Environmental enrichment protects against the acquisition of cocaine self-administration in adult male rats, but does not eliminate avoidance of a drug-associated saccharin cue

Matthew D. Puhl, Joshua S. Blum, Stefany Acosta-Torres, Patricia S. Grigson

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

One of the most menacing consequences of drug addiction is the devaluation of natural rewards (e.g. food, sex, work, money, caring for one's offspring). However, evidence also suggests that natural rewards, such as an enriched environment, can devalue drugs of abuse. Thus, this study used a rodent model to test whether exposure to an enriched environment could protect adult rats from acquiring cocaine self-administration and from the resultant drug-induced devaluation of a natural saccharin reward cue. Adult male Sprague-Dawley rats were implanted with intravenous jugular catheters. Rats were then separated into two housing conditions: an enriched condition, including social companions(four/cage) and novel objects (e.g. balls, polyethylene tubes, paper, etc.), and a nonenriched condition where the rats were singly housed with no novel objects. During testing, the rats were given 5-min access to 0.15% saccharin, followed by 1 h to self-administer saline or cocaine (0.167 mg/infusion) on fixed ratio and progressive ratio schedules of reinforcement. The results showed that rats that were singly housed in the nonenriched environment fell into two groups: low drug-takers (n=34) and high drug-takers (n=12). In comparison, only one out of the 22 rats housed in the enriched environment was a high drug-taker. Thus, all rats in the enriched environment, except one, behaved like low drug-takers under the nonenriched condition. As such, these rats self-administered almost no drug on either the fixed ratio or the progressive ratio schedule of reinforcement and were extremely slow to self-administer their first cocaine infusion. Interestingly, despite their very low levels of drug self-administration, low-drug-taking rats housed in the enriched environment continued to avoid intake of the drug-associated saccharin cue. Taken together, these data suggest that the enriched environment itself served as a salient natural reward that reduced cocaine seeking and cocaine taking, but had little impact on avoidance of the cocaine-paired taste cue. The protective effects of the enriched environment were robust and, as such, have important implications for the methods used in the study of drug addiction in animal models and for the prevention, and possibly the treatment, of the disease in adult humans.

Original languageEnglish (US)
Pages (from-to)43-53
Number of pages11
JournalBehavioural Pharmacology
Volume23
Issue number1
DOIs
StatePublished - Feb 1 2012

Fingerprint

Saccharin
Self Administration
Cocaine
Cues
Pharmaceutical Preparations
Reward
Reinforcement Schedule
Substance-Related Disorders
Sex Work
Social Conditions
Street Drugs
Polyethylene
Sprague Dawley Rats
Rodentia
Neck
Catheters
Animal Models
Food

All Science Journal Classification (ASJC) codes

  • Pharmacology
  • Psychiatry and Mental health

Cite this

@article{bea9b47567e94a63970fafe18e8387e5,
title = "Environmental enrichment protects against the acquisition of cocaine self-administration in adult male rats, but does not eliminate avoidance of a drug-associated saccharin cue",
abstract = "One of the most menacing consequences of drug addiction is the devaluation of natural rewards (e.g. food, sex, work, money, caring for one's offspring). However, evidence also suggests that natural rewards, such as an enriched environment, can devalue drugs of abuse. Thus, this study used a rodent model to test whether exposure to an enriched environment could protect adult rats from acquiring cocaine self-administration and from the resultant drug-induced devaluation of a natural saccharin reward cue. Adult male Sprague-Dawley rats were implanted with intravenous jugular catheters. Rats were then separated into two housing conditions: an enriched condition, including social companions(four/cage) and novel objects (e.g. balls, polyethylene tubes, paper, etc.), and a nonenriched condition where the rats were singly housed with no novel objects. During testing, the rats were given 5-min access to 0.15{\%} saccharin, followed by 1 h to self-administer saline or cocaine (0.167 mg/infusion) on fixed ratio and progressive ratio schedules of reinforcement. The results showed that rats that were singly housed in the nonenriched environment fell into two groups: low drug-takers (n=34) and high drug-takers (n=12). In comparison, only one out of the 22 rats housed in the enriched environment was a high drug-taker. Thus, all rats in the enriched environment, except one, behaved like low drug-takers under the nonenriched condition. As such, these rats self-administered almost no drug on either the fixed ratio or the progressive ratio schedule of reinforcement and were extremely slow to self-administer their first cocaine infusion. Interestingly, despite their very low levels of drug self-administration, low-drug-taking rats housed in the enriched environment continued to avoid intake of the drug-associated saccharin cue. Taken together, these data suggest that the enriched environment itself served as a salient natural reward that reduced cocaine seeking and cocaine taking, but had little impact on avoidance of the cocaine-paired taste cue. The protective effects of the enriched environment were robust and, as such, have important implications for the methods used in the study of drug addiction in animal models and for the prevention, and possibly the treatment, of the disease in adult humans.",
author = "Puhl, {Matthew D.} and Blum, {Joshua S.} and Stefany Acosta-Torres and Grigson, {Patricia S.}",
year = "2012",
month = "2",
day = "1",
doi = "10.1097/FBP.0b013e32834eb060",
language = "English (US)",
volume = "23",
pages = "43--53",
journal = "Behavioural Pharmacology",
issn = "0955-8810",
publisher = "Lippincott Williams and Wilkins",
number = "1",

}

Environmental enrichment protects against the acquisition of cocaine self-administration in adult male rats, but does not eliminate avoidance of a drug-associated saccharin cue. / Puhl, Matthew D.; Blum, Joshua S.; Acosta-Torres, Stefany; Grigson, Patricia S.

