Chapter \^ 



Silver 

 Impregnation II 



NEUROLOGICAL TECHNICS 



Briefly, the neurological elements may be grouped as follows: 



1. Supporting elements; the neuroglial fibers and cells, also some con- 

 nective tisstie 



a. Astrocytes — support the neurons 



h. Oligodendroglia — help to form and maintain the myelin 



c. Microglia — part of the defense system of the nervous system 



2. Nerve cell bodies {neurons), including various cytoplasmic struc- 

 ttires 



a. Nissl's granules 



h. Neurofibrils, fine cytoplasmic fibers 



c. Mitochondria and Golgi (sometimes present; see p. 259) 



d. Melanin and lipofuscins (see p. 241) 



3. Nerve fibers (axons and dendrites) 



a. Myelin — a glistening fatty material that coats the axons in the 

 outer layer of the developing spinal cord 



4. Nerve endings 



a. Pericellular end bulbs, sensory 



b. Motor end plates 



When impregnating tissues from the central nervotis system certain 

 facts should be kept in mind. If the hydroxide method is used, astro- 

 cytes and microglia are not specially impregnated. If the carbonate 

 method is used, the opposite effect takes place. Use body temperature 

 fur impregnation, not hot sokitions. Eor nervous tisstie, frozen sections 



