NO. 77

Time:

Thursday, Jun. 26 2025, 3:00 p.m.

Location:

Multi-Function Hall, 2nd Floor, North Basic Research Building 

Host：

Zhiqiang Yan (闫致强)

Chinese Institutes for Medical Research, Beijing

Speaker：

Xu Zhang (张旭)

Professor

Guangdong Institute of Intelligence Science and Technology

TITLE：

Neural Network of Pain

ABSTRACT:

Nociceptive signals are transmitted to the somatosensory cortex via the spinothalamic-thalamocortical pathway. Recently, the neuron types of dorsal root ganglion (DRG) have been identified. However, the spinal ascending pathways and the neural networks derived from these neuron types in the brain need to be revealed.

Using single-cell RNA sequencing, we identified 17 neuron types in the DRG, and their transcriptional states in physiology and chronic pain after peripheral nerve injury. Furthermore, we achieved tracing of neural networks derived from specific types of nociceptors or pruriceptors. By comparing neural networks derived from galanin-containing nociceptors and neurotensin-expressing pruriceptors, we identified differentially labeled nuclei, reveal distinct organization of ascending pathways, and demonstrated different involvement of the somatic motor system and the emotional motor systems in two neural networks. We also found that a subset of layer 5 neurons in somatosensory cortex receives spinal inputs through a direct spino-cortical circuit bypassing the thalamus, and thus define these neurons as spino-cortical recipient neurons (SCRNs). The branches from spinal ascending axons formed a kind of disciform structure with the descending axons from SCRNs in the basilar pontine nucleus (BPN). The axon terminals from spinal ascending neurons and SCRNs made functional synaptic contacts, linking ascending sensory pathway to descending motor-control pathway. The spino-cortical connection was involved in nociceptive responses.

Furthermore, we studied the human DRG neuron types in development. A human-enriched DCC+/NTRK3+ nociceptor was identified. We also study the aging of DRG, and found the changes in both the cells in aged DRGs and the somatosensory functions.

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