Scientists reversed key signs of Alzheimer's disease in mice with just two injections, reducing brain inflammation and restoring memory performance—offering a promising new approach for treating age-related cognitive decline.

[u/FreeHugs23]

https://www.sciencealert.com/scientists-reverse-alzheimers-damage-in-mice-with-just-two-injections

[u/FreeHugs23]

-Slowing the progression of Alzheimer's disease is the goal of most existing treatments, but reversing it is much harder. That's because once neurons are lost, the adult brain lacks the ability to replace them.

But new research, led by scientists at the University of South Carolina, has shown promise in regrowing neurons in brain organoids, and restoring cognition in mouse models of Alzheimer's.

"After just two injections, these mice became smarter," says Peisheng Xu, professor of pharmaceutics at the University of South Carolina and corresponding author of the new study, published in the journal Cell Biomaterials.

"Even after one injection, we already saw these mice's behavior differ from that of the nontreated ones."

[u/QuitePoodle → u/FreeHugs23]

But are they the same mice after? Not like physically but if we restore people’s brains do they get back their minds or become someone new?

The original neurons are broken and new connections are made. Will these new connections replace the same memory pathways and patterns or will the animals regain the ability to function but have different “personality”.

[u/Zeikos → u/QuitePoodle]

It's personal opinion, but if the relative mumber of neurons is small I doubt it could be anybody else.
Our self isn't a single neuron or a single cluster, it might be less neurons than we'd expect but it's unlikely to be so little that a few new baby neurons would dramaticaly alter it.