Laboratory of Addictions Neurobiology

OBJECTIVES

The central theme of our research work is the study of the biological mechanisms involved in the phenomena of dependence on drugs of abuse and affective disorders. We are currently studying the possible participation of the endogenous GABAergic system in the addictive properties of nicotine and morphine. In our studies we address the possible physical aspects of these dependencies as well as the motivational component that leads to the abusive consumption of these substances. We use, on the one hand, a classic pharmacological strategy that consists in the use of compounds capable of blocking or activating the different receptors or intracellular signaling systems that function in the central nervous system. On the other hand, we also use genetically modified animals, in particular "knock-out" mice deficient in the GABA_B1 subunit of the GABA_B receptor. We are also evaluating the participation of endogenous GABAergic and opioidergic systems in the pathophysiology of affective disorders such as anxiety, using different behavioral models and biochemical techniques. The main interest of our study consists of the development of research lines that allow the identification of new therapeutic targets to treat addiction for public health.

Outline review

MEMBERS

GRACIELA N. BALERIO

ELIANA MICAELA CANERO

RESEARCH LINES

INVOLVEMENT OF GABA_B RECEPTORS IN THE MODULATION OF THE ADDICTIVE PROPERTIES OF NICOTINE: BEHAVIORAL, BIOCHEMICAL, MOLECULAR AND GENETIC STUDIES

In our study, we used behavioral and biochemical models in wild-type and knockout mice deficient in the subunit GABA_B1 to clarify the involvement of the endogenous GABAergic system in the addictive effects of nicotine. First, we studied the acute behavioral effects of nicotine and the ability of the GABAergic agonist to prevent or attenuate the expression of somatic signs and the aversive effects of nicotine withdrawal in wildtype mice. Finally, neurochemical alterations are determined during the nicotine withdrawal syndrome and in the prevention of baclofen in brain areas related to nicotine addiction. Secondly, we evaluated the acute behavioral effects of nicotine, the motivational consequences and the somatic manifestations of the nicotine withdrawal syndrome in knockout mice deficient in each component of the endogenous GABAergic system. We also studied the reinforcing effects of nicotine with the paradigm of spatial conditioning (CPP) and the biochemical changes induced by nicotine on the extracellular levels of dopamine in the nucleus accumbens evaluated by microdialysis in vivo. The results obtained in this project may help identify potential targets for the development of new therapeutic strategies against nicotine addiction.

NEUROPSYCHOPHARMACOLOGY OF OPIOID DEPENDENCE: STUDY OF THE POSSIBLE ROLE OF THE GABA_B RECEPTOR AS A THERAPEUTIC TARGET OF OPIOID ADDICTION IN BOTH SEXES

Taking into account the health repercussions and the high socio-economic cost of the use of drugs of abuse worldwide, it is becoming increasingly interesting to study the mechanisms of action and in particular the possible neurobiological mechanisms involved in drug abuse addictive properties of said substances. Thus, neurobiological mechanisms involved in morphine (MOR) addiction have a remarkable interest both at the level of basic research and the clinical significance of the possible results obtained. The generation of knockout mice deficient in the GABA_B1 subunit provides us with a very useful tool to clarify the specific implication of one of the components of the endogenous GABAergic system in the addiction to the different drugs of abuse. Our hypothesis is that one of the components of the endogenous GABAergic system (GABA_B receptors) can play a crucial role in the modulation of the addictive properties of MOR. This hypothesis is investigated in wild mice (pharmacological approach) and in knockout mice (genetic approach).

On the other hand, the fact that there are significant sexual differences with respect to various pharmacological properties of MOR, stands out. Taking into account that the generality of the studies carried out to date indicates that males are more sensitive to the effects of MOR, we conducted these studies in animals of both sexes in order to deepen the analysis of sexual differences related to the addictive properties of MOR. In this context, as a general objective of the research line we propose to analyze if there are sexual differences in different aspects of the addictive process of MOR, to evaluate a possible participation of one of the components of the endogenous GABAergic system (GABA_B receptors) in different aspects of the addictive process of MOR, such as the induction of physical dependence in animals of both sexes after chronic treatment and short-term abstinence in its motivational component and finally evaluate the biological mechanism underlying the preventive role of baclofen, a selective agonist of the GABA_B receptors, in different aspects of the MOR addictive process.

