Dopamine increases in the nucleus accumbens after contingent and noncontingent ethanol administration in rats, but the contributions of the core, coreshell border, and shell subregions to this response are unclear. Also, it is not fully understood if increases in dopamine under these circumstances are due to the pharmacological effects of ethanol, stimuli associated with administration, or both. The studies presented in this dissertation were conducted to investigate dopamine’s role in each of these accumbal regions during ethanol administration and presentation of associated stimuli. Using microdialysis, ethanol and dopamine concentrations in accumbal subregions were measured every five minutes before, during, and after either experimenter-delivered intravenous ethanol or operant ethanol self-administration. After intravenous ethanol infusions, the increase in dopamine in the shell of the accumbens was significantly higher than that observed in the core. During operant ethanol self-administration, the core, core-shell border, and shell, all exhibited significant increases in dopamine during transfer of the animal into the operant chamber, with animals trained to drink sucrose + ethanol showing significantly higher increases when compared to those trained to drink sucrose alone. Dopamine increased significantly only in the core-shell border during ethanol consumption, and dopamine levels in the core and shell responded in a similar manner during all phases of the experiment. Together, these results suggest that dopamine responses to intravenous ethanol infusions and operant ethanol self-administration are subregion specific. Also, while increases in dopamine resulting from intravenous ethanol infusions in naïve animals appear to be due to the pharmacological effects of the drug, increases in ethanol-experienced animals during transfer into the operant chamber, and during ethanol consumption, may also be due to stimuli associated with ethanol administration. / text

Genetic predisposition and exposure to alcohol and stress increase the risk for alcoholism, possibly by forming a threefold interaction. This is suggested by various aspects of alcohol-induced stress response dampening in offspring of alcoholics. We tested whether such an interaction is also revealed by prolactin secretion, which is predominantly controlled by hypothalamic dopamine. Plasma prolactin was measured during four experimental days in 26 young males with a paternal history of alcoholism (PHA) and in 22 family history negative (FHN) controls. A public speaking stress paradigm was applied on the first 2 days, and a non-stress acoustic startle experiment on the others. Before the tests, subjects drank alcohol (0.6 g/kg) or placebo in a randomized, double-blind crossover design. During placebo experiments, prolactin levels significantly increased after stress, but not after startle, and did not differ between risk groups. Alcohol administration significantly increased prolactin before stress and during startle in both groups, did not alter stress-induced prolactin stimulation in FHN, but significantly attenuated the prolactin stress response in PHA subjects. The alcohol effects on prolactin, cortisol, and adrenocorticotropin stress response were positively interrelated with each other. These data confirm that alcohol specifically dampens the stress response in PHA but not FHN subjects. Since prolactin responses to stress alone and alcohol alone were normal in PHA, we conclude that this genetic effect is not related to altered physiology of the hypothalamic dopaminergic system, but to risk-group specific alcohol effects on hierarchically higher brain areas controlling the stress response in general.

Foram estudados prospectivamente 33 pacientes cujos cistos tinham volume médio de 298,4 + 346,9 (30 - 1700) ml. A punção foi realizada sob anestesia local com agulha 18 gauge, de 20 cm. Após seu esvaziamento, injetou-se etanol absoluto no volume equivalente a um terço do volume aspirado, até o máximo de 100 ml. Os volume médios observados após um, três e seis meses foram 47,9 + 59,4 (0 - 286) ml, 25,2 + 42,8 (0 - 208) ml e 12,7 + 30 (0 - 120) ml, respectivamente. Após esse período, 30 (91%) apresentaram remissão total dos sintomas, 2 (6%) mantiveram os sintomas, sendo um com cisto residual e outro sem cisto e um (3%) apresentou melhora parcial dos sintomas / A prospective series of 33 patients with symptomatic simple renal cysts varying from 30 to 1700 ml, were considered eligible for the study. The cysts were punctured under local anesthesia with an 18 gauge, 20 centimeters needle. A volume of ethanol equivalent to one third of the aspirated volume, up to a maximum of 100 ml, was injected into the cyst and left there. After one, three and six months, the average volume of the cyst was 47.9 + 59.4 (0 - 286)ml, 25.2 + 42.8 (0 - 208)ml and 12.7 + 30 (0 - 120)ml, respectively. After this period, 30 patients (91%) showed total remission of the symptoms, two patients (6%) maintained them and one patient (3%) had partial remission of the symptoms

Foram estudados prospectivamente 33 pacientes cujos cistos tinham volume médio de 298,4 + 346,9 (30 - 1700) ml. A punção foi realizada sob anestesia local com agulha 18 gauge, de 20 cm. Após seu esvaziamento, injetou-se etanol absoluto no volume equivalente a um terço do volume aspirado, até o máximo de 100 ml. Os volume médios observados após um, três e seis meses foram 47,9 + 59,4 (0 - 286) ml, 25,2 + 42,8 (0 - 208) ml e 12,7 + 30 (0 - 120) ml, respectivamente. Após esse período, 30 (91%) apresentaram remissão total dos sintomas, 2 (6%) mantiveram os sintomas, sendo um com cisto residual e outro sem cisto e um (3%) apresentou melhora parcial dos sintomas / A prospective series of 33 patients with symptomatic simple renal cysts varying from 30 to 1700 ml, were considered eligible for the study. The cysts were punctured under local anesthesia with an 18 gauge, 20 centimeters needle. A volume of ethanol equivalent to one third of the aspirated volume, up to a maximum of 100 ml, was injected into the cyst and left there. After one, three and six months, the average volume of the cyst was 47.9 + 59.4 (0 - 286)ml, 25.2 + 42.8 (0 - 208)ml and 12.7 + 30 (0 - 120)ml, respectively. After this period, 30 patients (91%) showed total remission of the symptoms, two patients (6%) maintained them and one patient (3%) had partial remission of the symptoms