JOURNAL ARTICLE

[Antidepressant effect of microinjection of neuropeptide Y into the hippocampus is mediated by decreased expression of nitric oxide synthase]

Ting Lian, Shu-Cheng An
Sheng Li Xue Bao: [Acta Physiologica Sinica] 2010 June 25, 62 (3): 237-46
20571741
Accumulating evidence indicates an important role of hippocampal dendrite atrophy in the development of depression, while neuropeptide Y (NPY) participates in hippocampal dendrite growth. The present study was aimed to investigate the relationship between NPY and nitric oxide synthase (NOS) in chronic unpredictable mild stress (CUMS)-induced depression. CUMS-induced depression model was established in Sprague-Dawley rats. Intrahippocampal microinjections of NPY, NPY-Y1 receptor antagonist GR231118 and non-specific NOS inhibitor N-nitro-L-arginine methyl ester (L-NAME) were respectively adopted by rat brain stereotaxic coordinates. The behavioral observations were conducted by sucrose consumption test, open field test and forced swimming test. The expressions of NPY, neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS) in hippocampus were detected by immunohistochemistry. The results showed that, compared with the control group, rats receiving CUMS for 21 d or intrahippocampal microinjection of GR231118 showed a significant reduction in body weight and depression-like behavior, which included reductions in sucrose preference, locomotor activity, rearing and grooming in open field test, and increased duration of immobility in forced swimming test. Moreover, the expression of NPY significantly decreased (P<0.01), while the expressions of nNOS and iNOS increased obviously in the hippocampal dentate gyrus (DG) and CA3 regions (P<0.01). Intrahippocampal microinjections of NPY prevented the depression-like behavioral changes induced by CUMS and decreased the expressions of nNOS and iNOS in the hippocampal DG and CA3 regions (P<0.01). Intrahippocampal microinjections of GR231118 reduced behavioral ability of the rats dramatically and significantly increased the expressions of hippocampal nNOS and iNOS (P<0.01). Intrahippocampal microinjections of L-NAME suppressed the depression-like behavioral changes induced by CUMS or intrahippocampal microinjection of GR231118. In conclusion, reduced expression of NPY and increased expression of NOS in hippocampus may make significant contributions to CUMS-induced depression. These results suggest that the antidepressant function of NPY associates with down-regulation of NOS expression in hippocampus, possibly mediated via NPY-Y1 receptor.

Full Text Links

Find Full Text Links for this Article

Discussion

You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read
20571741
×

Save your favorite articles in one place with a free QxMD account.

×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"