[Histonet] damage to dura

[Caroline Bass]

Hey guys,

i have a question I thought may be good for the group.  I am doing  
stereotax surgeries on rats, basically making lesions in the  
prefrontal cortex.  There are two potential sham controls, one where  
a vehicle is injected the other where the holes are drilled but  
nothing is injected.  So here's the problem.  In the no injection  
sham (i.e. only holes are drilled) the animals display an alteration  
of the behavior we're interested in.  The tissue looks good, and  
there is no sign of infiltration of immune cells in the PFC by cresyl  
violet.  However, the dura does have some damage where the drill  
pierced the skull.  We use a standard dremmel.

Are there any suggestions for what could be going on?  Is there an  
immune response we should specifically look for, or is there  
something else about the dura that could be affecting our system?   
Does anyone know of how dura damage can alter nearby brain areas?

Any and all advice is appreciated.

Caroline