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Imaging CA1-hippocampal neuronal ensembles during nicotine-dependent contextual associations
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Poster abstracts / Biochemical Pharmacology 97 (2015) 621–636
Fund, Barrow Neurological Foundation. Additional scientific contributions by Yan Gan, Junwei Hao and Ning Su. http://dx.doi.org/10.1016/j.bcp.2015.08.036
2.13 The role of the dynorphin-kappa-opioid system in reinstatement of nicotine-seeking in mouse self-administration A.M. Gomez 1, M.R. Bruchas 1,2
2.12 Imaging CA1-hippocampal neuronal ensembles during nicotine-dependent contextual associations Li Xia 1,*, Stephanie Nygard 2,*, Ben Acland 3, Nicholas Hourguettes 2, Gabe Sobczak 1, Michael Bruchas 1,2,3,4 1
Biomedical Engineering, Washington University, St. Louis, MO, USA 2 Anesthesiology, Washington University, St. Louis, MO, USA 3 Neuroscience Program (DBBS), Washington University, St. Louis, MO, USA 4 Washington University Pain Center, Washington University, St. Louis, MO, USA *Corresponding authors. Learned associations between environmental cues and the rewarding properties of addictive drugs are a major cause for relapse among drug addicts. The hippocampus (HIP) is therefore a likely key player in the development of addictive behaviors. The link between learning and memory systems, contextual cues, and reward circuitry is largely unknown. The conditioned place preference (CPP) paradigm attempts to model this aspect of drug reward-associations and can be useful in examining the underlying neural circuitry involved in the formation of drug-associated memories. Here we combine in vivo calcium imaging of CaMKIIa CA1 HIP neurons with CPP to study the role of the HIP in nicotineinduced behaviors. We injected AAV5-CaMKIIa-GcAMP6f-eYFP into the HIP CA1 area and, implanted a 1 mm diameter and 4 mm length GRIN lens is 100 mm above the injected region. After another 1–2 weeks, we use a microscope camera from INSCOPIX to observe this the neuron activity in the CA1 area can be observed from the microscope. We then used a standard unbiased, counterbalanced CPP protocol to observe neuronal activity during the development of nicotine CPP. Mice were pre-tested in the CPP boxes on day 1, and days 2–3, they received saline in the AM and nicotine (0.5 mg/kg, s.c.) in the PM for a 20 min session. On day 5, they were tested for nicotine place preference, as determined by the time they spent in the drug-paired chamber post-test minus pre-test. After collecting all data from each session, MosaicTM is used to preprocess the data by reducing dataset, meaning filer, motion correction. By PCA/ICA, single neuron activity was separated and sorted manually. Each session retrieved one dataset for single neuron spatial filters and one dataset set for their time course. After comparing neuron activity between two CPP chambers within posttest section, we found distinct patterns of neuronal activity when a mouse enters the nicotine-paired chamber compared to the saline-paired chamber potentially indicating that cue-reward neuronal activity is potentiated during conditioning and formation of preference. Follow-up studies were conducted in which AAV5-CaMKIIa-HA-hM4D(Gi)IRES-mCitrine was injected into the CA1 HIP region to show that silencing CA1, CAMKII+ cell activity in this is sufficient to block the development of nicotine-induced CPP. Taken together, our data provide unique evidence for a key role of the CA1 HIP region in nicotine-contextual associations and begin to dissect the circuitry mediating the development of drug-reward cue associations. Acknowledgements: Supported by R01DA033396 (M.R.B), and T32DA007261-22 (S.K.N.) from NIDA, DECODE, Inscopix. http://dx.doi.org/10.1016/j.bcp.2015.08.037
1 Departments of Anesthesiology Division of Basic Research, Anatomy and Neurobiology, and Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA 2 Division of Biological and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO, USA
