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The influence of gustatory and olfactory experiences on responsiveness to reward in the honeybee.

Ramírez GP, Martínez AS, Fernández VM, Corti Bielsa G, Farina WM - PLoS ONE (2010)

Bottom Line: This adjustment is generally associated with the fact that individuals of different ages display different response thresholds to given stimuli, which determine specific behaviors.In contrast no differences in worker responses were observed when presented with odor only in the rearing environment.This work demonstrates the accessibility of chemosensory information in the honeybee colonies with respect to incoming nectar.

View Article: PubMed Central - PubMed

Affiliation: Grupo de Estudio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, IFIBYNE-CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina.

ABSTRACT

Background: Honeybees (Apis mellifera) exhibit an extraordinarily tuned division of labor that depends on age polyethism. This adjustment is generally associated with the fact that individuals of different ages display different response thresholds to given stimuli, which determine specific behaviors. For instance, the sucrose-response threshold (SRT) which largely depends on genetic factors may also be affected by the nectar sugar content. However, it remains unknown whether SRTs in workers of different ages and tasks can differ depending on gustatory and olfactory experiences.

Methodology: Groups of worker bees reared either in an artificial environment or else in a queen-right colony, were exposed to different reward conditions at different adult ages. Gustatory response scores (GRSs) and odor-memory retrieval were measured in bees that were previously exposed to changes in food characteristics.

Principal findings: Results show that the gustatory responses of pre-foraging-aged bees are affected by changes in sucrose solution concentration and also to the presence of an odor provided it is presented as scented sucrose solution. In contrast no differences in worker responses were observed when presented with odor only in the rearing environment. Fast modulation of GRSs was observed in older bees (12-16 days of age) which are commonly involved in food processing tasks within the hive, while slower modulation times were observed in younger bees (commonly nurse bees, 6-9 days of age). This suggests that older food-processing bees have a higher plasticity when responding to fluctuations in resource information than younger hive bees. Adjustments in the number of trophallaxis events were also found when scented food circulated inside the nest, and this was positively correlated with the differences in timing observed in gustatory responsiveness and memory retention for hive bees of different age classes.

Conclusions: This work demonstrates the accessibility of chemosensory information in the honeybee colonies with respect to incoming nectar. The modulation of the sensory-response systems within the hive can have important effects on the dynamics of food transfer and information propagation.

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Related in: MedlinePlus

Memory retention after exposure to scented food.Prior to tests, caged adult bees were fed a constant reward program of unscented 15% w/w sucrose solution. Either at 7 days old (A) or 14 days old (B), percentage of bees that extended their proboscis upon the first presentation of an odor (% PER) was calculated for: the solution odor (linalool, LIO, gray bars), a novel test odor (phenylacetaldehyde, PHE, dark gray bars), or both (white bars) in bees that were fed for 24 hours with a scented 15% w/w sucrose solution. Asterisks indicate statistical differences (G-test for, ** p<0.01; for details see the text). The number of observations is shown in parentheses.
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pone-0013498-g003: Memory retention after exposure to scented food.Prior to tests, caged adult bees were fed a constant reward program of unscented 15% w/w sucrose solution. Either at 7 days old (A) or 14 days old (B), percentage of bees that extended their proboscis upon the first presentation of an odor (% PER) was calculated for: the solution odor (linalool, LIO, gray bars), a novel test odor (phenylacetaldehyde, PHE, dark gray bars), or both (white bars) in bees that were fed for 24 hours with a scented 15% w/w sucrose solution. Asterisks indicate statistical differences (G-test for, ** p<0.01; for details see the text). The number of observations is shown in parentheses.

Mentions: We also evaluated the PER after different durations of exposure to the odor (a measurement of the CR). Results showed that 7-day-old bees increased their PER frequencies to the solution odor (LIO) throughout the stimulation period (G test: G = 17.39, p = 0.0002, N = 242, Fig. 3A). Multiple comparisons allowed us to detect statistically significant differences between 0 h and 6 h after scenting the solution with LIO (p<0.0001; Fig. 3A) and between 0 h and 24 h (p<0.0001; Fig. 3A), but not between 6 h and 24 h (p>0.5; Fig. 3A). PER frequencies to LIO (solution odor) increased in 14-day-old bees (G test for: G = 38.49, p<0.0001, N = 433; Fig. 3B), while we observed minimal PER levels in tests with the novel odor (PHE) and a mixture of both odors (LIO and PHE). Multiple comparisons showed statistical differences between 0 h and 6 h after scenting the solution with LIO (p<0.0001; Fig. 3B) and between 0 h and 24 h (p<0.0001, Fig. 3B), but not between 6 h and 24 h (p>0.05, Fig. 3B).


The influence of gustatory and olfactory experiences on responsiveness to reward in the honeybee.

