Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain
The suggestion that decapod crustaceans might experience pain has been dismissed by some authors who claim decapods only respond to noxious stimuli by nociceptive reflexes. Because reflexes do not require complex neuronal processing, but pain does, demonstrating reflex responses to noxious stimuli w...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-02-01
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| Series: | Animals |
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| Online Access: | https://www.mdpi.com/2076-2615/14/5/770 |
| _version_ | 1797264950638411776 |
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| author | Stuart Barr Robert W. Elwood |
| author_facet | Stuart Barr Robert W. Elwood |
| author_sort | Stuart Barr |
| collection | DOAJ |
| description | The suggestion that decapod crustaceans might experience pain has been dismissed by some authors who claim decapods only respond to noxious stimuli by nociceptive reflexes. Because reflexes do not require complex neuronal processing, but pain does, demonstrating reflex responses to noxious stimuli would not support the case for pain. Here, we report an experiment in which shore crabs are repeatedly placed in a light area (20 trials), but the animals can avoid the light by moving to a dark shelter. However, some crabs received an electric shock of 6 or 12 volts each time they entered the shelter. Those receiving either level of shock swiftly reduced their use of shelters and remained in the light. However, the magnitude of shelter avoidance was influenced by the brightness of the arena and the intensity of the shock. Shelter use was subsequently reduced to a greater extent if the shock level was high and the light intensity low. That is, crabs traded their avoidance of shock for their avoidance of bright light. Further, these animals showed avoidance learning and demonstrated activities suggesting anxiety, such as contact with the tank wall in the light area and increased latency to enter shelters when making the decision to enter the shelter if they had received shock in earlier trials. These results fulfil three key behavioural criteria for pain and, thus, are consistent with the idea that decapods can experience pain. |
| first_indexed | 2024-04-25T00:37:03Z |
| format | Article |
| id | doaj.art-ecd3a4ad072e48dc8b6aba9efb3b4e41 |
| institution | Directory Open Access Journal |
| issn | 2076-2615 |
| language | English |
| last_indexed | 2024-04-25T00:37:03Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Animals |
| spelling | doaj.art-ecd3a4ad072e48dc8b6aba9efb3b4e412024-03-12T16:38:15ZengMDPI AGAnimals2076-26152024-02-0114577010.3390/ani14050770Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of PainStuart Barr0Robert W. Elwood1School of Biological Sciences, Queen’s University, Belfast BT9 5DL, UKSchool of Biological Sciences, Queen’s University, Belfast BT9 5DL, UKThe suggestion that decapod crustaceans might experience pain has been dismissed by some authors who claim decapods only respond to noxious stimuli by nociceptive reflexes. Because reflexes do not require complex neuronal processing, but pain does, demonstrating reflex responses to noxious stimuli would not support the case for pain. Here, we report an experiment in which shore crabs are repeatedly placed in a light area (20 trials), but the animals can avoid the light by moving to a dark shelter. However, some crabs received an electric shock of 6 or 12 volts each time they entered the shelter. Those receiving either level of shock swiftly reduced their use of shelters and remained in the light. However, the magnitude of shelter avoidance was influenced by the brightness of the arena and the intensity of the shock. Shelter use was subsequently reduced to a greater extent if the shock level was high and the light intensity low. That is, crabs traded their avoidance of shock for their avoidance of bright light. Further, these animals showed avoidance learning and demonstrated activities suggesting anxiety, such as contact with the tank wall in the light area and increased latency to enter shelters when making the decision to enter the shelter if they had received shock in earlier trials. These results fulfil three key behavioural criteria for pain and, thus, are consistent with the idea that decapods can experience pain.https://www.mdpi.com/2076-2615/14/5/770paindecapod<i>Carcinus maenas</i>trade-offavoidancelearning |
| spellingShingle | Stuart Barr Robert W. Elwood Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain Animals pain decapod <i>Carcinus maenas</i> trade-off avoidance learning |
| title | Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain |
| title_full | Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain |
| title_fullStr | Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain |
| title_full_unstemmed | Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain |
| title_short | Trade-Offs between Avoidance of Noxious Electric Shock and Avoidance of Bright Light in Shore Crabs Are Consistent with Predictions of Pain |
| title_sort | trade offs between avoidance of noxious electric shock and avoidance of bright light in shore crabs are consistent with predictions of pain |
| topic | pain decapod <i>Carcinus maenas</i> trade-off avoidance learning |
| url | https://www.mdpi.com/2076-2615/14/5/770 |
| work_keys_str_mv | AT stuartbarr tradeoffsbetweenavoidanceofnoxiouselectricshockandavoidanceofbrightlightinshorecrabsareconsistentwithpredictionsofpain AT robertwelwood tradeoffsbetweenavoidanceofnoxiouselectricshockandavoidanceofbrightlightinshorecrabsareconsistentwithpredictionsofpain |