pnu-120596 and Cognition-Disorders

Neuroinflammation is often associated with the development of major depressive disorder (MDD)-related symptoms. Previous studies have indicated that activation of glial cells, upregulation of proinflammatory cytokines and dysregulation of adrenergic system in the central nervous system (CNS) could be the key mediators to modulate depression-related behaviors after peripheral immune activation. Central α7 nicotinic acetylcholine receptor (α7 nAChR) has a role in the regulation of the cholinergic anti-inflammatory pathway. The present study determined the effects of PNU120596, α7 nAChR positive allosteric modulator (PAM), on lipopolysaccharide (LPS)-induced anxiety, cognitive deficit, and depression-like behaviors in mice. These behaviors were evaluated 24 h after LPS (1 mg/kg) administration using elevated plus-maze, Y-maze, and forced swim test, respectively. The effects of PNU120596 on mRNA of neuroinflammatory markers and norepinephrine (NE) level in behaviorally-relevant brain regions such as the hippocampus and prefrontal cortex were examined. PNU120596 administration (1 or 4 mg/kg) showed anxiolytic, pro-cognitive, and antidepressant-like effects by preventing LPS-induced behavioral abnormalities. Following LPS treatment, PNU120596 hindered activation markers of the microglia and astrocytes (cluster of differentiation molecule 11b and glial fibrillary acidic protein) and upregulation of proinflammatory cytokines such as interleukin 1 beta and tumor necrosis factor-alpha in the hippocampus and prefrontal cortex. NE level that was reduced by peripheral LPS challenge was normalized by PNU120596 effects in both brain regions. Overall, the results in this study indicate that activation of α7 nAChR by PAM effectively prevents LPS-induced anxiety, cognitive deficit, and depression-like behaviors and regulates relevant neuroinflammatory markers in the hippocampus and prefrontal cortex.

Topics: alpha7 Nicotinic Acetylcholine Receptor; Animals; Antidepressive Agents; Anxiety; Anxiety Disorders; Astrocytes; Cognition; Cognition Disorders; Cognitive Dysfunction; Cytokines; Depression; Depressive Disorder, Major; Disease Models, Animal; Hippocampus; Inflammation; Isoxazoles; Lipopolysaccharides; Male; Mice; Mice, Inbred C57BL; Microglia; Phenylurea Compounds; Prefrontal Cortex

The α7 nicotinic acetylcholine receptors (nAChRs) have been highlighted as a target for cognitive enhancement in schizophrenia. Adult female hooded Lister rats received sub-chronic phencyclidine (PCP) (2 mg/kg) or vehicle i.p. twice daily for 7 days, followed by 7 days' washout. PCP-treated rats then received PNU-120596 (10 mg/kg; s.c.) or saline and were tested in the attentional set-shifting task. Sub-chronic PCP produced a significant cognitive deficit in the extra-dimensional shift (EDS) phase of the task (p < 0.001, compared with vehicle). PNU-120596 significantly improved performance of PCP-treated rats in the EDS phase of the attentional set-shifting task (p < 0.001). In conclusion, these data demonstrate that PNU-120596 improves cognitive dysfunction in our animal model of cognitive dysfunction in schizophrenia, most likely via modulation of α7 nACh receptors.

Topics: Allosteric Regulation; alpha7 Nicotinic Acetylcholine Receptor; Animals; Attention; Behavior, Animal; Brain; Cognition Disorders; Discrimination Learning; Disease Models, Animal; Drug Interactions; Female; Half-Life; Hallucinogens; Isoxazoles; Neurons; Neuroprotective Agents; Neurotoxicity Syndromes; Nicotinic Agonists; Phencyclidine; Phenylurea Compounds; Rats; Rats, Inbred Strains; Receptors, Nicotinic; Tissue Distribution