Ramírez GP, Martínez AS, Fernández VM, Corti Bielsa G, Farina WM - PLoS ONE (2010)

Memory retention after exposure to scented food.Prior to tests, caged adult bees were fed a constant reward program of unscented 15% w/w sucrose solution. Either at 7 days old (A) or 14 days old (B), percentage of bees that extended their proboscis upon the first presentation of an odor (% PER) was calculated for: the solution odor (linalool, LIO, gray bars), a novel test odor (phenylacetaldehyde, PHE, dark gray bars), or both (white bars) in bees that were fed for 24 hours with a scented 15% w/w sucrose solution. Asterisks indicate statistical differences (G-test for, ** p<0.01; for details see the text). The number of observations is shown in parentheses.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2958144&req=5

pone-0013498-g003: Memory retention after exposure to scented food.Prior to tests, caged adult bees were fed a constant reward program of unscented 15% w/w sucrose solution. Either at 7 days old (A) or 14 days old (B), percentage of bees that extended their proboscis upon the first presentation of an odor (% PER) was calculated for: the solution odor (linalool, LIO, gray bars), a novel test odor (phenylacetaldehyde, PHE, dark gray bars), or both (white bars) in bees that were fed for 24 hours with a scented 15% w/w sucrose solution. Asterisks indicate statistical differences (G-test for, ** p<0.01; for details see the text). The number of observations is shown in parentheses.
Mentions: We also evaluated the PER after different durations of exposure to the odor (a measurement of the CR). Results showed that 7-day-old bees increased their PER frequencies to the solution odor (LIO) throughout the stimulation period (G test: G = 17.39, p = 0.0002, N = 242, Fig. 3A). Multiple comparisons allowed us to detect statistically significant differences between 0 h and 6 h after scenting the solution with LIO (p<0.0001; Fig. 3A) and between 0 h and 24 h (p<0.0001; Fig. 3A), but not between 6 h and 24 h (p>0.5; Fig. 3A). PER frequencies to LIO (solution odor) increased in 14-day-old bees (G test for: G = 38.49, p<0.0001, N = 433; Fig. 3B), while we observed minimal PER levels in tests with the novel odor (PHE) and a mixture of both odors (LIO and PHE). Multiple comparisons showed statistical differences between 0 h and 6 h after scenting the solution with LIO (p<0.0001; Fig. 3B) and between 0 h and 24 h (p<0.0001, Fig. 3B), but not between 6 h and 24 h (p>0.05, Fig. 3B).

Bottom Line: This adjustment is generally associated with the fact that individuals of different ages display different response thresholds to given stimuli, which determine specific behaviors.In contrast no differences in worker responses were observed when presented with odor only in the rearing environment.This work demonstrates the accessibility of chemosensory information in the honeybee colonies with respect to incoming nectar.

View Article: PubMed Central - PubMed

Affiliation: Grupo de Estudio de Insectos Sociales, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, IFIBYNE-CONICET, Universidad de Buenos Aires, Buenos Aires, Argentina.

ABSTRACT

Background: Honeybees (Apis mellifera) exhibit an extraordinarily tuned division of labor that depends on age polyethism. This adjustment is generally associated with the fact that individuals of different ages display different response thresholds to given stimuli, which determine specific behaviors. For instance, the sucrose-response threshold (SRT) which largely depends on genetic factors may also be affected by the nectar sugar content. However, it remains unknown whether SRTs in workers of different ages and tasks can differ depending on gustatory and olfactory experiences.

Methodology: Groups of worker bees reared either in an artificial environment or else in a queen-right colony, were exposed to different reward conditions at different adult ages. Gustatory response scores (GRSs) and odor-memory retrieval were measured in bees that were previously exposed to changes in food characteristics.

Principal findings: Results show that the gustatory responses of pre-foraging-aged bees are affected by changes in sucrose solution concentration and also to the presence of an odor provided it is presented as scented sucrose solution. In contrast no differences in worker responses were observed when presented with odor only in the rearing environment. Fast modulation of GRSs was observed in older bees (12-16 days of age) which are commonly involved in food processing tasks within the hive, while slower modulation times were observed in younger bees (commonly nurse bees, 6-9 days of age). This suggests that older food-processing bees have a higher plasticity when responding to fluctuations in resource information than younger hive bees. Adjustments in the number of trophallaxis events were also found when scented food circulated inside the nest, and this was positively correlated with the differences in timing observed in gustatory responsiveness and memory retention for hive bees of different age classes.

Conclusions: This work demonstrates the accessibility of chemosensory information in the honeybee colonies with respect to incoming nectar. The modulation of the sensory-response systems within the hive can have important effects on the dynamics of food transfer and information propagation.

Show MeSH
Related in: MedlinePlus