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Cocaine affects foraging behaviour and biogenic amine modulated behavioural reflexes in honey bees.

Søvik E, Even N, Radford CW, Barron AB - PeerJ (2014)

Bottom Line: Biogenic amine pathways are involved in reward processing across diverse animal phyla, however whether cocaine acts on these neurochemical pathways to cause similar rewarding behavioural effects in animal phyla other than mammals is unclear.Both of these simple reflexes are modulated by biogenic amines.Since insect reward responses involve both octopamine and dopamine signalling, we conclude that cocaine treatment altered diverse reward-related aspects of behaviour in bees.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biological Sciences, Macquarie University , Sydney , Australia ; Department of Biology, Washington University in St. Louis , St. Louis , USA.

ABSTRACT
In humans and other mammals, drugs of abuse alter the function of biogenic amine pathways in the brain leading to the subjective experience of reward and euphoria. Biogenic amine pathways are involved in reward processing across diverse animal phyla, however whether cocaine acts on these neurochemical pathways to cause similar rewarding behavioural effects in animal phyla other than mammals is unclear. Previously, it has been shown that bees are more likely to dance (a signal of perceived reward) when returning from a sucrose feeder after cocaine treatment. Here we examined more broadly whether cocaine altered reward-related behaviour, and biogenic amine modulated behavioural responses in bees. Bees developed a preference for locations at which they received cocaine, and when foraging at low quality sucrose feeders increase their foraging rate in response to cocaine treatment. Cocaine also increased reflexive proboscis extension to sucrose, and sting extension to electric shock. Both of these simple reflexes are modulated by biogenic amines. This shows that systemic cocaine treatment alters behavioural responses that are modulated by biogenic amines in insects. Since insect reward responses involve both octopamine and dopamine signalling, we conclude that cocaine treatment altered diverse reward-related aspects of behaviour in bees. We discuss the implications of these results for understanding the ecology of cocaine as a plant defence compound. Our findings further validate the honey bee as a model system for understanding the behavioural impacts of cocaine, and potentially other drugs of abuse.

No MeSH data available.


Related in: MedlinePlus

Behavioural responsiveness following cocaine administration in honey bees.(A) Proportion of bees responding to 10% sucrose following treatment with 0 or 10 µg of volatilised cocaine (error bars represents standard error and letters denote statistically different groups). There was a significant increase in sucrose responsiveness in bees treated with 10 µg cocaine relative to control (χ2 = 6.1013, df = 1, p = 0.0135). (B) Proportion of bees responding to 10% sucrose following treatment with 0, 5, 10, 20, or 50 µg of volatilised cocaine. There was a dose-dependent relationship between cocaine dose and sucrose responsiveness (χ2 = 14.089, df = 4, p = 0.0070). (C) Shock responsiveness of bees following cocaine administration. Curves are based on weibull distributions of shock responsiveness for each group. Comparisons are based on estimates of EV50 for 40 bees per group (F4,40 = 5.4, p = 0.0015). Pairwise comparisons found that the 50 µg group was different from all other groups, while the remaining cocaine treated groups were different from controls.
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fig-3: Behavioural responsiveness following cocaine administration in honey bees.(A) Proportion of bees responding to 10% sucrose following treatment with 0 or 10 µg of volatilised cocaine (error bars represents standard error and letters denote statistically different groups). There was a significant increase in sucrose responsiveness in bees treated with 10 µg cocaine relative to control (χ2 = 6.1013, df = 1, p = 0.0135). (B) Proportion of bees responding to 10% sucrose following treatment with 0, 5, 10, 20, or 50 µg of volatilised cocaine. There was a dose-dependent relationship between cocaine dose and sucrose responsiveness (χ2 = 14.089, df = 4, p = 0.0070). (C) Shock responsiveness of bees following cocaine administration. Curves are based on weibull distributions of shock responsiveness for each group. Comparisons are based on estimates of EV50 for 40 bees per group (F4,40 = 5.4, p = 0.0015). Pairwise comparisons found that the 50 µg group was different from all other groups, while the remaining cocaine treated groups were different from controls.

Mentions: Treatment with 10 µg of volatilised cocaine increased bees responsiveness to sucrose (χ2 = 6.0268, df = 1, p = 0.0141; Effect size: d = 0.6331; Fig. 3A). The effect was dependent on the cocaine dose. Bees treated with 5 and 10 µg of cocaine were significantly more responsive to sucrose than controls (χ2 = 14.089, df = 4, p = 0.0070; Fig. 3B), while bees treated with 20 or 50 µg of cocaine did not differ from controls. The control treatment differed quite markedly between two experiments; however, this is likely because the two experiments were performed at different times of the year. Sucrose responsiveness varies with season and environmental conditions. The important aspect is the difference between the cocaine treated bees and the control treated bees in a given experiment.


