The effects of continuous cocaine administration on GABA[subscript B] receptor functioning: behavioural and molecular studiesShow full item record
Title | The effects of continuous cocaine administration on GABA[subscript B] receptor functioning: behavioural and molecular studies |
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Author | Pinto, Berly Gail |
Date | 2004 |
Genre | Dissertation |
Degree | Doctor of Philosophy |
Abstract | The current experiments were aimed at understanding the association between GABA B receptors and withdrawal from continuous cocaine administration using behavioural and molecular techniques. In Experiment 1, the effects of baclofen, a GABA B receptor agonist, on basal and cocaine-induced locomotor activity were examined. Subjects were pretreated with cocaine (0, 5, 20 mg/kg/day) for 7 days and exposed to a 7-day withdrawal period. On day 7 of withdrawal, ambulation was measured in an open field for 60 min. In Experiment 1a, prior to testing, subjects were challenged with baclofen (0, 1.25, 2.5 mg/kg, i.p.). In Experiment 1b, subjects were challenged with the same doses of baclofen followed by a 15.0 mg/kg cocaine challenge 5 min later. The results indicated that cocaine administration reduced basal rearing and cocaine-induced hyperactivity. The 2.5 mg/kg baclofen challenge dose reduced basal and cocaine-induced locomotor activity in saline but not in cocaine pretreated animals. The 1.25 mg/kg baclofen dose attenuated cocaine-induced hyperactivity in saline pretreated animals. Low dose (1.25 mg/kg) baclofen abolished the effects of 5 mg/kg/day cocaine on rearing and sterotypies in response to cocaine challenge. In Experiment 2, the effects of continuous cocaine treatment on GABA B receptor protein levels were examined. Subjects were treated with continuous cocaine (0, 40 mg/kg/day) for a period of 3, 7 or 14 days and withdrawn from drug for 7 days. Following withdrawal, GABA B receptor protein levels in treated subjects were assessed by Western blot analysis. The data show that within the PFC and NACC, there were differences in GABA B receptor protein levels following 3 and 14 but not 7 days of cocaine pretreatment. Within the VTA, there were no differences in protein levels at any pretreatment period. The results of Experiments 1 & 2 suggest that the GABA B receptor system is involved in the effects of continuous cocaine and may influence actions at brain regions targeted in cocaine abuse. |
Link | https://repository.tcu.edu/handle/116099117/34874 |
Department | Psychology |
Advisor | King, George Akkaraju, Giridhar R. |
This item appears in the following Collection(s)
- Doctoral Dissertations [1510]
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