Nicotine is the most widely used addictive substance, and its use is accompanied by a high propensity for relapse. However, the neurobiological mechanisms underlying nicotine relapse/reinstatement remain unclear. Prior studies have shown that in rodents, activation of the kappa-opioid receptor (KOR) system via stress-induced dynorphin release elicits negative affective states, and thereby triggering reinstatement of drug-seeking behaviors. Therefore, our goal is to establish the role of the dynorphin/KOR system in stress-induced reinstatement of nicotine-seeking. We first trained male C57BL/6 mice to self-administer nicotine intravenously (0.03 mg/kg/infusion, 60 min sessions) on a fixed ratio-5 schedule of reinforcement for a minimum of 14 days. After stable levels of nicotine intake were established, mice underwent extinction training until criterion was reached (20% of responding compared to last nicotine self-administration session). We then investigated whether activation of KORs were sufficient to induce reinstatement of nicotine-seeking. Indeed, mice showed a robust reinstatement response after administration of the KOR agonist, U50,488 (2.5–5.0 mg/kg, i.p., 30 min prior to reinstatement test). This data suggests that activation of the KOR system is sufficient to cause nicotine-seeking in mice. Currently, we are exploring whether KORs are necessary for stress-induced reinstatement of nicotine-seeking via administration of systemic KOR selective antagonists. Future follow-up studies will focus on dissecting the specific neural circuitry underlying KOR-mediated reinstatement of nicotine-seeking. Acknowledgements: Supported by R01DA033396 (M.R.B), and 3R01DA033396-02S1 (A.M.G, M.R.B.) from NIDA. Disclosure: The authors have no conflicts of interest to disclose. http://dx.doi.org/10.1016/j.bcp.2015.08.038 2.14 a5 nAChR modulation of the effects of nicotine on ventral-striatal DA release and cue-reward learning W. Howe, P.L. Tierney, A. Rossi, D. Young, E. Guillmette, R. Kozak Pfizer, Inc., Neuroscience Research Unit, Cambridge, MA, USA Previous work has shown that the a5 nicotinic acetylcholine receptors (nAChR) in the habenula-interpeduncular nucleus (IPN) pathway are potent modulators of nicotine consumption. Emerging data suggests that the role of a5 control of drug seeking extends beyond nicotine intake, but also to other drugs of abuse (e.g. alcohol, [1,2]), a result that might be via this receptor’s actions in circuits beyond the habenula and IPN. A substantial body of evidence shows that reward and drug seeking is controlled by mesolimbic circuitry and the modulation of dopamine (DA) release. Importantly, a5 is found throughout the mesolimbic system, including presynaptically on DA terminals in the ventral
Poster abstracts / Biochemical Pharmacology 97 (2015) 621–636
Fund, Barrow Neurological Foundation. Additional scientific contributions by Yan Gan, Junwei Hao and Ning Su. http://dx.doi.org/10.1016/j.bcp.2015.08.036
2.13 The role of the dynorphin-kappa-opioid system in reinstatement of nicotine-seeking in mouse self-administration A.M. Gomez 1, M.R. Bruchas 1,2
2.12 Imaging CA1-hippocampal neuronal ensembles during nicotine-dependent contextual associations Li Xia 1,*, Stephanie Nygard 2,*, Ben Acland 3, Nicholas Hourguettes 2, Gabe Sobczak 1, Michael Bruchas 1,2,3,4 1
Biomedical Engineering, Washington University, St. Louis, MO, USA 2 Anesthesiology, Washington University, St. Louis, MO, USA 3 Neuroscience Program (DBBS), Washington University, St. Louis, MO, USA 4 Washington University Pain Center, Washington University, St. Louis, MO, USA *Corresponding authors. Learned associations between environmental cues and the rewarding properties of addictive drugs are a major cause for relapse among drug addicts. The hippocampus (HIP) is therefore a likely key player in the development of addictive behaviors. The link between learning and memory systems, contextual cues, and reward circuitry is largely unknown. The conditioned place preference (CPP) paradigm attempts to model this aspect of drug reward-associations and can be useful in examining the underlying neural circuitry involved in the formation of drug-associated memories. Here we combine in vivo calcium imaging of CaMKIIa CA1 HIP neurons with CPP to study the role of the HIP in nicotineinduced behaviors. We injected AAV5-CaMKIIa-GcAMP6f-eYFP into the HIP CA1 area and, implanted a 1 mm diameter and 4 mm length GRIN lens is 100 mm above the injected region. After another 1–2 weeks, we use a microscope camera from INSCOPIX to observe this the neuron activity in the CA1 area can be observed from the microscope. We then used a standard unbiased, counterbalanced CPP protocol to observe neuronal activity during the development of nicotine CPP. Mice were pre-tested in the CPP boxes on day 1, and days 2–3, they received saline in the AM and nicotine (0.5 mg/kg, s.c.) in the PM for a 20 min