Enkephalin levels and the number of neuropeptide Y-containing interneurons in the hippocampus are decreased in female cannabinoid-receptor 1 knock-out mice

NEUROSCIENCE LETTERS

卷:620

Article

Rogers, Sophie A.¹  Van Kempen, Tracey A.^1,2  Pickel, Virginia M.^1,2  Milner, Teresa A.^1,2,3 

[1] Weill Cornell Med, Feil Family Brain & Mind Res Inst, 407 East 61st St, New York, NY 10065 USA

[2] Weill Cornell Med, Weill Cornell Grad Sch Med Sci, 1300 York Ave, New York, NY 10021 USA

[3] Rockefeller Univ, Harold & Margaret Milliken Hatch Lab Endocrinol, 1230 York Ave, New York, NY 10065 USA

关键词: Opioid;    Cannabinoid;    Female mice;    Neuropeptide Y;    Parvalbumin;    Hippocampus;   

DOI  :  10.1016/j.neulet.2016.03.030

来源: Elsevier

【 摘 要 】

Drug addiction requires learning and memory processes that are facilitated by activation of cannabinoid-1 (CB1) and opioid receptors in the hippocampus. This involves activity-dependent synaptic plasticity that is partially regulated by endogenous opioid (enkephalin and dynorphin) and non-opioid peptides, specifically cholecystokinin, parvalbumin and neuropeptide Y, the neuropeptides present in inhibitory interneurons that co-express CB1 or selective opioid receptors. We tested the hypothesis that CB1 receptor expression is a determinant of the availability of one or more of these peptide modulators in the hippocampus. This was achieved by quantitatively analyzing the immunoperoxidase labeling for each of these neuropeptide in the dorsal hippocampus of female wild-type (CB1+/+) and cannabinoid receptor 1 knockout (CB1-/-) C57/BL6 mice. The levels of Leu(5)-enkephalin-immunoreactivity were significantly reduced in the hilus of the dentate gyrus and in stratum lucidum of CA3 in CB1-/- mice. Moreover, the numbers of neuropeptide Y-immunoreactive interneurons in the dentate hilus were significantly lower in the CB1-/- compared to wild-type mice. However, CB1+/+ and CB1-/- mice did not significantly differ in expression levels of either dynorphin or cholecystokinin, and showed no differences in numbers of parvalbumin-containing interneurons. These findings suggest that the cannabinoid and opioid systems have a nuanced, regulatory relationship that could affect the balance of excitation and inhibition in the hippocampus and thus processes such as learning that rely on this balance. (C) 2016 Elsevier Ireland Ltd. All rights reserved.

【 授权许可】

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