The reinstatement of amphetamine-induced place preference is long-lasting and related to decreased expression of AMPA receptors in the nucleus accumbens

A great deal of effort has been devoted to elucidating the psychopharmacology underlying addiction and relapse. Long-term neuroadaptations in glutamate transmission seem to be of great relevance for relapse to stimulant abuse. In this study, we investigated amphetamine-induced conditioned place preference during adolescence and the reinstatement of the conditioned behavior following a priming injection of the drug 1 day (adolescence), 30 days (early adulthood) and 60 days (adulthood) after the extinction test. The nucleus accumbens was dissected immediately after the reinstatement test to examine alterations in GluR1 and NR1 subunits of glutamatergic receptors. Our results showed that a priming injection of amphetamine was able to reinstate the CPP 1 and 30 days after extinction. However, it failed to reinstate the conditioned response after 60 days. GluR1 levels were decreased on days 1 and 30 but not on day 60 while NR1 levels were unaltered in the reinstatement test. Using a relapse model we found that reinstatement of amphetamine-induced conditioning place preference during adolescence is long lasting and persists through early adulthood. Decreased levels of GluR1 in the nucleus accumbens might be related to the reinstatement of amphetamine-induced conditioning place preference. (C) 2008 IBRO. Published by Elsevier Ltd. All rights reserved.

Context-specific modulation of cocaine-induced locomotor sensitization and ERK and CREB phosphorylation in the rat nucleus accumbens

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Stress-induced reinstatement of amphetamine-conditioned place preference and changes in tyrosine hydroxylase in the nucleus accumbens in adolescent rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bed nucleus of the stria terminalis alpha(1) and alpha(2) adrenoceptors differentially modulate the cardiovascular responses to exercise in rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bed nucleus of the stria terminalis and the cardiovascular responses to chemoreflex activation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Stress induces behavioral sensitization, increases nicotine-seeking behavior and leads to a decrease of CREB in the nucleus accumbens

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characteristics of family nucleus as correlates of regular participation in sports among adolescents

Objectives To estimate the relationship between family nucleus and sport practice among adolescents.Methods A school-based cross-sectional study carried out with 1,752 Brazilian adolescents (812 male and 940 female), aged 11-17 years. Characteristics of the family nucleus (parental education, socioeconomic status and number of siblings) and sport practice (>= 240 min/week) were assessed by questionnaires. Adjusted prevalence ratios were estimated using Poisson regression models.Results The overall prevalence of sport practice was 14.8% (boys 21.2% and girls 9.4%, P = 0.001). Higher socioeconomic status, number of siblings and parents' educational level were associated with more sport practice.Conclusion Despite the low engagement, family nucleus plays an essential role in the sport practice of our sample of Brazilian adolescents.

Retinal projections and neurochemical characterization of the pregeniculate nucleus of the common marmoset (Callithrix jacchus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evidence of reciprocal connections between the dorsal raphe nucleus and the retina in the monkey Cebus apella

Possible connections between the retina and the raphe nuclei were investigated in the monkey Cebus apella by intraocular injection of cholera toxin B subunit (CTb). CTb-positive fibers were seen in the lateral region of the dorsal raphe nucleus (DR) on the side contralateral to the injection, and a few labeled perikarya were observed in the lateral portion of the DR on the ipsilateral side. Our findings suggest that direct and reciprocal connections between the retina and DR may exist in Cebus apella. These connections might be part of an important pathway through which the light/dark cycle influences the Activity and/or functional status of raphe neurons, with potential effects on a broad set of neural and behavioral circuits. (c) 2007 Elsevier B.V. All rights reserved.

