogaster ◽  
Visual Perception ◽  
Compound Eye ◽  
Polarized Light ◽  
Fruit Fly ◽  
Compound Eyes ◽  
Ancestral Gene ◽  
Evolutionary Diversification ◽  
Opsin Genes ◽  
A Cell

Visual perception of the environment is mediated by specialized photoreceptor (PR) neurons of the eye. Each PR expresses photosensitive opsins, which are activated by a particular wavelength of light. In most insects, the visual system comprises a pair of compound eyes that are mainly associated with motion, color or polarized light detection, and a triplet of ocelli that are thought to be critical during flight to detect horizon and movements. It is widely believed that the evolutionary diversification of compound eye and ocelli in insects occurred from an ancestral visual organ around 500 million years ago. Concurrently, opsin genes were also duplicated to provide distinct spectral sensitivities to different PRs of compound eye and ocelli. In the fruit fly Drosophila melanogaster, Rhodopsin1 (Rh1) and Rh2 are closely related opsins that originated from the duplication of a single ancestral gene. However, in the visual organs, Rh2 is uniquely expressed in ocelli whereas Rh1 is uniquely expressed in outer PRs of the compound eye. It is currently unknown how this differential expression of Rh1 and Rh2 in the two visual organs is controlled to provide unique spectral sensitivities to ocelli and compound eyes. Here, we show that Homothorax (Hth) is expressed in ocelli and confers proper rhodopsin expression. We find that Hth controls a binary Rhodopsin switch in ocelli to promote Rh2 expression and repress Rh1 expression. Genetic and molecular analysis of rh1 and rh2 supports that Hth acts through their promoters to regulate Rhodopsin expression in the ocelli. Finally, we also show that when ectopically expressed in the retina, hth is sufficient to induce Rh2 expression only at the outer PRs in a cell autonomous manner. We therefore propose that the diversification of rhodpsins in the ocelli and retinal outer PRs occurred by duplication of an ancestral gene, which is under the control of Homothorax.

scholarly journals Honey bees can store and retrieve independent memory traces after complex experiences that combine appetitive and aversive associations

2021 ◽  
Author(s):  
Martin Klappenbach ◽  
Agustin E Lara ◽  
Fernando F Locatelli
Keyword(s):  
Honey Bees ◽  
Differential Conditioning ◽  
Training Session ◽  
Aversive Conditioning ◽  
Appetitive Conditioning ◽  
Olfactory Conditioning ◽  
Proboscis Extension Response ◽  
Conditioning Paradigm ◽  
Aversive Events ◽  
Proboscis Extension

Real-world experiences do often mix appetitive and aversive events. Understanding the ability of animals to extract, store and use this information is an important issue in neurobiology. We used honey bees as model to study learning and memory after a differential conditioning that combines appetitive and aversive training trials. First of all, we describe an aversive conditioning paradigm that constitutes a clear opposite of the well known appetitive olfactory conditioning of the proboscis extension response. A neutral odour is presented paired with the bitter substance quinine. Aversive memory is evidenced later as an odour-specific impairment in appetitive conditioning. Then we tested the effect of mixing appetitive and aversive conditioning trials distributed along the same training session. Differential conditioning protocols like this were used before to study the ability to discriminate odours, however they were not focused on whether appetitive and aversive memories are formed. We found that after a differential conditioning, honey bees establish independent appetitive and aversive memories that do not interfere with each other during acquisition or storage. Finally, we moved the question forward to retrieval and memory expression to evaluate what happens when appetitive and the aversive learned odours are mixed during test. Interestingly, opposite memories compete in a way that they do not cancel each other out. Honey bees showed the ability to switch from expressing appetitive to aversive memory depending on their satiation level.

scholarly journals Comparing the appetitive learning performance of six European honeybee subspecies in a common apiary

2021 ◽  
Author(s):  
Ricarda Scheiner ◽  
Kayun Lim ◽  
Marina D Meixner ◽  
Martin S Gabel
Keyword(s):  
Cognitive Skills ◽  
Learning Performance ◽  
Proboscis Extension Response ◽  
Sugar Water ◽  
Appetitive Learning ◽  
Proboscis Extension ◽  
Differential Responsiveness ◽  
Honeybee Subspecies ◽  
European Honeybee ◽  
Sucrose Responsiveness

The Western honeybee (Apis mellifera L.) is one of the most widespread insects with numerous subspecies in its native range. In how far adaptation to local habitats has affected the cognitive skills of the different subspecies is an intriguing question which we investigate in this study. Naturally mated queens of the following five subspecies from different parts of Europe were transferred to Southern Germany: A. m. iberiensis from Portugal, A. m. mellifera from Belgium, A. m. macedonica from Greece, A.m. ligustica from Italy and A. m. ruttneri from Malta. We also included the local subspecies A.m. carnica in our study. New colonies were built up in a common apiary where the respective queens were introduced. Worker offspring from the different subspecies was compared in classical olfactory learning performance using the proboscis extension response. Prior to conditioning we measured individual sucrose responsiveness to investigate whether possible differences in learning performances were due to a differential responsiveness to the sugar water reward. Most subspecies did not differ in their appetitive learning performance. However, foragers of the Iberian honeybee, A. m. iberiensis, performed significantly more poorly, despite having a similar sucrose responsiveness. We discuss possible causes for the low cognitive performance of the Iberian honeybees, which may have been shaped by adaptation to local habitat.

An assessment method for dermal structures using cross‐polarized light imaging with a green light‐emitting diode

2020 ◽  
Vol 26 (6) ◽  
pp. 932-936
Author(s):  
Ji Hyuck Hong ◽  
Sung Jin Park ◽  
Min Seok Ham ◽  
Dai Hyun Kim ◽  
Im Joo Rhyu ◽  
...  
Keyword(s):  
Light Emitting Diode ◽  
Polarized Light ◽  
Green Light ◽  
Assessment Method ◽  
Light Emitting ◽  
Polarized Light Imaging
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