session. On day 5, they were tested for nicotine place preference, as determined by the time they spent in the drug-paired chamber post-test minus pre-test. After collecting all data from each session, MosaicTM is used to preprocess the data by reducing dataset, meaning filer, motion correction. By PCA/ICA, single neuron activity was separated and sorted manually. Each session retrieved one dataset for single neuron spatial filters and one dataset set for their time course. After comparing neuron activity between two CPP chambers within posttest section, we found distinct patterns of neuronal activity when a mouse enters the nicotine-paired chamber compared to the saline-paired chamber potentially indicating that cue-reward neuronal activity is potentiated during conditioning and formation of preference. Follow-up studies were conducted in which AAV5-CaMKIIa-HA-hM4D(Gi)IRES-mCitrine was injected into the CA1 HIP region to show that silencing CA1, CAMKII+ cell activity in this is sufficient to block the development of nicotine-induced CPP. Taken together, our data provide unique evidence for a key role of the CA1 HIP region in nicotine-contextual associations and begin to dissect the circuitry mediating the development of drug-reward cue associations. Acknowledgements: Supported by R01DA033396 (M.R.B), and T32DA007261-22 (S.K.N.) from NIDA, DECODE, Inscopix. http://dx.doi.org/10.1016/j.bcp.2015.08.037
1 Departments of Anesthesiology Division of Basic Research, Anatomy and Neurobiology, and Washington University Pain Center, Washington University School of Medicine, St. Louis, MO, USA 2 Division of Biological and Biomedical Sciences, Washington University School of Medicine, St. Louis, MO, USA
Nicotine is the most widely used addictive substance, and its use is accompanied by a high propensity for relapse. However, the neurobiological mechanisms underlying nicotine relapse/reinstatement remain unclear. Prior studies have shown that in rodents, activation of the kappa-opioid receptor (KOR) system via stress-induced dynorphin release elicits negative affective states, and thereby triggering reinstatement of drug-seeking behaviors. Therefore, our goal is to establish the role of the dynorphin/KOR system in stress-induced reinstatement of nicotine-seeking. We first trained male C57BL/6 mice to self-administer nicotine intravenously (0.03 mg/kg/infusion, 60 min sessions) on a fixed ratio-5 schedule of reinforcement for a minimum of 14 days. After stable levels of nicotine intake were established, mice underwent extinction training until criterion was reached (20% of responding compared to last nicotine self-administration session). We then investigated whether activation of KORs were sufficient to induce reinstatement of nicotine-seeking. Indeed, mice showed a robust reinstatement response after administration of the KOR agonist, U50,488 (2.5–5.0 mg/kg, i.p., 30 min prior to reinstatement test). This data suggests that activation of the KOR system is sufficient to cause nicotine-seeking in mice. Currently, we are exploring whether KORs are necessary for stress-induced reinstatement of nicotine-seeking via administration of systemic KOR selective antagonists. Future follow-up studies will focus on dissecting the specific neural circuitry underlying KOR-mediated reinstatement of nicotine-seeking. Acknowledgements: Supported by R01DA033396 (M.R.B), and 3R01DA033396-02S1 (A.M.G, M.R.B.) from NIDA. Disclosure: The authors have no conflicts of interest to disclose. http://dx.doi.org/10.1016/j.bcp.2015.08.038 2.14 a5 nAChR modulation of the effects of nicotine on ventral-striatal DA release and cue-reward learning W. Howe, P.L. Tierney, A. Rossi, D. Young, E. Guillmette, R. Kozak Pfizer, Inc., Neuroscience Research Unit, Cambridge, MA, USA Previous work has shown that the a5 nicotinic acetylcholine receptors (nAChR) in the habenula-interpeduncular nucleus (IPN) pathway are potent modulators of nicotine consumption. Emerging data suggests that the role of a5 control of drug seeking extends beyond nicotine intake, but also to other drugs of abuse (e.g. alcohol, [1,2]), a result that might be via this receptor’s actions in circuits beyond the habenula and IPN. A substantial body of evidence shows that reward and drug seeking is controlled by mesolimbic circuitry and the modulation of dopamine (DA) release. Importantly, a5 is found throughout the mesolimbic system, including presynaptically on DA terminals in the ventral