30 



Survey of Neurobiology 



the symposium is illustrated by the follow- 

 ing sample quotations. 



"While some hopeful beginning in the analysis 

 of this complieated process (i.e., the development 

 of the nervous system ) has been made, most of 

 the work remains yet to be done . . . The analyti- 

 cal concept of nerve development lends itself to 

 attack by the methods of analytical experimentation 

 and deserves, therefore, a high rating. It leads 

 to concrete experiments, and we have hardly be- 

 gun to exploit its vast possibilities" ( Harrison ) . 



"In reviewing the field of neuroembryology, 

 one is impressed by the scarcity of factual infor- 

 mation, and also by the failure to exploit fully 

 the opportunities offered by the experimental em- 

 bryological methods and techniques for neurologi- 

 cal and behavior problems . . . The embryologist 

 is not sufficiently informed in neurological details 

 and methods and he usually lacks the conceptual 

 approach of the behaviorist. The only hope for a 

 fruitful progress lies in his cooperation with men 

 trained in neighboring fields" (Hamburger). 



"The study of the nerve cell during its em- 

 bryonic development is not only of great theoreti- 

 cal interest but is also an important tool in the 

 analytic fractionation of the complex structures 

 and functions of the mature cell. Technical dif- 

 ficulties of such analysis are reflected in the fact 

 that this field is still almost virgin with respect 

 to biochemical or histochemical studies which 

 might illuminate the spectacular morphological 

 changes which separate the neuron from the neu- 

 roblast ... It is obvious that this field is wide 

 open for further investigation, and that in ad- 

 dition to the general problems of cell growth and 

 differentiation, many practical problems, such as 

 the regeneration of injured nervous tissue and 

 the action of neurotropic viruses or of neurotoxic 

 drugs await the understanding which might come 

 from such investigations" (Bodian). 



"Data of considerable volume exist on various 

 chemical entities in the developing nervous 

 system, but for the most part, they represent iso- 

 lated observations, and it is well nigh impossible 

 to correlate these into a comprehensive picture 

 for even one animal. Systematic studies on the 

 chemical growth of the nervous system in the 

 embryo and fetus are practically non-existent, a 

 fact which is the more unfortunate since it would 

 seem logical to assume that having more informa- 

 tion on the order of appearance and the growth 

 of various chemical constituents and metabolic 

 events in the developing nervous system could 

 not fail to contribute to our understanding of the 

 subtle physiological changes associated with func- 



tional maturation of tlic nervous system . . . 

 What is clearly needed, in addition to an ap- 

 preciation of the very great amount of useful in- 

 formation which can be obtained from st\idics on 

 metabolic processes in isolated tissues and tissue 

 homogenates, is a clear realization of tlie limita- 

 tions inherent in such studies in providing an in- 

 sight into the way metabolic processes arc regu- 

 lated and ordered in the intact cell or organism. 

 This necessitates a consideration of the importance 

 of mechanisms which regulate the intensity and 

 direction of chemical processes in the nerve cell. 

 In this field ignorance is almost complete" (Boell), 



The questionnaire (appendix B) was 

 sent out to the 61 most prominent investi- 

 gators in genetic neurology. Of the 51 

 persons who sent detailed replies, 36 de- 

 scribed the state of the field as "unsatis- 

 factory," 3 as "satisfactory," and 4 were 

 "undecided." The following were given as 

 presumable reasons for the "unsatisfactory" 

 condition (listed in the order of weight as- 

 signed to them by the group): lack of ex- 

 plicit formulation of the problems; lack of 

 trained personnel; lack of "appeal" and 

 emphasis in current teaching programs; 

 lack of funds. Only a minority mentioned 

 administrative difficulties (e.g., lack of time 

 or of facilities for cooperative worx), or 

 lack of publication facilities. Asked for the 

 existence of courses dealing wholly or in 

 part with genetic neurology, 24 replies (ex- 

 cluding institutional overlap ) reported com- 

 plete lack of such courses, 5 indicated some 

 mention of the subject in general courses, 

 leaving only 6 institutions with an oc- 

 casional graduate course, and 7 with sem- 

 inars, devoted to some problems of genetic 

 neurology. 



In order to test the degree of community 

 among the workers in the field, the follow- 

 ing question was asked: "How many uni- 

 versity departments and research institutes 

 in this country could you name in which 

 genetic neurology receives systematic (i.e., 

 more than casual) investigation?" Of 27 

 answers received to this question (table, 

 appendix B, 5), 23 referred to fewer 

 than 15, and 17 to fewer than 10 places en- 

 gaged in such activities. These figures 

 are quantitative supplements to the desig- 

 nation of the state of the field as "inade- 

 quate." 



