TY - JOUR
T1 - Nicotine evoked improvement in learning and memory is mediated through NPY Y1 receptors in rat model of Alzheimer's disease
AU - Rangani, Ritesh J.
AU - Upadhya, Manoj A.
AU - Nakhate, Kartik T.
AU - Kokare, Dadasaheb M.
AU - Subhedar, Nishikant K.
PY - 2012/2/1
Y1 - 2012/2/1
N2 - 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.
AB - 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.
UR - https://linkinghub.elsevier.com/retrieve/pii/S0196978112000253
U2 - 10.1016/j.peptides.2012.01.004
DO - 10.1016/j.peptides.2012.01.004
M3 - Article
SN - 0196-9781
VL - 33
SP - 317
EP - 328
JO - Peptides
JF - Peptides
IS - 2
ER -