Dai M, Nakamura S, Takahashi C, Sato M, Munetomo A, Magata F, Uenoyama Y, Tsukamura H, Matsuda F (2021) Reduction of arcuate kappa-opioid receptor-expressing cells increased luteinizing hormone pulse frequency in female rats. Endocr J 68(8):933-941. doi: 10.1507/endocrj.EJ20-0832

Summary: The number of Kiss1-expressing cells in the ARC was not affected by ARC Dyno-SAP treatment. Dynorphin-Kappa opioid receptor (KOR) signaling within the ARC seems to mediate the suppression of the frequency of pulsatile GnRH/LH release, and neurons in the hypothalamic arcuate nucleus (ARC) non-KNDy KOR neurons may be involved in the mechanism modulating GnRH/LH pulse generation.

Usage: Female rats were stereotaxically injected with Dyno-SAP (20 ng/200 nL) or unconjugated Saporin (18.6 ng/200 nL) as a control, bilaterally into the anterior and posterior ARC (total of 4 injection sites).

Related Products: Dyno-SAP (Dynorphin-SAP) (Cat. #IT-68), Saporin (Cat. #PR-01)

Talk AC, Bernasconi D, Stevens Z, Grasby K, Edelstein L, Smythies J, Russell B (2013) The anterior claustrum and flexible behavior in the rat: A comparison of NMDA and dynorphin-saporin lesions. Neuroscience 2013 Abstracts 574.20. Society for Neuroscience, San Diego, CA.

Summary: The claustrum is a small structure of poorly understood function situated subcortically in the basal forebrain. The fact that it is extensively and reciprocally connected with the cerebral cortex has led to suggestions that it is involved in coordination of cortical activity. Here we created lesions to the anterior claustrum of rats and tested performance on tasks that involve neural processing in one or more frontal or limbic cortical structures. The excitotoxin NMDA was used to create partial lesions to the anterior claustrum. Lesions were constrained to the claustrum except in a minority of subjects. Taking into account the fact that some of the highest densities of kappa-opioid receptors in the mammalian brain are in the claustrum, in a separate study we used a custom dynorphin-saporin conjugate supplied by Advanced Targeting Systems to create lesions. We found that the claustral lesions using the targeted immunotoxin could be more complete than those provided by NMDA. In our first study, after excitotoxic lesions created by infusions of NMDA, we tested spatial reversal learning in a water maze. Lesioned rats were not impaired at acquiring the initial location of a goal platform in the maze, but were impaired at acquiring a switched location in the reversal phase. The lesioned rats also exhibited more perseverance errors compared to control rats during reversal. These same rats were not impaired at latent inhibition or working memory tasks, suggesting the effect of anterior claustral lesions may be related to behavioral flexibility. This finding is consistent with theories of claustral function that suggest it may help coordinate information necessary for cortical-dependent tasks. We are currently assessing the role of the anterior claustrum on other measures of behavioral flexibility using a cohort of rats that have been subjected to immunotoxic lesions.

Related Products: Dyno-SAP (Dynorphin-SAP) (Cat. #IT-68)