STUDY OF THE INVOLVEMENT OF THE CB1 RECEPTOR IN THE VULNERABILITY OF MORPHINE DEPENDENCE IN ADOLESCENT MICE EXPOSED PRENATALLY TO CANNABINOID DRUGS

Marijuana is one of the most commonly used and abused drugs of abuse by adolescents and women during pregnancy and / or breastfeeding. The increase in consumption would be due to the conception that its use is virtually free of harmful effects. However, it has been observed that children born from mothers who use marijuana are more likely to suffer cognitive deficits.

There is evidence that exposure to cannabinoids during critical periods of early prenatal or postnatal development affects the catecholaminergic, serotonergic, gabaergic, glutamatergic and opioid neurotransmission systems. Particularly, the endogenous opioid system is influenced by prenatal exposure to cannabinoids. In this context, as a general objective of the research line, we propose to evaluate whether prenatal exposure to cannabinoid agonists affects the vulnerability of dependence to opioid drugs during the adolescence.

We propose to study, in wild-type mice and knockout mice for the CB1 receptor, whether prenatal exposure with the cannabinoid agonist WIN 55212-2 alters the vulnerability of morphine dependence during the adolescence, by evaluating the intensity of somatic signs during the withdrawal syndrome to morphine. We will study the expression of neuronal and glial markers in mesolimbic areas of morphine-dependent and abstinence-dependent adolescent mice, which were prenatally exposed to cannabinoid agonists, with special emphasis on the synaptic organization and the synaptic ultrastructure in these areas.

RECENT PUBLICATIONS

- Nicotine-induced molecular alterations are modulated by GABA_Breceptor activity. Varani AP, Pedrón VT, Aon AJ, Höcht C, Acosta GB, Bettler B and Balerio GN. Addiction Biology, Vol.23(1):230-246, 2018.

- Baclofen prevents the elevated plus maze behaviour and BDNF expression during naloxone precipitated morphine withdrawal in male and female mice. Valeria T. Pedrón, Andrés P. Varani and Graciela N. Balerio. Synapse, Vol.70:187-197, 2016.

- Lack of GABAB receptors modifies behavioural and biochemical alterations induced by nicotine abstinence. Andrés P. Varani, Valeria T. Pedrón, Lirane Moutinho Machado, Marta C. Antonelli, Bernhard Bettler and Graciela N. Balerio. Neuropharmacology, Vol 90:90-101, 2015.

- Baclofen prevented the changes in c-Fos and brain-derived neutrophic factor expressions during mecamylamine-precipitated nicotine withdrawal in mice. Andrés P. Varani, Lirane Moutinho Machado and Graciela N. Balerio. Synapse, Vol.68(11):508-17, 2014.

- Baclofen and 2-OH-saclofen modify acute hypolocomotive and antinociceptive effects of nicotine administration in mice. Andrés P. Varani, Ester Aso, Rafael Maldonado, Graciela N. Balerio. European Journal of Pharmacology, Vol.738:200-5, 2014.

- Involvement of GABAB receptors in biochemical alterations induced by anxiety-related responses to nicotine in mice: Genetic and pharmacological approaches. Andrés P. Varani, Valeria T. Pedrón, Bernhard Bettler and Graciela N. Balerio. Neuropharmacology, Vol.81: 31-41, 2014.

- Attenuation by baclofen of nicotine rewarding properties and nicotine withdrawal manifestations. Andrés P. Varani, Ester Aso, Lirane Machado Moutinho, Rafael Maldonado, Graciela N. Balerio. Psychopharmacology, (Berl), Vol.231(15):3031-40, 2014.

- Mecamylamine-precipitated nicotine withdrawal syndrome and its prevention with baclofen: An autoradiographic study of α4β2 nicotinic acetylcholine receptors in mice. Varani A. P., Antonelli M. C. and Balerio G. N. Progress in Neuro-Psychopharmacology & Biological Psychiatry, Vol. 44: 217-225, 2013.

- Baclofen did not modify sexually dimorphic c-Fos expression during morphine withdrawal syndrome. Pedrón Valeria, Taravini Irene R, Induni Andrea S. and Balerio Graciela N. Synapse, Vol.67(3):118-26, 2013.

- Acute behavioural responses to nicotine and nicotine withdrawal syndrome are modified in GABAB1 knockout mice. Andrés P. Varani, Lirane Moutinho Machado, Bernhard Bettler and Graciela N. Balerio. Neuropharmacology, Vol. 63: 863-872, 2012.

