🇺🇸 영어 원문
The hippocampus plays a central role in how we form memories and navigate space. It helps convert short-term experiences into long-term memories, allowing us to store and build on what we learn. Scientists led by Magdalena Walz Professor for Life Sciences Peter Jonas at the Institute of Science and Technology Austria (ISTA) are closely studying this brain region. Their new research, published in Nature Communications, explores how one of the hippocampus’s main neural networks develops after birth.
Picture a completely empty sheet of paper. You begin writing on it, gradually filling it with information. This idea reflects the concept of tabula rasa, or the “blank slate.”
Now imagine a page that already has marks on it. Any new information must fit around or replace what is already there. This represents tabula plena, or the “full slate.”
This long-standing debate asks whether we begin life with everything prearranged or whether our experiences shape who we become. In biology, this question appears as the balance between genetic instructions and environmental influences that shape development.
The research team at ISTA applied this idea to the hippocampus, which is responsible for memory and spatial awareness. They wanted to understand how its internal network changes after birth and whether it behaves more like a blank slate or a full one.
Studying the Brain’s Memory Network
The scientists focused on a key hippocampal circuit made up of CA3 pyramidal neurons. These cells are critical for storing and retrieving memories. They rely on plasticity, the brain’s ability to adapt by strengthening or weakening connections or by altering structure.
ISTA alum Victor Vargas-Barroso studied mouse brains at three stages of development: early after birth (day 7-8), adolescence (day 18-25), and adulthood (day 45-50).
To examine how these networks function, he used the patch-clamp technique, which measures tiny electrical signals within specific parts of neurons, including presynaptic terminals and dendrites. The team also used advanced imaging and laser-based methods to observe activity inside the cells and to activate individual neural connections with precision.
From Dense and Random to Refined and Efficient
The findings revealed a surprising pattern. Early in development, the CA3 network is extremely dense, with connections that appear largely random. As the brain matures, this network becomes less crowded but more organized and efficient.
“This discovery was quite surprising,” says Jonas. “Intuitively, one might expect that a network grows and becomes denser over time. Here, we see the opposite. It follows what we call a pruning model: it starts out full, and then it becomes streamlined and optimized.”
Why the Brain Starts Full
Researchers are still exploring why this pattern occurs. Jonas suggests that beginning with a highly connected network may allow neurons to link up quickly, which is especially important in the hippocampus. This region must combine different types of information, including sights, sounds, and smells, into cohesive memories.
“That’s a complex task for neurons,” Jonas explains. “An initially exuberant connectivity, followed by selective pruning, might be exactly what enables this integration.”
If the brain started as a true tabula rasa, with no built-in connections, neurons would first need to locate and connect with one another. That process could slow communication and reduce efficiency, making it harder to form memories effectively.
Overall, the findings suggest that the brain begins not as a blank slate, but as a richly connected network that becomes more precise over time by trimming away unnecessary links.
🇰🇷 한국어 요약
뇌의 기억 중추인 해마는 태어날 때 비어있는 상태가 아니라 오히려 과도하게 연결된 상태에서 시작한다는 연구 결과가 나왔습니다. 오스트리아 과학기술연구소 (ISTA) 연구팀은 해마의 CA3 신경 회로가 출생 직후에는 매우 밀집되고 무작위적으로 연결되어 있지만, 성장하면서 불필요한 연결을 제거하며 정교하고 효율적인 네트워크로 발달한다는 사실을 발견했습니다.
이러한 “가지치기 (pruning)” 과정을 통해 뇌는 다양한 정보 (시각, 청각, 후각 등) 를 통합하여 일관된 기억을 형성할 수 있게 됩니다. 만약 뇌가 처음부터 완전히 비어있었다면, 신경세포들이 서로 연결을 찾느라 시간이 많이 걸리고 기억 형성 효율이 떨어졌을 것입니다.
이 연구는 뇌 발달이 “비워진 서판 (tabula rasa)” 모델이 아니라 “가득 찬 서판 (tabula plena)” 모델에 더 가깝다는 것을 보여주며, 기억과 학습 메커니즘에 대한 새로운 이해를 제공합니다.
🔑 핵심 단어 (Vocabulary)
- Hippocampus – 해마 – The hippocampus plays a central role in how we form memories.
- Neural network – 신경 회로 – Researchers studied how the neural network develops after birth.
- Plasticity – 가소성 – The brain relies on plasticity to adapt by strengthening or weakening connections.
- Pyramidal neurons – 피라미드 신경세포 – CA3 pyramidal neurons are critical for storing and retrieving memories.
- Pruning – 가지치기 – The pruning model suggests the brain starts full and becomes streamlined.
- Tabula rasa – 비워진 서판 (백지상태) – The concept of tabula rasa suggests we begin life with a blank slate.
- Tabula plena – 가득 찬 서판 – Tabula plena represents the idea that the brain starts with existing connections.
- Cognitive function – 인지 기능 – The brain’s efficiency affects cognitive function and memory formation.
- Synaptic connectivity – 시냅스 연결성 – Synaptic connectivity becomes more organized as the brain matures.
- Integration – 통합 – The brain must integrate different types of information into cohesive memories.
🔗 원문 링크
https://www.sciencedaily.com/releases/2026/05/260501052842.htm