Herman H. Samson

Learn More
Rats, maintained on free access to both food and water, were trained to press a lever to obtain a 20% sucrose solution. When presentation of the sucrose solution was maintaining responding, low ethanol concentrations were added to the solution. Over 25 sessions, the solution presented as reinforcement was gradually reduced in sucrose concentration until a(More)
We examined the effect of systemic administration of the endogenously occurring progesterone metabolite, allopregnanolone, on oral self-administration of ethanol by male rats. Rats were trained to perform an operant response for presentation of 0.1 ml of a solution of 10% ethanol in water using the sucrose fading technique. After acquisition of stable(More)
BACKGROUND Previous studies have demonstrated that administration of central cannabinoid receptor (CB1) ligands can produce marked effects on ingestive behaviors. However, the possible relationship to ethanol self-administration has not been fully examined. The present series of experiments was designed to characterize further the role of CB1 receptors in(More)
One of the functions of the mesolimbic dopamine (DA) system is to regulate the process of reinforcement, a process that is thought to influence drug self-administration. This study tested the effects of centrally administered DA receptor ligands on ethanol self-administration behavior. Long-Evans rats were trained to lever press on a fixed-ratio 4 schedule(More)
Rats initiated to self-administer 10% ethanol (v/v) in an operant situation using the sucrose-substitution technique received bilateral n. accumbens or caudate nucleus microinjections of d-amphetamine (4, 10, and 20 micrograms/brain), quinpirole (4 micrograms/brain), and/or raclopride (0.1, 0.5, and 1.0 micrograms/brain). Only microinjections into the n.(More)
UNLABELLED BACKGROUND This present study was designed to clarify the role of dopamine in the nucleus accumbens during operant ethanol self-administration by separating bar pressing (ethanol seeking) from ethanol consumption. Furthermore, we sought to define the relationship between ethanol in the brain and the accumbal dopamine response after oral(More)
BACKGROUND Acamprosate (calcium acetyl homotaurinate) has been used clinically to treat relapse in alcoholics. In rats, it has been shown to decrease ethanol, but not water, self-administration after ethanol deprivation. METHODS To further investigate the effect of acamprosate on reinforced behaviors in rats, the present experiment used: (1) both ethanol(More)
Rationale: The concepts of appetitive and consummatory behaviors provide a framework for examining ethanol-drinking behavior. However, traditional studies of ethanol self-administration using dipper procedures make separating the appetitive from the consummatory components difficult. Objective: This study compared the ability to initiate ethanol(More)
BACKGROUND The addition of sucrose to ethanol solutions results in a substantial increase in ethanol self-administration by rats that are deprived of neither food nor water. However, if sucrose alters ethanol absorption or metabolism, resulting in blood ethanol concentrations (BECs) not different from those resulting from lower intakes of ethanol/water(More)