Acute nicotine induces anxiety and disrupts temporal pattern organization of rat exploratory behavior in hole-board: a potential role for the lateral habenula

• Published in: Frontiers in cellular neuroscience Vol. 9; p. 197
• Main Authors: Casarrubea, Maurizio, Davies, Caitlin, Faulisi, Fabiana, Pierucci, Massimo, Colangeli, Roberto, Partridge, Lucy, Chambers, Stephanie, Cassar, Daniel, Valentino, Mario, Muscat, Richard, Benigno, Arcangelo, Crescimanno, Giuseppe, Di Giovanni, Giuseppe
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Research Foundation 01.06.2015; Frontiers Media S.A
• Subjects: Addictions; Addictive behaviors; Animals; Anxiety; Anxiolytics; Aversion; Behavior; Dopamine; Drug abuse; Drug addiction; Emotional behavior; Exploratory behavior; Grooming; Habenula; Lateral habenula; Luteinizing hormone; Neuroscience; Nicotine; Physiology; Rodents; Serotonin; Smoking; T-pattern analysis; Tobacco smoking; United Kingdom > UK; anxiety; T-pattern analysis; nicotine; serotonin; dopamine; lateral habenula
• ISSN: 1662-5102; 1662-5102
• DOI: 10.3389/fncel.2015.00197

Nicotine is one of the most addictive drugs of abuse. Tobacco smoking is a major cause of many health problems, and is the first preventable cause of death worldwide. Several findings show that nicotine exerts significant aversive as well as the well-known rewarding motivational effects. Less certain is the anatomical substrate that mediates or enables nicotine aversion. Here, we show that acute nicotine induces anxiogenic-like effects in rats at the doses investigated (0.1, 0.5, and 1.0 mg/kg, i.p.), as measured by the hole-board apparatus and manifested in behaviors such as decreased rearing and head-dipping and increased grooming. No changes in locomotor behavior were observed at any of the nicotine doses given. T-pattern analysis of the behavioral outcomes revealed a drastic reduction and disruption of complex behavioral patterns induced by all three nicotine doses, with the maximum effect for 1 mg/kg. Lesion of the lateral habenula (LHb) induced hyperlocomotion and, strikingly, reversed the nicotine-induced anxiety obtained at 1 mg/kg to an anxiolytic-like effect, as shown by T-pattern analysis. We suggest that the LHb is critically involved in emotional behavior states and in nicotine-induced anxiety, most likely through modulation of monoaminergic nuclei.