Skip to main content
. Author manuscript; available in PMC: 2013 Mar 1.
Published in final edited form as: Addict Biol. 2011 Aug 4;17(2):365–377. doi: 10.1111/j.1369-1600.2011.00358.x

Table 1.

Mean (± SEM) Reinforcement Rates and Active and Inactive Lever Presses During Self-Administration Training Prior to Examining Acute and Long-Term Effects of Enrichment

Group (n) Reinforcement rates
Lever press rates/session, last 5 sessions
Total infusions Infusions/session, last 5 sessions Active lever Inactive Lever
Cocaine
IC/Short (10) 479.5 ± 37.7 36.8 ± 1.8 211.3 ± 15.2 2.7 ± 1.6
EE/Short (9) 494.0 ± 37.1 40.7 ± 2.8 221.6 ± 19.8 5.5 ± 2.4
IC/Long (10) 489.4 ± 34.8 40.3 ± 2.2 218.0 ± 17.1 4.6 ± 3.8
EE/Long (10) 481.2 ± 40.3 37.8 ± 2.4 214.8 ± 15.7 6.5 ± 5.8
Saline-Yoked
IC/Short (10) N.A. N.A. 4.9 ± 1.8 6.2 ± 2.3
EE/Short (10) N.A. N.A. 3.6 ± 2.1 4.1 ± 1.9
IC/Long (10) N.A. N.A. 1.6 ± 0.9 5.6 ± 2.3
EE/Long (10) N.A. N.A. 2.4 ± 1.4 4.8 ± 1.7

Note. Group abbreviations refer to Isolated Condition (IC) or Environmental Enrichment (EE) for either a Short (i.e., 1 day) or Long (i.e., 21 days) period of forced abstinence.