Abstract of a paper describing an electroporation protocol optimized for Xenopus tadpole brains:

Bestman JE, Ewald RC, Chiu SL, Cline HT. In vivo single-cell electroporation for transfer of DNA and macromolecules. Nat Protoc. 2006;1(3):1267-72.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=17406410