Activity density in the open field: A measure for differentiating the effect of psychostimulants

Neri Kafkafi*, Gregory I. Elmer

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Traditional open-field activity measures do not provide a sharp behavioral differentiation across psychomotor stimulants such as d-amphetamine (AMPH) and cocaine (COC) in the mouse. We used Software for the Exploration of Exploration (SEE) to investigate and develop a novel behavioral endpoint to characterize the "structure" of AMPH- and COC-induced locomotor behavior in two inbred strains of mouse, C57BL/6 (B6) and DBA/2 (D2). We suggest a measure we term "activity density" as a means to differentiate the behavioral effects of COC and AMPH. Activity density is defined as the activity divided by the range over which it took place. It characterizes the restriction of behavioral repertoire that does not result merely from inactivity. In both the B6 and D2 mice, AMPH increased activity density in a dose-dependent fashion by restricting the range of activity compared with COC doses producing the same level of activity. While AMPH restricted the range in both genotypes, characterizing the geographical region in which the restriction took place further differentiated the genotypes. The newly developed activity density measure thus provides a more general measure than stereotypy of the path, and can differentiate the effects of AMPH and COC both within and across genotypes.

Original languageAmerican English
Pages (from-to)239-249
Number of pages11
JournalPharmacology Biochemistry and Behavior
Issue number2
StatePublished - Feb 2005
Externally publishedYes


  • Amphetamine
  • Behavioral phenotyping
  • C57BL/6J
  • Cocaine
  • DBA/2J
  • Locomotor behavior
  • Mouse
  • SEE
  • Spatial behavior
  • Stereotypy


Dive into the research topics of 'Activity density in the open field: A measure for differentiating the effect of psychostimulants'. Together they form a unique fingerprint.

Cite this