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Published on: May 29, 2013
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Nociception in Chicken Embryos, Part II: Embryonal Development of Electroencephalic Neuronal Activity In Ovo as a
Sandra Kollmansperger1, Malte Anders1,2, Julia Werner3
1Department of Anaesthesiology and Intensive Care, School of Medicine, Technical University Munich, 81675 Munich, Germany.
Animals : an Open Access Journal From MDPI
|September 28, 2023
Summary
German regulations prohibit chicken culling, requiring embryonic sex selection before pain perception. This study identified day 13 as the earliest embryonic stage capable of processing noxious stimuli, though direct nociceptive responses were not observed.
Area of Science:
- Animal Welfare Science
- Developmental Neuroscience
- Avian Embryology
Background:
- German legislation effective 2022 mandates embryonic sex determination to prevent chick culling.
- Understanding the earliest onset of nociception (pain perception) in avian embryos is crucial for ethical practices.
Purpose of the Study:
- To determine the earliest developmental stage in chicken embryos capable of perceiving and processing noxious stimuli *in ovo*.
- To investigate the potential for nociceptive responses in the embryonic avian brain.
Main Methods:
- Electroencephalogram (EEG) recordings were taken from hyperpallial brain sites of chicken embryos *in ovo*.
- Noxious stimuli were applied, and temporal and spectral EEG analyses were performed.
- Event-related potential (ERP), event-related spectral perturbation (ERSP), and inter-trial coherence (ITC) analyses were conducted.
Main Results:
- Physiological neuronal signals were detectable from developmental day 13 onwards.
- No phase-locked nociceptive responses were identified through ERP/ERSP/ITC analysis.
- While central nociceptive responses were not documented, responses from other brain areas and the impact of experimental stress cannot be ruled out.
Conclusions:
- Developmental day 13 represents the earliest identified stage where chicken embryos may possess the capacity to receive and process nociceptive stimuli.
- Further research is needed to fully elucidate nociceptive pathways and the influence of experimental conditions on embryonic perception.
