RT Journal
A1 McKhann GM
T1 Neurobiology: Mind and matter
JF American Journal of Diseases of Children
JO American Journal of Diseases of Children
YR 1969
FD December 1
VO 118
IS 6
SP 830
OP 835
DO 10.1001/archpedi.1969.02100040832005
UL http://dx.doi.org/10.1001/archpedi.1969.02100040832005
AB IN THIS discussion I have chosen to sample the burgeoning field of neurobiology in an attempt to relate this field to clinical problems of the developing nervous system. Before doing that, I shall consider some of the present concepts about the nervous system, and question whether they will hold up over the coming years.One of the questions concerns the concept that the development of the nervous system is a carefully programmed event, with little room for variation and little flexibility. I should like to question this concept in terms of the criteria listed below:Stages of Neuronal DevelopmentNeuronal formation First trimesterNeuronal migration Second trimesterNeuronal interconnection Third trimester and PostnatalMyelin formation PostnatalNeuronal Formation 
    There is considerable evidence that the concept of a specific time for neuronal formation is too rigid. On the contrary, there are neurons which continue to form during fetal development, and, in