| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2006327 | Peptides | 2012 | 12 Pages |
We investigated the role of endogenous neuropeptide Y (NPY) system in nicotine-mediated improvement of learning and memory in rat model of Alzheimer's disease (AD). Intracerebroventricular (icv) colchicine treatment induced AD-like condition in rats and showed increased escape latency (decreased learning), and amnesic condition in probe test in Morris water maze. In these rats, nicotine (0.5 mg/kg, intraperitoneal), NPY (100 ng/rat, icv) or NPY Y1 receptor agonist [Leu31, Pro34]-NPY (0.04 ng/rat, icv) decreased escape latency by 54.76%, 55.81% and 44.18%, respectively, on day 4 of the acquisition. On the other hand, selective NPY Y1 receptor antagonist, BIBP3226 (icv) produced opposite effect (44.18%). In the probe test conducted at 24 h time point, nicotine, NPY or [Leu31, Pro34]-NPY increased the time spent by 72.72%, 44.11% and 26.47%, respectively; while BIBP3226 caused reduction (8.82%). It seems that while NPY or [Leu31, Pro34]-NPY potentiated, BIBP3226 attenuated the learning and memory enhancing effects of nicotine. Brains of colchicine treated rats showed significant reduction in NPY-immunoreactivity in the nucleus accumbens shell (cells 62.23% and fibers 50%), bed nucleus of stria terminalis (fibers 71.58%), central nucleus of amygdala (cells 74.33%), arcuate nucleus (cells 70.97% and fibers 69.65%) and dentate gyrus (cells 58.54%). However, in these rats nicotine treatment for 4 days restored NPY-immunoreactivity to the control level. We suggest that NPY, perhaps acting via NPY Y1 receptors, might interact with the endogenous cholinergic system and play a role in improving the learning and memory processes in the rats with AD-like condition.
► Nicotine and NPYergic agents improved AD-like condition in rats. ► While NPY or [Leu31, Pro34]-NPY potentiated, BIBP3226 attenuated the effect of nicotine. ► NPY-immunoreactivity was decreased in AcbSh, CeA, ARC and DG in AD-like condition. ► Nicotine treatment showed restoration of NPY-immunoreactivity in these nuclei. ► NPY, acting via NPY Y1 receptors, interacts with the endogenous cholinergic system.
