Body Electric etc. - unresolved questions

In Body Electric, Dr.Robert Becker deduced that salamanders' limbs regenerate efficiently due to higher concentration of nerves in their extremities,

if so, then...

why don't HUMAN brains & eyes regenerate efficiently due to the high density of nerves in peoples' cranial area?

Another (related) loose end:

In the stem cell book Proteus Effect, Ms.Parson cited various researchers who used cultures such as coconut milk, vitamins, minerals to ensure the continuity of stem cells. Then later on she states that researchers found that salamanders with severed limbs regenerated despite not being fed.

Question:

How to reconcile this contradiction?

Is it that vitamins/minerals are interchangable with the highly efficient pulsed EMFs that salamander limbs have?

Also - on pg. 210, an "eminent ophthamologist" (Adler) warned scientists it's not likely that signalling molecules will be in the right place at the right time for stem cells to see, upon transplanting them to the retina.

Apparently, stem cell authors & researchers ignore Dr. Rob Becker's research in Body Electric re: accelerating blastocyst formation via pulsed EMFs. Tweet