当前位置： SCI文献检索 > JOURNAL OF NEUROPHYSIOLOGY期刊下所有文献 > Nicotine excites hypothalamic arcuate anorexigenic proopiomelanocortin neurons and orexigenic neuropeptide Y neurons: similarities and differences.

Nicotine excites hypothalamic arcuate anorexigenic proopiomelanocortin neurons and orexigenic neuropeptide Y neurons: similarities and differences.

Abstract：

:Two of the biggest health problems facing us today are addiction to nicotine and the increased prevalence of obesity. Interestingly, nicotine attenuates obesity, but the underlying mechanism is not clear. Here we address the hypothesis that if weight-reducing actions of nicotine are mediated by anorexigenic proopiomelanocortin (POMC) neurons of the hypothalamic arcuate nucleus, nicotine should excite these cells. Nicotine at concentrations similar to those found in smokers, 100-1,000 nM, excited POMC cells by mechanisms based on increased spike frequency, depolarization of membrane potential, and opening of ion channels. This was mediated by activation of both α7 and α4β2 nicotinic receptors; by itself, this nicotine-mediated excitation could explain weight loss caused by nicotine. However, in control experiments nicotine also excited the orexigenic arcuate nucleus neuropeptide Y (NPY) cells. Nicotine exerted similar actions on POMC and NPY cells, with a slightly greater depolarizing action on POMC cells. Immunocytochemistry revealed cholinergic axons terminating on both cell types. Nicotine actions were direct in both cell types, with nicotine depolarizing the membrane potentials and reducing input resistance. We found no differences in the relative desensitization to nicotine between POMC and NPY neurons. Nicotine inhibited excitatory synaptic activity recorded in NPY, but not POMC, cells. Nicotine also excited hypocretin/orexin neurons that enhance cognitive arousal, but the responses were smaller than in NPY or POMC cells. Together, these results indicate that nicotine has a number of similar actions, but also a few different actions, on POMC and NPY neurons that could contribute to the weight loss associated with smoking.

journal_name

J Neurophysiol

journal_title

Journal of neurophysiology

authors

Huang H,Xu Y,van den Pol AN

doi

10.1152/jn.00740.2010

subject

Has Abstract

pub_date

2011-09-01 00:00:00

pages

1191-202

issue

eissn

0022-3077

issn

1522-1598

pii

jn.00740.2010

journal_volume

106

pub_type

杂志文章

在线工具

Nicotine excites hypothalamic arcuate anorexigenic proopiomelanocortin neurons and orexigenic neuropeptide Y neurons: similarities and differences.