Scopolamine Effects Under a Titrating-Delayed-Nonmatching-to-Position Procedure

Abstract

In a study of working memory, the performance of rats under titrating-delayednonmatching- to-position (TDNMTP) procedures was examined. Overall accuracy and the number of trials completed were inversely related to titration value, whereas the highest delay attained was directly related to titration value. When given intraperitoneally, scopolamine significantly reduced the highest delay attained without significantly affecting other performance measures for most administrations. Subcutaneous administrations significantly reduced all performance measures, suggesting that, as in most prior studies, the drug’s disruptive effects were not limited to memory processes. These findings demonstrate the feasibility of using TDNMTP procedures with rats, but further research is necessary to determine if such procedures are especially valuable in studying working memory and drug effects thereon.

Full text

scoPolaMiNe eFFecTs UNdeR a TiTRaTiNg-delayed-
NoNMaTchiNg-To-PosiTioN PRocedURe

Western Michigan University
In a study of working memory, the performance of rats under titrating-delayed-
nonmatching-to-position (TDNMTP) procedures was examined. Overall accura-
cy and the number of trials completed were inversely related to titration value,
whereas the highest delay attained was directly related to titration value. When
given intraperitoneally, scopolamine significantly reduced the highest delay
attained without significantly affecting other performance measures for most
administrations. Subcutaneous administrations significantly reduced all perfor-
mance measures, suggesting that, as in most prior studies, the drug’s disruptive
effects were not limited to memory processes. These findings demonstrate the
feasibility of using TDNMTP procedures with rats, but further research is neces-
sary to determine if such procedures are especially valuable in studying working
memory and dr ug effects thereon.
    
        

   
               


     




      



          
 
         
       
                      




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        
       
        
             
      


 


        
     
              






      

         

        



      

 
    
           


    
            


   
            
         
         
           
             




       
        
               

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

       
    

          

                
           
     
              

          

     




  
         
        
              


   
   
       
        

       


            


  
  
    
  
           
              



Subjects
        
 


40

         
       
×× 

   

           

Guide for the Care and Use of Laboratory Animals

Apparatus
       
     ×    ×     
     
     

       

       



        


Behavioral Procedure
 
    
                  

 

               




              

   


                
              

           

41

  
             

             


     






Pharmacological Procedure


  

         
  
   

  
            
  


         
        
                  





Data Analysis
         
          


              
p

              
          
  


42
    




    
       


×Fp
F
       

   
 
   
   
      
        
   F   
p

      
     
   

    

    
    
     
   
      
     
   
    
     
   
        
  F   
pF
p
       
    F
   p     

    
     

       
    
Figure 1. Mean (± standard error of
mean) overall accuracy (percentage of
correct responses), number of trials
completed, and highest delay reached
by 7 rats during baseline (no injection)
and vehicle-control sessions. Rats were
exposed to four variations of a TDNMTP
procedure, with the variations defined
in terms of the length of the titration
interval, which is indicated.
Titration Value

43


   

   
    



  
    
   
    
   




  
Fp
F  p 
    
   
Fp
    

    
    
    



     
    
  
    
   
  F   
p      
F p  
  
  
  F
p



  




Figure 2. Ef fects of scopolamine on overall
accuracy, trials completed, and highest delay
reached. Data during sessions in which the
indicated dose of drug was given are expressed
as a percentage of vehicle control (see Figure 1).
All doses were given intraperitoneally (IP) except
for the indicated .06 mg/kg subcutaneous (SC)
dose. Asterisks indicate doses where the drug
mean differed significantly (p < .05) from the
vehicle-control mean.


44
              
  
     



Figure 3. Effect sizes (Cohen’s D) for the highest delay reached, by dose of scopolamine.
Data are presented separately for each of the four titration values. IP = intraperitoneal;
SC = subcutaneous.
    





         
             
                
            
            
       
                
            
     
                 
           
   

       
       

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





               

           
               







         


      
      


        





         


         
       
            



   
       

          






   
           
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 
 


      
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
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

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      
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
           


          
         
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

    




 
        


          
x
y       
          
         
       


 



47

        
 




Figure 4. Mean values for the highest delay reached when the 0.06 mg/kg subcutaneous
(SC) dose of scopolamine was administered and in the immediately prior vehicle-control
sessions when the same number of trials are considered. Data are presented for each
of the four titration values.
           
        









            
              


 

         
      
        
      





Psychopharmacology


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


Psychopharmacology





Journal of
Pharmacology and Experimental Therapeutics



Psychopharmacology
 



European Journal of Pharmacology



Behavioural Brain Research
 


European
Journal of Neuroscience


Behavioural Brain
Research
  



Proceedings of the National Academy
of Sciences of the United States of America


Guide for the care
and use of laboratory animals



Pharmacology Biochemistr y and Behavior



Progress in
Neuro-Psychopharmacology and Biological Psychiatry



Journal of Pharmacological
and Toxicological Methods




Neurotoxicology and
Teratology



49
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
Journal of the Experimental Analysis of Behavior




Journal of Pharmacology and Experimental Therapeutics



Introduction to behavioral pharmacology




Behavioural Processes






Behavioural Pharmacology




Brain Research



Behavioural Brain Research




Psychopharmacology



Psychopharmacology



Journal of Pharmacology and Experimental Therapeutics

 


Journal of Experimental Psychology: Animal Behavior
Processes




Behavioral Neuroscience



American Journal of Mental
Deficiency