In: Behavioural Pharmacology, Vol. 23, No. 1, 01.02.2012, p. 43-53.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Environmental enrichment protects against the acquisition of cocaine self-administration in adult male rats, but does not eliminate avoidance of a drug-associated saccharin cue

AU - Puhl, Matthew D.

AU - Blum, Joshua S.

AU - Acosta-Torres, Stefany

AU - Grigson, Patricia S.

PY - 2012/2/1

Y1 - 2012/2/1

N2 - One of the most menacing consequences of drug addiction is the devaluation of natural rewards (e.g. food, sex, work, money, caring for one's offspring). However, evidence also suggests that natural rewards, such as an enriched environment, can devalue drugs of abuse. Thus, this study used a rodent model to test whether exposure to an enriched environment could protect adult rats from acquiring cocaine self-administration and from the resultant drug-induced devaluation of a natural saccharin reward cue. Adult male Sprague-Dawley rats were implanted with intravenous jugular catheters. Rats were then separated into two housing conditions: an enriched condition, including social companions(four/cage) and novel objects (e.g. balls, polyethylene tubes, paper, etc.), and a nonenriched condition where the rats were singly housed with no novel objects. During testing, the rats were given 5-min access to 0.15% saccharin, followed by 1 h to self-administer saline or cocaine (0.167 mg/infusion) on fixed ratio and progressive ratio schedules of reinforcement. The results showed that rats that were singly housed in the nonenriched environment fell into two groups: low drug-takers (n=34) and high drug-takers (n=12). In comparison, only one out of the 22 rats housed in the enriched environment was a high drug-taker. Thus, all rats in the enriched environment, except one, behaved like low drug-takers under the nonenriched condition. As such, these rats self-administered almost no drug on either the fixed ratio or the progressive ratio schedule of reinforcement and were extremely slow to self-administer their first cocaine infusion. Interestingly, despite their very low levels of drug self-administration, low-drug-taking rats housed in the enriched environment continued to avoid intake of the drug-associated saccharin cue. Taken together, these data suggest that the enriched environment itself served as a salient natural reward that reduced cocaine seeking and cocaine taking, but had little impact on avoidance of the cocaine-paired taste cue. The protective effects of the enriched environment were robust and, as such, have important implications for the methods used in the study of drug addiction in animal models and for the prevention, and possibly the treatment, of the disease in adult humans.

AB - One of the most menacing consequences of drug addiction is the devaluation of natural rewards (e.g. food, sex, work, money, caring for one's offspring). However, evidence also suggests that natural rewards, such as an enriched environment, can devalue drugs of abuse. Thus, this study used a rodent model to test whether exposure to an enriched environment could protect adult rats from acquiring cocaine self-administration and from the resultant drug-induced devaluation of a natural saccharin reward cue. Adult male Sprague-Dawley rats were implanted with intravenous jugular catheters. Rats were then separated into two housing conditions: an enriched condition, including social companions(four/cage) and novel objects (e.g. balls, polyethylene tubes, paper, etc.), and a nonenriched condition where the rats were singly housed with no novel objects. During testing, the rats were given 5-min access to 0.15% saccharin, followed by 1 h to self-administer saline or cocaine (0.167 mg/infusion) on fixed ratio and progressive ratio schedules of reinforcement. The results showed that rats that were singly housed in the nonenriched environment fell into two groups: low drug-takers (n=34) and high drug-takers (n=12). In comparison, only one out of the 22 rats housed in the enriched environment was a high drug-taker. Thus, all rats in the enriched environment, except one, behaved like low drug-takers under the nonenriched condition. As such, these rats self-administered almost no drug on either the fixed ratio or the progressive ratio schedule of reinforcement and were extremely slow to self-administer their first cocaine infusion. Interestingly, despite their very low levels of drug self-administration, low-drug-taking rats housed in the enriched environment continued to avoid intake of the drug-associated saccharin cue. Taken together, these data suggest that the enriched environment itself served as a salient natural reward that reduced cocaine seeking and cocaine taking, but had little impact on avoidance of the cocaine-paired taste cue. The protective effects of the enriched environment were robust and, as such, have important implications for the methods used in the study of drug addiction in animal models and for the prevention, and possibly the treatment, of the disease in adult humans.

UR - http://www.scopus.com/inward/record.url?scp=84855666714&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84855666714&partnerID=8YFLogxK

U2 - 10.1097/FBP.0b013e32834eb060

DO - 10.1097/FBP.0b013e32834eb060

M3 - Article

C2 - 22157144

AN - SCOPUS:84855666714

VL - 23

SP - 43

EP - 53

JO - Behavioural Pharmacology

JF - Behavioural Pharmacology

SN - 0955-8810

IS - 1

ER -