TY - JOUR
T1 - Withdrawal from morphine generalizes to a pentylenetetrazol stimulus
AU - Emmett-Oglesby, M. W.
AU - Harris, C. M.
AU - Lane, J. D.
AU - Lal, H.
PY - 1984/12
Y1 - 1984/12
N2 - Rats trained to discriminate pentylenetetrazol (PTZ) from saline in a two-lever food-reinforced operant task were given a three-day course of morphine, 15 to 45 mg/kg tid, ip. On the third day naloxone produced dose-dependent generalization to the PTZ stimulus, with 66% of subjects selecting the PTZ lever after the highest dose (0.32 mg/kg). Following termination of morphine injections, generalization of spontaneous withdrawal was tested. Approximately 50% of subjects selected the PTZ lever at 24 and 48 hrs after the last morphine, and by 96 hrs the percentage of subjects selecting the PTZ lever had dropped to 11%. Rats that chose the PTZ lever at 48 hrs were given diazepam, 5.0 mg/kg, which blocked the PTZ-like stimulus. These data demonstrate that morphine withdrawal produces a stimulus with PTZ-like characteristics which can be blocked by an anxiolytic, and they suggest that the PTZ discrimination may have general utility for investigating drug dependence and withdrawal in animals.
AB - Rats trained to discriminate pentylenetetrazol (PTZ) from saline in a two-lever food-reinforced operant task were given a three-day course of morphine, 15 to 45 mg/kg tid, ip. On the third day naloxone produced dose-dependent generalization to the PTZ stimulus, with 66% of subjects selecting the PTZ lever after the highest dose (0.32 mg/kg). Following termination of morphine injections, generalization of spontaneous withdrawal was tested. Approximately 50% of subjects selected the PTZ lever at 24 and 48 hrs after the last morphine, and by 96 hrs the percentage of subjects selecting the PTZ lever had dropped to 11%. Rats that chose the PTZ lever at 48 hrs were given diazepam, 5.0 mg/kg, which blocked the PTZ-like stimulus. These data demonstrate that morphine withdrawal produces a stimulus with PTZ-like characteristics which can be blocked by an anxiolytic, and they suggest that the PTZ discrimination may have general utility for investigating drug dependence and withdrawal in animals.
UR - http://www.scopus.com/inward/record.url?scp=0021743560&partnerID=8YFLogxK
U2 - 10.1016/0143-4179(84)90021-0
DO - 10.1016/0143-4179(84)90021-0
M3 - Article
C2 - 6543384
AN - SCOPUS:0021743560
VL - 5
SP - 37
EP - 40
JO - Neuropeptides
JF - Neuropeptides
SN - 0143-4179
IS - 1-3
ER -