Cocaine affects foraging behaviour and biogenic amine modulated behavioural reflexes in honey bees.

Søvik E, Even N, Radford CW, Barron AB - PeerJ (2014)

Behavioural responsiveness following cocaine administration in honey bees.(A) Proportion of bees responding to 10% sucrose following treatment with 0 or 10 µg of volatilised cocaine (error bars represents standard error and letters denote statistically different groups). There was a significant increase in sucrose responsiveness in bees treated with 10 µg cocaine relative to control (χ2 = 6.1013, df = 1, p = 0.0135). (B) Proportion of bees responding to 10% sucrose following treatment with 0, 5, 10, 20, or 50 µg of volatilised cocaine. There was a dose-dependent relationship between cocaine dose and sucrose responsiveness (χ2 = 14.089, df = 4, p = 0.0070). (C) Shock responsiveness of bees following cocaine administration. Curves are based on weibull distributions of shock responsiveness for each group. Comparisons are based on estimates of EV50 for 40 bees per group (F4,40 = 5.4, p = 0.0015). Pairwise comparisons found that the 50 µg group was different from all other groups, while the remaining cocaine treated groups were different from controls.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232840&req=5

fig-3: Behavioural responsiveness following cocaine administration in honey bees.(A) Proportion of bees responding to 10% sucrose following treatment with 0 or 10 µg of volatilised cocaine (error bars represents standard error and letters denote statistically different groups). There was a significant increase in sucrose responsiveness in bees treated with 10 µg cocaine relative to control (χ2 = 6.1013, df = 1, p = 0.0135). (B) Proportion of bees responding to 10% sucrose following treatment with 0, 5, 10, 20, or 50 µg of volatilised cocaine. There was a dose-dependent relationship between cocaine dose and sucrose responsiveness (χ2 = 14.089, df = 4, p = 0.0070). (C) Shock responsiveness of bees following cocaine administration. Curves are based on weibull distributions of shock responsiveness for each group. Comparisons are based on estimates of EV50 for 40 bees per group (F4,40 = 5.4, p = 0.0015). Pairwise comparisons found that the 50 µg group was different from all other groups, while the remaining cocaine treated groups were different from controls.
Mentions: Treatment with 10 µg of volatilised cocaine increased bees responsiveness to sucrose (χ2 = 6.0268, df = 1, p = 0.0141; Effect size: d = 0.6331; Fig. 3A). The effect was dependent on the cocaine dose. Bees treated with 5 and 10 µg of cocaine were significantly more responsive to sucrose than controls (χ2 = 14.089, df = 4, p = 0.0070; Fig. 3B), while bees treated with 20 or 50 µg of cocaine did not differ from controls. The control treatment differed quite markedly between two experiments; however, this is likely because the two experiments were performed at different times of the year. Sucrose responsiveness varies with season and environmental conditions. The important aspect is the difference between the cocaine treated bees and the control treated bees in a given experiment.

Bottom Line: Biogenic amine pathways are involved in reward processing across diverse animal phyla, however whether cocaine acts on these neurochemical pathways to cause similar rewarding behavioural effects in animal phyla other than mammals is unclear.Both of these simple reflexes are modulated by biogenic amines.Since insect reward responses involve both octopamine and dopamine signalling, we conclude that cocaine treatment altered diverse reward-related aspects of behaviour in bees.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Biological Sciences, Macquarie University , Sydney , Australia ; Department of Biology, Washington University in St. Louis , St. Louis , USA.

ABSTRACT
In humans and other mammals, drugs of abuse alter the function of biogenic amine pathways in the brain leading to the subjective experience of reward and euphoria. Biogenic amine pathways are involved in reward processing across diverse animal phyla, however whether cocaine acts on these neurochemical pathways to cause similar rewarding behavioural effects in animal phyla other than mammals is unclear. Previously, it has been shown that bees are more likely to dance (a signal of perceived reward) when returning from a sucrose feeder after cocaine treatment. Here we examined more broadly whether cocaine altered reward-related behaviour, and biogenic amine modulated behavioural responses in bees. Bees developed a preference for locations at which they received cocaine, and when foraging at low quality sucrose feeders increase their foraging rate in response to cocaine treatment. Cocaine also increased reflexive proboscis extension to sucrose, and sting extension to electric shock. Both of these simple reflexes are modulated by biogenic amines. This shows that systemic cocaine treatment alters behavioural responses that are modulated by biogenic amines in insects. Since insect reward responses involve both octopamine and dopamine signalling, we conclude that cocaine treatment altered diverse reward-related aspects of behaviour in bees. We discuss the implications of these results for understanding the ecology of cocaine as a plant defence compound. Our findings further validate the honey bee as a model system for understanding the behavioural impacts of cocaine, and potentially other drugs of abuse.

No MeSH data available.


Related in: MedlinePlus