Abstract
Immune activation has been suggested as a major factor influencing social interactions in pigs, with outbreaks of damaging behaviours such as tail biting as a possible result. To address this, cytokine activated signalling pathways that may be involved in inducing behavioural alterations were examined by using an LPS-model. Fifty-two female pigs were allocated to four treatments comprising two injections: saline–saline, saline–LPS (1.2 μg kg-1), ketoprofen (6 mg kg-1)–saline, and ketoprofen–LPS. General activity and social behaviour were observed at specific time intervals. Saliva was analysed for cortisol, adenosine deaminase and haptoglobin. Plasma was analysed for tryptophan and kynurenine. At 72 hours after the injection, the pigs were humanely killed, and the frontal cortex, hippocampus, hypothalamus, and brain stem were sampled and analysed for cytokines, tryptophan, kynurenine and monoamines.
LPS activated the HPA-axis, triggered the acute phase response and elicited behavioural signs of sickness within six hours after the challenge. Ketoprofen attenuated these effects. LPS did not affect central pro-inflammatory cytokines (TNF-α, IFN-γ, IL-18), but depleted peripheral and central tryptophan. Dopamine concentrations in the hypothalamus of LPS-injected pigs were significantly lower compared to saline-injected pigs. LPS-injected pigs had significantly lower concentrations of serotonin in their hypothalamus and noradrenaline in their hippocampus than pigs that were pre-treated with ketoprofen. Changes in social interactions were detected at both individual and group level. Thus, a controlled immune activation altered neurotransmitters and neuromodulators in the brain that are hypothesized to play an important role in the regulation of mood and behaviour.
LPS activated the HPA-axis, triggered the acute phase response and elicited behavioural signs of sickness within six hours after the challenge. Ketoprofen attenuated these effects. LPS did not affect central pro-inflammatory cytokines (TNF-α, IFN-γ, IL-18), but depleted peripheral and central tryptophan. Dopamine concentrations in the hypothalamus of LPS-injected pigs were significantly lower compared to saline-injected pigs. LPS-injected pigs had significantly lower concentrations of serotonin in their hypothalamus and noradrenaline in their hippocampus than pigs that were pre-treated with ketoprofen. Changes in social interactions were detected at both individual and group level. Thus, a controlled immune activation altered neurotransmitters and neuromodulators in the brain that are hypothesized to play an important role in the regulation of mood and behaviour.
Original language | English |
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Number of pages | 1 |
Publication status | Submitted - 12 Feb 2022 |
Event | 14th GEBIN Conference 2022 - Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany Duration: 30 Mar 2022 → 1 Apr 2022 https://www.gebin2022.fau.de/ |
Conference
Conference | 14th GEBIN Conference 2022 |
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Country/Territory | Germany |
City | Erlangen |
Period | 30/03/22 → 1/04/22 |
Internet address |
Keywords
- LPS
- Ketoprofen
- Social behaviour
- Pigs
- Immune response
- Stress response
- Central monoamines
- Neurotransmitters
- Neuromodulators