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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

Foraging behaviour in honey bees following cocaine administration.(A) Scatter plot showing the effect of topical cocaine treatment on preference for the green arm. Each point represents one bee. Dotted lines mark median values for each treatment group. The preference for the green arm was significantly higher for cocaine-treated than control-treated bees (Mann–Witney U = 2, 185, p = 0.0038). (B) Effect of volatilised cocaine treatment on visitation rate at a sucrose feeder (error bars represent standard error). Bees treated with volatilised cocaine (grey bars) increased their rate of foraging relative to controls (white bars) when foraging at a 0.5 M sucrose feeder (t70 = 5.0710, p = 0.00003), but not at a 2 M sucrose feeder (t70 = −0.2087, p = 0.8353).
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fig-2: Foraging behaviour in honey bees following cocaine administration.(A) Scatter plot showing the effect of topical cocaine treatment on preference for the green arm. Each point represents one bee. Dotted lines mark median values for each treatment group. The preference for the green arm was significantly higher for cocaine-treated than control-treated bees (Mann–Witney U = 2, 185, p = 0.0038). (B) Effect of volatilised cocaine treatment on visitation rate at a sucrose feeder (error bars represent standard error). Bees treated with volatilised cocaine (grey bars) increased their rate of foraging relative to controls (white bars) when foraging at a 0.5 M sucrose feeder (t70 = 5.0710, p = 0.00003), but not at a 2 M sucrose feeder (t70 = −0.2087, p = 0.8353).

Mentions: Repeatedly treating bees with 3 µg cocaine in DMF at a sucrose feeder enhanced bees’ preference for that feeder in a choice assay when compared to bees treated with DMF as a control (Mann–Witney test: U = 2, 185, p = 0.0038; Effect size: r = −0.25). Treating bees with cocaine at a feeder while they were foraging resulted in a greater preference for that feeder in a free-choice test when compared to bees treated with DMF (vehicle control) while foraging at the feeder (Fig. 2A).


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

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

Foraging behaviour in honey bees following cocaine administration.(A) Scatter plot showing the effect of topical cocaine treatment on preference for the green arm. Each point represents one bee. Dotted lines mark median values for each treatment group. The preference for the green arm was significantly higher for cocaine-treated than control-treated bees (Mann–Witney U = 2, 185, p = 0.0038). (B) Effect of volatilised cocaine treatment on visitation rate at a sucrose feeder (error bars represent standard error). Bees treated with volatilised cocaine (grey bars) increased their rate of foraging relative to controls (white bars) when foraging at a 0.5 M sucrose feeder (t70 = 5.0710, p = 0.00003), but not at a 2 M sucrose feeder (t70 = −0.2087, p = 0.8353).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig-2: Foraging behaviour in honey bees following cocaine administration.(A) Scatter plot showing the effect of topical cocaine treatment on preference for the green arm. Each point represents one bee. Dotted lines mark median values for each treatment group. The preference for the green arm was significantly higher for cocaine-treated than control-treated bees (Mann–Witney U = 2, 185, p = 0.0038). (B) Effect of volatilised cocaine treatment on visitation rate at a sucrose feeder (error bars represent standard error). Bees treated with volatilised cocaine (grey bars) increased their rate of foraging relative to controls (white bars) when foraging at a 0.5 M sucrose feeder (t70 = 5.0710, p = 0.00003), but not at a 2 M sucrose feeder (t70 = −0.2087, p = 0.8353).
Mentions: Repeatedly treating bees with 3 µg cocaine in DMF at a sucrose feeder enhanced bees’ preference for that feeder in a choice assay when compared to bees treated with DMF as a control (Mann–Witney test: U = 2, 185, p = 0.0038; Effect size: r = −0.25). Treating bees with cocaine at a feeder while they were foraging resulted in a greater preference for that feeder in a free-choice test when compared to bees treated with DMF (vehicle control) while foraging at the feeder (Fig. 2A).

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