DeepSummary
The podcast discusses research on 'infantile amnesia' - the inability to recall memories from early childhood. Freelance journalist Sarah Reardon explains potential reasons for this phenomenon, including theories about the developing brain suppressing early memories to make room for new ones. She discusses experiments tracking memory development in infants and young children, as well as studies in mice that use optogenetics to manipulate memory formation.
Reardon also talks about how understanding infantile amnesia could have implications for early childhood education and care, as well as insight into memory loss in conditions like Alzheimer's disease. In the second part, researcher Hui Kwan Lee discusses his research on how the brain encodes 'generalized fear' - a symptom of anxiety disorders where fear responses occur without specific triggers.
Lee's work in mice found that after a stressful event, neurons in a midbrain region called the dorsal raphe switch from releasing the neurotransmitter glutamate to GABA. This switch correlated with the onset of generalized fear behavior, and preventing the switch blocked generalized fear in mice. Lee also found evidence of this neurotransmitter change in postmortem brain samples from people with PTSD.
Key Episodes Takeaways
- Infantile amnesia may result from the developing brain suppressing or overwriting early memories to focus on forming generalizations.
- Animal studies using techniques like optogenetics are providing insight into potential brain mechanisms behind infantile amnesia.
- Understanding infantile amnesia could have implications for early childhood education and care.
- Mice studies found that after acute stress, neurons in the midbrain switch from releasing glutamate to GABA, correlating with generalized fear.
- Similar neurotransmitter changes were observed in human PTSD brain samples, suggesting a role in generalized fear/anxiety symptoms.
- Administering Prozac shortly after a stressful event blocked the onset of generalized fear in mice, but had no effect weeks later.
- The research points to promising new therapeutic targets for treating anxiety disorders involving generalized fear.
- Critical periods of high brain plasticity in early life may underlie phenomena like infantile amnesia and language acquisition.
Top Episodes Quotes
- “We observed neurotransmitter changes in a brain region called dorsal raphe, that is, in the midbrain. And we observed that the serotonergic neurons in this region changed their co-transmitter from glutamate into GABA.“ by Hui Kwan Lee
- “When we block neurogenesis, then they also seem to block infantile amnesia.“ by Sarah Reardon
- “When we provide Prozac immediately after the foot shot, two weeks later, the generalized fear was gone, was not observed for these mice. But when we provided Prozac two weeks after the food shock, when the fear response is already produced, there was no effect.“ by Hui Kwan Lee
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Episode Information
Science Magazine Podcast
Science Magazine
3/14/24
Investigating “infantile amnesia,” and how generalized fear after acute stress reflects changes in the brain
This week we have two neuroscience stories. First up, freelance science journalist Sara Reardon looks at why infants’ memories fade. She joins host Sarah Crespi to discuss ongoing experiments that aim to determine when the forgetting stops and why it happens in the first place.
Next on the show, Hui-Quan Li, a senior scientist at Neurocrine Biosciences, talks with Sarah about how the brain encodes generalized fear, a symptom of some anxiety disorders such as social anxiety and post-traumatic stress disorder.
This week’s episode was produced with help from Podigy.
Authors: Sarah Crespi; Kevin McLean; Sara Reardon
Episode page: https://www.science.org/doi/10.1126/science.z9bqkyc