Pro-cognitive and antipsychotic efficacy of the alpha7 nicotinic partial agonist SSR180711 in pharmacological and neurodevelopmental latent inhibition models of schizophrenia.

Abstract

Schizophrenia symptoms can be segregated into positive, negative and cognitive, which exhibit differential sensitivity to drug treatments. Accumulating evidence points to efficacy of alpha7 nicotinic receptor (nAChR) agonists for cognitive deficits in schizophrenia but their activity against positive symptoms is thought to be minimal. The present study examined potential pro-cognitive and antipsychotic activity of the novel selective alpha7 nAChR partial agonist SSR180711 using the latent inhibition (LI) model. LI is the reduced efficacy of a previously non-reinforced stimulus to gain behavioral control when paired with reinforcement, compared with a novel stimulus. Here, no-drug controls displayed LI if non-reinforced pre-exposure to a tone was followed by weak but not strong conditioning (2 vs 5 tone-shock pairings). MK801 (0.05 mg/kg, i.p.) -treated rats as well as rats neonatally treated with nitric oxide synthase inhibitor L-NoArg (10 mg/kg, s.c.) on postnatal days 4-5, persisted in displaying LI with strong conditioning, whereas amphetamine (1 mg/kg) -treated rats failed to show LI with weak conditioning. SSR180711 (0.3, 1, 3 mg/kg, i.p.) was able to alleviate abnormally persistent LI produced by acute MK801 and neonatal L-NoArg; these models are believed to model cognitive aspects of schizophrenia and activity here was consistent with previous findings with alpha7-nAChR agonists. In addition, unexpectedly, SSR180711 (1, 3 mg/kg, i.p.) potentiated LI with strong conditioning in no-drug controls and reversed amphetamine-induced LI disruption, two effects considered predictive of activity against positive symptoms of schizophrenia. These findings suggest that SSR180711 may be beneficial not only for the treatment of cognitive symptoms in schizophrenia, as reported multiple times previously, but also positive symptoms.

• Authors: Segev Barak, Michal Arad, Amaya De Levie, Mark D Black, Guy Griebel, Ina Weiner
• Journal: Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology (Neuropsychopharmacology) Vol. 34 Issue 7 Pg. 1753-63 (Jun 2009) ISSN: 1740-634X [Electronic] England
• PMID: 19158670 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Bridged Bicyclo Compounds, Heterocyclic
• Chrna7 protein, rat
• Enzyme Inhibitors
• Neuroprotective Agents
• Nicotinic Agonists
• Receptors, Nicotinic
• SSR180711
• alpha7 Nicotinic Acetylcholine Receptor
• Nitroarginine
• Dizocilpine Maleate

Topics

• Acoustic Stimulation (adverse effects)
• Analysis of Variance
• Animals
• Animals, Newborn
• Behavior, Animal (drug effects)
• Bridged Bicyclo Compounds, Heterocyclic (therapeutic use)
• Cognition Disorders (drug therapy, etiology)
• Conditioning, Psychological (drug effects)
• Disease Models, Animal
• Dizocilpine Maleate (therapeutic use)
• Dose-Response Relationship, Drug
• Drug Interactions
• Enzyme Inhibitors (pharmacology)
• Male
• Neural Inhibition (drug effects)
• Neuroprotective Agents (therapeutic use)
• Nicotinic Agonists (therapeutic use)
• Nitroarginine (pharmacology)
• Rats
• Rats, Wistar
• Receptors, Nicotinic
• Reinforcement, Psychology
• Schizophrenia (complications, drug therapy)
• alpha7 Nicotinic Acetylcholine Receptor