The mammalian brain’s prefrontal cortex (PFC) is known to be involved in decision-making, planning, complex social behavior, and integrating other brain regions’ activity. Numerous neuroscience studies have examined the function and structure of this crucial brain region, but little is known about how its neurons are organized.
Dendrites, which are branches extending from neurons that receive impulses from other neurons, and axons, which are regions of neurons that generate and transmit impulses, are the subjects of recent research at the Chinese Academy of Sciences aimed at gaining a deeper comprehension of the PFC’s organization. They used a novel tool to map thousands of dendrites and axons in the mouse PFC in a recent paper that was published in Nature Neuroscience.
Jun Yan, one of the study’s authors, told Medical Xpress, “Our previous paper reconstructed the complete axons of more than 6,000 neurons in mouse PFC.” The dendrites of these neurons are also included in the same data. We thought it would be natural to reconstruct the dendrites of these neurons and investigate the relationship between axons and dendrites, as dendrite morphology defines the way neurons receive information.
“Our research has two major implications.” For starters, it demonstrates that a more thorough neuron classification should take dendrites and axons into account. Second, having both dendrites and axons available allowed us to better recreate a neuronal network.”
Jun Yan, one of the researchers who carried out the study,
The researchers used a tool they developed called “fast neurite tracer” (FNT) to conduct their new analyses using data from a previous study. This is essentially a software tool with a three-dimensional (3D) graphical user interface that can trace terabytes of images.
Yan explained, “We selected approximately 2,000 neurons with the best image quality of dendrites for complete reconstruction, and we analyzed the same data in which we previously traced axons.” After that, we looked at how these dendrites matched up with the classification based on axon projections for the same neurons and classified them according to their morphology.”
Yan and his colleagues were able to identify 1,515 neurons with pyramidal projection and 405 neurons with atypical pyramidal projection, also known as spiny stellate neurons with unusual axon projection patterns, through their analyses. They also gained new knowledge about how the projection neurons in the mouse PFC are organized. They showed that these neurons could communicate with neurons in the same column, with neurons in other columns, and with neurons in other parts of the brain, allowing neural information to flow in a particular way across the PFC.
According to Yan, “We identified both shared and divergent features between dendrite morphology and axon projection.” There are two major repercussions of our study. First, it demonstrates that dendrites and axons should be included in a more comprehensive classification of neurons. Furthermore, the accessibility of the two dendrites and axons permitted us to more likely reproduce a brain organization.”
A detailed reconstruction of the mouse PFC’s axons and dendrites is provided by this team’s recent findings, which may serve as a foundation for future neuroscience research and theoretical predictions. The current comprehension of the PFC of all mammals, including humans, could be enhanced as a result of this, as could the creation of new sophisticated computational tools inspired by the human brain.
Yan continued, “The next step of this study would be to learn the functions of the neural network and validate the neural network we reconstructed from dendrites and axons.” For instance, what can this PFC neural network teach us about the new artificial intelligence network design?”
More information: Le Gao et al, Single-neuron analysis of dendrites and axons reveals the network organization in mouse prefrontal cortex, Nature Neuroscience (2023). DOI: 10.1038/s41593-023-01339-y