- GABAB receptors involvement in the effects induced by nicotine on anxiety-related behavior in mice. Varani Andrés P. and Balerio Graciela N. Pharmacologycal Reasearch, Vol. 65: 507-513, 2012.

- Ability of baclofen to prevent somatic manifestations and neurochemical changes during nicotine withdrawal. Varani Andrés P., Moutinho Lirane, Calvo Mariela and Balerio Graciela N. Drug and Alcohol Dependence, Vol. 119: e5-e12, 2011.

- Pharmacokinetic aspects of naloxone - precipitated morphine withdrawal in male and female prepubertal mice. Silvina L. Diaz, María P. Hermida, Leonel D. Joannas, Mónica Olivera, Adriana Ridolfi, Eda C. Villaamil and Graciela N. Balerio. Biopharmaceutics & Drug Disposition, Vol 28: 283-289, 2007.

- Morphine withdrawal syndrome and its prevention with baclofen: autoradiographic study of m-opioid receptors in prepubertal male and female mice. Silvina L. Diaz, Virginia G. Barros, Marta C. Antonelli, Modesto C. Rubio and Graciela N. Balerio. Synapse, Vol 60(2):132-140, 2006.

- Role of the cannabinoid system in the effects induced by nicotine on anxiety-like behaviour in mice. Graciela N. Balerio, Ester Aso and Rafael Maldonado. Psychopharmacology, Vol 184: 504-513, 2006.

- Morphine withdrawal syndrome: involvement of the dopaminergic system in prepubertal male and female mice. Silvina L. Diaz, Alma K Kemmling, Modesto C Rubio and Graciela N. Balerio. Pharmacology, Biochemistry and Behavior.Vol 82(4): 601-607, 2005.

- Involvement of the opioid system in the effects induced by nicotine on anxiety-like behaviour in mice. Graciela N. Balerio, Ester Aso and Rafael Maldonado. Psychopharmacology, Vol 181(2):260-269, 2005.

- Baclofen reestablishes the m-opioid receptor levels modified by the morphine withdrawal syndrome in either sexes. Silvina L. Diaz, Alma K. Kemmling, Carla D. Bonavita, Modesto C. Rubio and Graciela N. Balerio. Synapse, Vol 54, pp 24-29, 2004.

- D9-tetrahydrocannabinol decreases somatic and motivational manifestations of nicotine withdrawal in mice. Graciela N. Balerio, Ester Aso, Fernando Berrendero, Patricia Murtra and Rafael Maldonado. European Journal of Neuroscience, Vol. 20, pp 2737-2748., 2004.

- Study of the behavioural responses related to the potential addictive properties of MDMA in mice. Patricia Robledo, Graciela Balerio, Fernando Berrendero and Rafael Maldonado. Naunyn Schmiedeberg’s Archives of Pharmacology, Vol. 369, pp 338-349, 2004.

- Baclofen reestablishes the dopaminergic neurons activity during naloxone-precipitated withdrawal. Silvina L. Diaz, Alma K. Kemmling and Graciela N. Balerio. Neurochemistry International, Vol. 42(4), pp 293-298, 2003.

CURRENT FINANCING SOURCES

- Member as Visiting Professor of International Subsidies

Project title: Ajut per donar suport a les activitats dels grups de recerca consolidats.

Duration: 2014-2018

Financing entity: Generalitat de Catalunya, AGAUR (2014-SGR-1547)

Principal investigator: Dr. Rafael Maldonado (UPF)

- Project Director of Scientific Programming Research 2017-2020

2017 UBA 20020160100120BA "THE GABA_B RECEPTOR AS A MODULATOR OF THE ANALGESIC EFECT AND POTENTIAL THERAPEUTIC TARGET OF OPIATES ADDITION". Director: Dr. Graciela N. Balerio

COLLABORATIONS

International

Dr. Rafael Maldonado. Neuropharmacology Laboratory. Pompeu Fabra University, Barcelona, Spain.

Dr. Bernhard Bettler, Department of Biomedicine, Institute of Physiology, Pharmazentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056 Basel, Switzerland.

National

Dra. Marta Antonelli, Independent Researcher, CONICET, of the Institute of Cellular Biology and Neurosciences (IBCN-CONICET).

Dra. Herminia Alicia Brusco. Director of the Institute of Cell Biology and Neurosciences (IBCN-CONICET).

Dra. Cristina Arranz. Full Professor Chair of Physiology and Dean of the Faculty of Pharmacy and Biochemistry, Independent Investigator of CONICET.