Scientists map neural network in mouse brain

Chinese scientists have outlined the largest depiction so far of mouse cells in the hippocampus, a key brain area for learning and memory, and studied how single neurons in the area are interconnected and how they connect with neurons in other brain areas.

The breakthrough may provide insights into further study of the functions of hippocampal neurons and the prevention and treatment of related diseases.

A paper about the study was published on the website of US-based journal Science on Friday.

Scientists explained that the hippocampus not only plays a crucial role in learning and memory, especially short-term memory, but also provides brain functions such as context and spatial cognition, navigation, stress responses and emotional behaviors.

To realize such functions, hippocampal neurons broadcast signals to other neurons in nearby or distant areas extensively throughout the brain.

"For example, the earliest manifestation of Alzheimer's disease in the brain is the death of cells in the hippocampus and their abnormal connections. This research may pave the way for a better understanding of various brain disorders," said Poo Muming, an academician with the Chinese Academy of Sciences and director of academics at the Center for Excellence in Brain Science and Intelligence Technology, CAS.

The study was led by the center, in collaboration with institutions including the Suzhou Institute of Neurospatial Information of Huazhong University of Science and Technology, Hainan University, CAS' Kunming Institute of Zoology, the Lingang Laboratory and the Shanghai Center for Brain Science and Brain-inspired Technology.

In their research efforts, scientists employed a wide range of tools to analyze the entire neural roadmap.

They reconstructed a map of 10,100 single neurons in the hippocampus in mice, and classified 43 neural projection patterns.

"Such previously unknown spatial organization principles of single neuron projections will provide a structural basis for a better understanding the function of hippocampal neurons," said Xu Chun, a leading researcher on the team and a correspondent author of the paper.

"This enormous dataset (in the paper) provides unprecedented insights into the divergence of hippocampal output, bilateral projections and some of the principles of hippocampal projections at the level of individual neurons," said one peer review.

Poo said the research results will provide a foundation to work out a function map of the single neurons in the mouse hippocampus to discover how signals are transmitted and which single neurons and signals are related to particular brain functions, such as memory, learning and emotions.