Evidence of D2 receptor expression in the nucleus incertus of the rat

PHYSIOLOGY & BEHAVIOR

卷:151

Article

Kumar, Jigna Rajesh^1,2,3,4  Rajkumar, Ramamoorthy^1,2,3  Farooq, Usman^1,2,3  Lee, Liying Corinne^1,2,3  Tan, Francis Chee Kuan^1,2,3  Dawe, Gavin S.^1,2,3,4 

[1] Natl Univ Singapore, Yong Loo Lin Sch Med, Dept Pharmacol, Singapore 117600, Singapore

[2] Natl Univ Singapore, Inst Life Sci, Neurobiol & Ageing Programme, Singapore 117456, Singapore

[3] Singapore Inst Neurotechnol SINAPSE, Singapore 117456, Singapore

[4] Natl Univ Singapore, NUS Grad Sch Integrat Sci & Engn, Singapore 117456, Singapore

关键词: Nucleus incertus;    D-2 receptors;    Quinpirole;    Locomotion;    Dopamine;    Relaxin-3;   

DOI  :  10.1016/j.physbeh.2015.08.024

来源: Elsevier

【 摘 要 】

The nucleus incertus (NI), located in the caudal brainstem, mainly consists of GABAergic neurons with widespread projections across the brain. It is the chief source of relaxin-3 in the mammalian brain and densely expresses corticotropin-releasing factor type 1 (CRF1) receptors. Several other neurotransmitters, peptides and receptors are reportedly expressed in the NI. In the present investigation, we show the expression of dopamine type-2 (D-2) receptors in the NI by reverse transcriptase-polymerase chain reaction (RT-PCR), western blotting (WB) and immunofluorescence (IF). RT-PCR did not show expression of D-3 receptors. D-2 receptor short isoform (D-2S)-like, relaxin-3, CRF1/2 receptor and NeuN immunoreactivity were co-expressed in the cells of the NI. Behavioural effects of D-2 receptor activation by intra-NI infusion of quinpirole (a D-2/D-3 agonist) were evaluated. Hypolocomotion was observed in home cage monitoring system (LABORAS) and novel environment-induced suppression of feeding behavioural paradigms. Thus the D-2 receptors expressed in the NI are likely to play a role in locomotion. Based on its strong bidirectional connections to the median raphe and interpeduncular nuclei, the NI was predicted to play a role in modulating behavioural activity and the present results lend support to this hypothesis. This is the first evidence of expression of a catecholamine receptor, D-2-like immunoreactivity, in the NI. (C) 2015 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

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