Harris RBS (2020) Loss of leptin receptor-expressing cells in the hindbrain decreases forebrain leptin sensitivity. Am J Physiol Endocrinol Metab 318(5):E806-E816. doi: 10.1152/ajpendo.00020.2020
Objective: This study tested whether loss of hindbrain leptin receptor signaling changed sensitivity to forebrain leptin.
Summary: Loss of VMH (ventromedial nucleus of hippocampus) leptin receptor-expressing cells prevents weight loss. The integrated response between the hindbrain and forebrain is heavily dependent upon leptin activity in the VMH.
Usage: To test forebrain leptin sensitivity Leptin-SAP and Blank-SAP rats received third ventricle injections of 0, 0.05, 0.1, 0.25 or 0.5 μg leptin.
Qian L, Kasas L, Milne MR, Rawashdeh O, Marks N, Sharma A, Bellingham MC, Coulson EJ (2020) Cholinergic basal forebrain degeneration due to obstructive sleep apnoea increases Alzheimer’s pathology in mice. bioRxiv 2020.03.12.989848. doi: 10.1101/2020.03.12.989848
Usage: bilateral injections of urotensin II-saporin (UII-SAP; 0.07 μg/μL per site – unless stated otherwise; generous gift from Advanced Targeting Systems)
Bernabe CS, Caliman IF, Truitt WA, Molosh AI, Lowry CA, Hay-Schmidt A, Shekhar A, Johnson PL (2020) Using loss- and gain-of-function approaches to target amygdala-projecting serotonergic neurons in the dorsal raphe nucleus that enhance anxiety-related and conditioned fear behaviors. J Psychopharmacol 34(4):400-411. doi: 10.1177/0269881119900981
Objective: To investigate the role of amygdala-projecting 5-HT neurons in the DR in innate anxiety and conditioned fear behaviors.
Summary: The studies support the hypothesis that amygdala-projecting 5-HT neurons in the DR represent an anxiety and fear-on network.
Usage: Each rat received two bilateral microinjections per site (100 nL each, 1 μM in artificial cerebrospinal fluid) of either Anti-SERT-SAP or the control Mouse IgG-SAP.
Zhang F, Huan L, Xu T, Li G, Zheng B, Zhao H, Guo Y, Shi J, Sun J, Chen A (2020) Inflammatory macrophages facilitate mechanical stress-induced osteogenesis. Aging (Albany NY) 12(4):3617-3625. doi: 10.18632/aging.102833
Summary: In a mouse model of distraction osteogenesis (DO), there was significant increase in macrophages in the regeneration area. This suggests that targeting inflammatory macrophages may help to improve clinical bone repair.
Usage: For saporin-mediated depletion of macrophages, DO-surgery-treated mice received an intraventricular (iv) injection of either Mac-1-SAP or Rat IgG-SAP (20µg) once every 3 days.
Crevier-Sorbo G, Rymar, VV,Crevier-Sorbo R, Sadikot AF (2020) Thalamostriatal degeneration contributes to dystonia and cholinergic interneuron dysfuntion in a mouse model of huntington’s disease. Acta Neruopatho Commun 8(1):14. doi: 10.1186/s40478-020-0878-0 PMID: 32033588
Objective: To ablate the neurons of the Thalamostrial system (TS) to elucidate their role in the motor symptoms of Huntington’s Disease.
Summary: Huntington’s disease is an autosomal disorder characterized by involuntary movement and striatal neuronal loss. Glutaminergic input from the TS is implicated in disease progression and motor deficits. Anti-ChAT-SAP is used to ablate neurons in the Thalamostrial system to understand the role these neurons played in Huntington’s.
Usage: Mice underwent unilateral, striatal injections with either Anti-ChAT-SAP (IT-42) or Rabbit IgG-SAP (IT-35). The total volume and concentration of either saporin construct was the same (0.7 μL of 0.6 μg/μL solution).
Kelly SC, McKay EC, Beck JS, Collier TJ, Dorrance AM, Counts SE (2019) Locus coeruleus degeneration induces forebrain vascular pathology in a transgenic rat model of alzheimer’s disease. J Alzheimers Dis 70(2):371-388. doi: 10.3233/JAD-190090 PMID: 31177220
Objective: To understand the extent to which locus coeruleus projection system degeneration influences vascular pathology.
