CHAPTER XL 



Neurosecretion' 



R. O R T M A N N j Anatomisches Inslitut, Frankfurt am Main, Germany 



CHAPTER CONTENTS 



Historical Introduction and Nomenclature 

 Neurosecretory Cells as Specialized Neurons 

 Neurosecretion in Vertebrates 



Hypothalamic-Pituitary System Demonstrable with Chrom- 

 hematoxylin 

 Morphology 

 Ontogeny 

 Histochemistry 

 Experimental studies 

 Functional relationships 

 Central Nervous System Neurosecretory Systems not Demon- 

 strated with Chromhematoxylin 

 Anterior hypothalamus 

 Tuber cinereum 

 Spinal cord 

 Neurosecretion in Peripheral Nervous System 

 Neurosecretion in Invertebrates 

 General Considerations 



Neurosecretory Activity in Various Classes of Invertebrates 

 Vermes 



Echinodermata 

 Mollusca 

 Arthropods 

 Insects 

 Conclusion 



HISTORICAL INTRODUCTION AND NOMENCLATURE 



THE FINDING of 'glaod-likc' cells in the spinal cord of 

 sharks by Dahlgren (75) and Speidel (305) consti- 

 tuted the first observations on secretory activity in 

 nerve cells. The investigators Collin, Scharrer, 

 Hanstrdm, Roussy and Mosinger are associated 

 with a period of research during which a large num- 



' English version prepared by K. M. Knigge, Department of 

 Anatomy, University of California, Los Angeles, from the 

 original German. The manuscript was completed February 5, 

 1956. 



ber of significant observations on the hypothalamus 

 and neurosecretion were accuinlated. To Ernst 

 Scharrer belongs the credit for having positively 

 demonstrated the secretory activity of special groups 

 of neurons. In collaboration with Berta Scharrer, he 

 led the research on neurosecretion to most fruitful 

 results. The work at this time, however, was some- 

 what restricted by the poor and nonspecific stain 

 techniques available. The introduction of the chrom- 

 heinatoxylin stain technique of Gomori represented a 

 key advance and permitted Bargmann (29) to lay the 

 true foundations for this field of investigation. Be- 

 cause the work on neurosecretion is at most 50 years 

 old, it is not surprising that its terms are not yet 

 strictly formulated and are not being uniformly used 

 by the workers involved. Scharrer's original 'hypo- 

 thalamus gland' and 'neurocrine organs' (279, 280) 

 have only historical significance today. 



The term neurocrinie (72) indicates the reception of 

 secretory material by nervous tissue. Therefore, it is 

 impossible to use it synonymously with neurosecre- 

 tion. Barry (39) has employed the term neurocrinie to 

 imply the concept of delivery of neurosecretory ma- 

 terial to nervous tissue, using for the region of transi- 

 tion the term synapse neurosecretoire. 



The term neuricrinie (268) has been used especially 

 by the workers of the French school as synonymous 

 with neurosecretion. Recently Barry (39) has pro- 

 po-sed to include in this term not only neurosecretion 

 but also the secretory activity of neuroglial structures, 

 such as the subfornical and subcommissural organs, 

 tlie supraoptic crest and possible pineal cells, and the 

 production of neurohorinones (208). 



Basic to the concept of 'neurosecretion' is the pres- 

 ence of true neurons with axons and dendrites, Nissl 

 substance and neurofibrillae. These cells also exhibit 

 morphologically demonstrable evidence of secretory 



■039 



