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The effect of prenatal morphine exposure on memory consolidation in the chick
1Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, PR China.
Insights
Prenatal morphine exposure in chicks impairs long-term memory formation. This study investigated how early-life drug exposure affects learning and memory development in young birds.
Area of Science:
- Neuroscience
- Developmental Biology
- Pharmacology
Background:
- The developing central nervous system shows significant plasticity.
- Prenatal exposure to substances like morphine can alter neurodevelopment.
- Previous research suggests prenatal morphine exposure may impact learning and memory.
Purpose of the Study:
- To investigate the effects of prenatal morphine exposure on learning and memory deficits in chicks.
- To evaluate the impact on different memory phases: short-term memory (STM), intermediate-term memory (ITM), and long-term memory (LTM).
Main Methods:
- Morphine was administered to chicken eggs via airspace injection (20 mg/kg) daily from embryonic day 12 (E12) to E16.
- The one-trial passive avoidance learning paradigm was employed to assess memory consolidation in 1-day-old chicks.
Main Results:
- Chicks exposed to prenatal morphine showed significantly impaired long-term memory (LTM) 120 minutes after training (p<0.001).
- No significant impairment was observed in intermediate-term memory (ITM) at 30 minutes after training.
Conclusions:
- Prenatal morphine exposure during critical developmental periods can lead to lasting deficits in long-term memory consolidation.
- The chick model provides a valuable tool for studying the neurobiological mechanisms underlying drug-induced memory impairments.
Abstract:
The central nervous system exhibits remarkable plasticity in early life and can be altered significantly by prenatal morphine exposure. Previous studies show that prenatal morphine exposure may alter the capacity for learning and memory in post-partum chicks. The one-trial passive avoidance learning paradigm with 1-day-old chicks is an excellent model to study several mechanisms of memory formation, including STM, ITM, and LTM. The following represents our investigation of the effect of prenatal morphine exposure on learning and memory deficits in the chick. In these experiments, morphine was injected into the airspace of eggs (20 mg/kg) and the one-trial passive avoidance learning paradigm was used to test the effect of prenatal morphine exposure on memory consolidation. The data suggest that chicks injected with morphine daily from E12 to E16 had significantly impaired long-term memory at 120 min after training (p<0.001) but not intermediate-term memory at 30 min after training.