Summary: Noradrenergic locus coeruleus (LC) neuron loss is a significant feature of mild cognitive impairment and Alzheimer’s disease (AD). The authors stereotactically lesioned LC projection neurons innervating the prefrontal cortex of six-month-old Tg344–19 AD rats using DBH-SAP, or an untargeted control IgG-SAP. DBH-sap-lesioned animals performed significantly worse than IgG-sap animals on the Barnes maze task in measures of both spatial and working memory. DBH-sap-lesioned rats also displayed increased amyloid and inflammation pathology compared to IgG-sap controls. Results indicate that LC projection system degeneration is a nexus lesion that compromises both vascular and neuronal function in cognitive brain areas during the prodromal stages of AD.
Usage: Anti-DBH-SAP (IT-03) or control Mouse IgG-sap (IT-18) were administered to the PFC bilaterally ( 2.5 μg/injection).
Goodman RL, He W, Lopez JA, Bedenbaugh MN, McCosh RB, Bowdridge EC, Coolen LM, Lehman MN, Hileman SM (2019) Evidence that the LH surge in ewes involves both neurokinin B–dependent and –independent actions of kisspeptin. Endocrinology 160(12):2990-3000. doi: 10.1210/en.2019-00597
Objective: To determine if NKB is involved in the RCh of the ewe in the LH surge.
Summary: NKB signaling in the RCh increases kisspeptin levels critical for the full amplitude of the LH surge in the ewe, but kisspeptin release occurs independently of retrochiamatic area (RCh) input at the onset of the surge to initiate GnRH secretion.
Usage: Bilaterial injections in the RCh of either NK3-SAP or Blank-SAP.
Tominaga M, Kusube F, Honda K, Komiya E, Takahashi N, Naito H, Suga Y, Takamori K (2019) OP11: Role of spinal cholecystokinin receptor 2 in alloknesis models. Itch 4:1-62. doi: 10.1097/itx.0000000000000030
Objective: To determine the detailed molecular and cellular mechanisms that induce alloknesis via the spinal CCK2 receptor.
Summary: Ablation of spinal CCK receptor-expressing cells by i.t. injection of CCK-SAP attenuated CCK8S-induced alloknesis in comparison with Blank-SAP control mice.
Seamon M, Ahn W, Li AJ, Ritter S, Harris RBS (2019) Leptin receptor-expressing neurons in ventromedial nucleus of the hypothalamus contribute to weight loss caused by fourth ventricle leptin infusions. Am J Physiol Endocrinol Metab 317(4):E586-E596. doi: 10.1152/ajpendo.00205.2019
Objective: To test the importance of VMH leptin responsiveness in mediating weight loss caused by fourth ventricle leptin infusion.
Summary: Leptin did not inhibit food intake and respiratory exchange ratio in rats treated with Leptin-SAP. VMH leptin receptors do not play a significant role in maintaining energy balance in basal conditions, but limit weight gain during positive energy balance.
Usage: Bilateral VMH 75-nl injections of 260 ng/ml of Leptin-SAP or Blank-SAP.
Pan H, Fatima M, Li A, Lee H, Cai W, Horwitz L, Hor CC, Zaher N, Cin M, Slade H, Huang T, Xu XZS, Duan B (2019) Identification of a spinal circuit for mechanical and persistent spontaneous itch. Neuron 103(6):1135-1149.e6. doi: 10.1016/j.neuron.2019.06.016
Objective: To identify a spinal circuit for mechanical and persistent spontaneous itch.
Summary: Findings indicate excitatory interneurons expressing Urocortin 3::Cre (Ucn3+) in the dorsal spinal cord as a valid cellular target for future therapeutic interventions against chronic itch, without affecting normal touch.
Usage: To ablate spinal GRPR+ neurons, mice were given a single intrathecal injection of either Bombesin-SAP or Blank-SAP (400 ng in 10 mL sterile saline). To ablate spinal Npra+ neurons, mice were given a single intrathecal injection of either Nppb-SAP or Blank-SAP (5 mg in 10 mL sterile saline).