5-HT1B receptor in the suprachiasmatic nucleus of the common marmoset (Callithrix jacchus)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

GABA(A) receptor activation in the lateral parabrachial nucleus induces water and hypertonic NaCl intake

Inhibitory serotonergic and cholecystokinergic mechanisms in the lateral parabrachial nucleus and central GABAergic mechanisms are involved in the regulation of water and NaCl intake. In the present study we investigated if the GABA(A) receptors in the lateral parabrachial nucleus are involved in the control of water, NaCl and food intake in rats. Male Holtzman rats with stainless steel cannulas implanted bilaterally into the lateral parabrachial nucleus were used. Bilateral injections of muscimol (0.2 nmol/0.2 mu l) into the lateral parabrachial nucleus strongly increased 0.3 M NaCl (20.3 +/- 7.2 vs. saline: 2.6 +/- 0.9 ml/180 min) without changing water intake induced by the treatment with the diuretic furosemide combined with low dose of the angiotensin converting enzyme inhibitor captopril s.c. In euhydrated and satiated rats, bilateral lateral parabrachial nucleus injections of muscimol (0.2 and 0.5 nmol/0.2 0) induced 0.3 M NaCl intake (12.1 +/- 6.5 and 32.5 +/- 7.3 ml/180 min, respectively, vs. saline: 0.4 +/- 0.2 ml/180 min) and water intake (5.2 +/- 2.0 and 7.6 +/- 2.8 ml/ 180 min, respectively, vs. saline: 0.8 +/- 0.4 ml/180 min), but no food intake (2 +/- 0.4 g/240 min vs. saline: 1 +/- 0.3 g/240 min). Bilateral lateral parabrachial nucleus injections of the GABAA antagonist bicuculline (1.6 nmol/0.2 mu l) abolished the effects of muscimol (0.5 nmol/0.2 mu l) on 0.3 M NaCl and water intake. Muscimol (0.5 nmol/0.2 mu l) into the lateral parabrachial nucleus also induced a slight ingestion of water (4.2 +/- 1.6 ml/240 min vs. saline: 1.1 +/- 0.3 ml/240 min) when only water was available, a long lasting (for at least 2 h) increase on mean arterial pressure (14 +/- 4 mm Hg, vs. saline: -1 +/- 1 mm Hg) and only a tendency to increase urinary volume and Na+ and K+ renal excretion. Therefore the activation of GABAA receptors in the lateral parabrachial nucleus induces strong NaCl intake, a small ingestion of water and pressor responses, without changes on food intake. (c) 2005 Published by Elsevier Ltd on behalf of IBRO.

GABAergic mechanisms of the lateral parabrachial nucleus on sodium appetite

GABAergic activation in the lateral parabrachial nucleus (LPBN) induces sodium and water intake in satiated and normovolemic rats. In the present study we investigated the effects of GABA(A) receptor activation in the LPBN on 0.3 M NaCl, water, 2% sucrose and food intake in rats submitted to sodium depletion (treatment with the diuretic furosemide subcutaneously + sodium deficient food for 24 h), 24 h food deprivation or 24 h water deprivation. Male Holtzman rats with bilateral stainless steel cannulas implanted into the LPBN were used. In sodium depleted rats, muscimol (GABA(A) receptor agonist, 0.5 nmol/0.2 mu/l), bilaterally injected into the LPBN, produced an inconsistent increase of water intake and two opposite effects on 0.3 M NaCl intake: an early inhibition (4.3 +/- 2.7 versus saline: 14.4 +/- 1.0 ml/15 min) and a late facilitation (37.6 +/- 2.7 versus saline: 21.1 +/- 0.9 ml/180 min). The pretreatment of the LPBN with bicuculline (GABA(A) receptor antagonist, 1.6 nmol) abolished these effects of muscimol. Muscimol into the LPBN also reduced food deprivation-induced food intake in the first 30 min of test (1.7 +/- 0.6 g versus saline: 4.1 +/- 0.6 g), without changing water deprivation-induced water intake or 2% sucrose intake in sodium depleted rats. Therefore, although GABAA receptors in the LPBN are not tonically involved in the control of sodium depletion-induced sodium intake, GABAA receptor activation in the LPBN produces an early inhibition and a late facilitation of sodium depletion-induced sodium intake. GABAA activation in the LPBN also inhibits food intake, while it consistently increases only sodium intake and not water, food or sucrose intake. (c) 2007 Elsevier B.V. All rights reserved.