380 



BRAIN MECHANISMS AND LEARNING 



B 



Fig. 5 

 Dissection of rabbit brain to illustrate features of the c.xCra-callosal isolation. A slab of cerebral 

 cortex in the hemisphere opposite the ethyl chloride lesion is dissected so that the cortex is 

 separated from all subcortical connections and from the surrounding intracortical regions as 

 well. The callosal pathway remains intact and is the only connection through which input is 

 available to the dissected region (5A). In a Weil stained cross section (5B) the integrity of the 

 callosal pathway may be visualized. For photography the cortex was lifted to demonstrate 

 the underlying white matter but the operative procedure, of course, is done in such a way as 

 to preserve the pial circulation to the cortical slab. 



