Chapter 2167: Chapter 1425: New Discovery (2)
"We need more evidence," Yang Ping said. "Immunohistochemistry, in situ hybridization, single-cell sequencing. We need to see what type of these newly emerged cells are. Are they neurons or glial cells? Excitatory or inhibitory? Are the synaptic connections they form functional or random? These questions need answering."
"I know."
"How long do you need?"
"If all the technical platforms are in place, two months."
"Go ahead."
Manstein looked up at Yang Ping, "Alright."
For the next two months, Manstein practically lived in the laboratory.
He cut the spinal cord tissue of M8 into thousands of tissue sections, staining each with different antibodies. He scanned each one using a confocal microscope, stacking the images into three-dimensional reconstruction models. He extracted tissues from the damaged area for single-cell sequencing, finding hundreds of cells with transcriptional profiles completely different from normal tissue out of tens of thousands of cells.
Data accumulated bit by bit, and every new piece of the puzzle pointed in the same direction.
The first piece of the puzzle came from immunohistochemistry. The newly emerged cells expressed a protein called doublecortin, a specific marker for migrating neuronal precursor cells. They didn’t exist in M8’s spinal cord before the injury, nor in the untreated control group animals, only in the experimental group animals that received intervention, specifically around the damaged areas. This indicates that these cells did not preexist but appeared after the intervention.
The second piece of the puzzle came from in situ hybridization. Those cells not only expressed doublecortin but also a transcription factor called NeuroD, an early marker of neural differentiation. They were differentiating from a stem cell state to a neuron state — not a matter of one or two days, but something that had been happening over the past few months. This was a dynamic process, not a one-time outbreak, but a continuous, organized, and directional differentiation process.
The third piece of the puzzle came from electron microscopy. Manstein stayed up late taking hundreds of electron microscope photos, in which newly generated neurons extended axons, clearly forming synaptic connections with downstream target cells. Not chaotic, random connections but organized, functional, and correctly directed connections. The synaptic cleft was about 20 nanometers, the presynaptic membrane had a clear aggregation of vesicles, and the postsynaptic membrane had a dense zone — all structural features of a typical, functional chemical synapse were present.
The fourth piece of the puzzle came from single-cell sequencing. Those hundred transcriptionally abnormal cells could be clearly divided into three groups: one in the stem cell state, one in the early neuronic differentiation, and one already differentiated into mature neurons. They constituted a complete lineage — from original cells to new neurons, every step was in the data. This was not a static tissue section; it was a movie in progress, with each frame captured by Manstein.
Manstein compiled all the data into a report, printing only two copies this time. One for Yang Ping, and one for himself.
After reading the report, Yang Ping placed the file on the desk, took off his glasses, and rubbed the bridge of his nose.
"Manstein, do you know what this means?"
"I know! Three-dimensional guided gene intervention is smarter than we thought. The human body is truly amazing."
"We are not repairing nerves; we are repairing the method itself. Neural regeneration is an old concept from decades ago, with everyone thinking about how to make axons grow faster, longer, and more accurately. We bypassed this issue and don’t need axons to grow very long because we built a new relay station at the injury site. Signals transmit from upstream neurons to the relay station, then from the relay station to downstream neurons, bypassing the damaged area. We originally thought our new method was only feasible for fresh injuries; now it seems it might work even for chronic injuries. The most amazing part is that we could even see some scar tissue dissolving, with original cells replacing these scar cells. This means our method not only adds by increasing new neurons but also subtracts by clearing obstacles to regeneration by removing glial scars. The addition and subtraction naturally amplify the effect."
Manstein leaned back in his chair, looking at the ceiling. He recalled the time he first read Yang Ping’s paper in the German laboratory. Back then, he had only one thought: if what this Chinese person said were true, it would change everything. Now sitting in the laboratory in China, looking at Yang Ping’s face, he was thinking another thought: what this Chinese person said was indeed true, not only true but also deeper than he initially understood.
"Professor, we should publish a new paper. In Nature or Science, to present this discovery. But I haven’t figured out exactly what it is I’ve discovered; I need to organize it well."
Yang Ping thought for a moment, then shook his head.
"No, don’t rush. First complete Chen Jianguo’s human trials. If this discovery is validated in him, it implies that M8’s results are not a primate-specific exception but replicable in humans. Then, publishing the paper will have more comprehensive data and a stronger persuasive power."
Manstein was silent for a long time.
"I need to reanalyze Chen Jianguo’s data. Once the data is out, we’ll write the paper."
"Okay."
Throughout the following week, Manstein’s mind was constantly occupied with the red cells on the tissue sections, those undergoing division, differentiation, and connection. He thought about them while walking, eating, and bathing. One night he suddenly sat up in bed, startling August.
"What’s wrong?"
"I am thinking about a question. If original cell repair can achieve such an advanced level, then in our previous animal experiment, how did the untargeted intervention group’s monkey recover? We didn’t perform precise genetic regulation on it, just made a broad microenvironment adjustment, yet it also stood up."
Manstein turned on the bedside lamp and picked up the notebook next to the bed, starting to jot down his recent thoughts.
After finishing, he closed the notebook, turned off the light, and lay there in the dark, thinking about the monkey called ’Surprise.’ How is it now? Could it also be reconnecting its spinal cord through original cell repair? It doesn’t know such a significant discovery has occurred within it. It just stood up and continued to stand.
The next morning, the first thing Manstein did upon reaching the laboratory was to find Fritz.
"Fritz, M21—"
"Surprise?" Fritz looked up at him.
"Yes! Is its spinal cord tissue still here?"
Fritz thought for a moment. After the experiment, the monkey was euthanized, and the tissue samples were preserved according to protocol.
"In the low-temperature freezer, the tissue sections are not all done; there are still some wax blocks."
"Take them all out. I want to redo the staining using a new marker. What about M8?"
"Its spinal cord was sectioned by you and is now paralyzed, needing care."
Fritz didn’t ask why. He put down the records he was holding and turned to the low-temperature freezer room. Manstein stood in the animal room, looking at M7’s cage. M7 was lying in the cage basking in the sun, its eyes squinting. He squatted down and gently touched M7’s head through the bars of the cage.
"M7, do you know? Now only you are walking. Don’t worry, one day M8 will be like you."
M7 opened its eyes, looked at him for a moment, then extended a hand through the bars, placing it on Manstein’s wrist. Its fingers were cold, with little grip, but they grasped precisely. Manstein did not move, just let that hand rest on his wrist.
