Stimulation of the muscarinic receptor M4 activates quiescent neural precursor cells and ameliorates medial septum cholinergic lesion-induced impairments in adult hippocampal neurogenesis
Madrid LI, Bandhavkar S, Hafey K, Jimenez-Martin J, Milne M, Coulson EJ, Jhaveri DJ (2022) Stimulation of the muscarinic receptor M4 activates quiescent neural precursor cells and ameliorates medial septum cholinergic lesion-induced impairments in adult hippocampal neurogenesis. bioRxiv 2022.08.25.505357. doi: 10.1101/2022.08.25.505357
Objective: To investigate the contribution of basal forebrain medial septum (MS) and diagonal band of Broca (DBB) cholinergic neurons that innervate the hippocampus and the identity of the cholinergic receptor(s) that regulate the production and maturation of new neurons.
Summary: This work reveals stage-specific roles of cholinergic signaling in regulating functionally relevant adult hippocampal neurogenesis.
Usage: Medial septum cholinergic lesion was achieved by infusion of mu p75-SAP (0.4 µg/µl). Rabbit IgG-SAP (0.4 µg/µl) was used as control.
Neural pathway for gut feelings: vagal interoceptive feedback from the gastrointestinal tract is a critical modulator of anxiety-like behavior
Krieger JP, Asker M, Van der Velden P, Börchers S, Richard JE, Maric I, Longo F, Singh A, De Larigue G, Skibicka KP (2022) Neural pathway for gut feelings: vagal interoceptive feedback from the gastrointestinal tract is a critical modulator of anxiety-like behavior. Biological Psychiatry in press. doi: 10.1016/j.biopsych.2022.04.020
Objective: To determine how the sensing of gastrointestinal state affects anxiety.
Summary: Vagal sensory signals from the gastrointestinal tract are critical for baseline and feeding-induced tuning of anxiety via the central amygdala in rats. The article results suggest vagal gut-brain signaling as a target to normalize interoception in anxiety.
Usage: 1.5 ul of CCK-SAP or Blank-SAP were delivered into each nodose ganglion at 250 ng/ul.
Featured Article: Selective ablation of IB4+ primary afferent neurons reduces mechanical and cold hyperalgesia in an EAE mouse model of multiple sclerosis
Nguyen KL, Lamerand SR, Deshpande RP, Taylor BK (2021) Featured Article: Selective ablation of IB4+ primary afferent neurons reduces mechanical and cold hyperalgesia in an EAE mouse model of multiple sclerosis. Targeting Trends 22
Jimenez-Martin J, Potapov D, Potapov K, Knöpfel T, Empson RM (2021) Cholinergic modulation of sensory processing in awake mouse cortex. Sci Rep 11(1):17525. doi: 10.1038/s41598-021-96696-8
Objective: To decipher the timing and significance of acetylcholine actions.
Summary: Study provides new insights into how the cortex processes sensory information and how loss of acetylcholine, for example in Alzheimer’s Disease, disrupts sensory behaviours.
Usage: Focal cortical injection of mu p75-SAP or Rabbit IgG-SAP (1.7 mg/ml, 0.3 µl total volume, rate 0.075 µl/minute).
The deletion of glucagon-like peptide-1 receptors expressing neurons in the dorsomedial hypothalamic nucleus disrupts the diurnal feeding pattern and induces hyperphagia and obesity
Maejima Y, Yokota S, Shimizu M, Horita S, Kobayashi D, Hazama A, Shimomura K (2021) The deletion of glucagon-like peptide-1 receptors expressing neurons in the dorsomedial hypothalamic nucleus disrupts the diurnal feeding pattern and induces hyperphagia and obesity. Nutr Metab (Lond) 18(1):58. doi: 10.1186/s12986-021-00582-z
Summary: Feeding rhythm disruption contributes to the development of obesity. GLP-1 receptors (GLP-1R) are expressed in the dorsomedial hypothalamic nucleus (DMH) which are known to be associated with thermogenesis and circadian rhythm development. These findings suggest that GLP-1R expressing neurons in the DMH may mediate feeding termination.
Usage: Exenatide-SAP targets GLP-1R expressing cells. Injections of 0.1 μg/0.5 μl Ex4-SAP or 0.1 μg/0.5 μl Blank-SAP (control) were administered into the DMH.
An acetylcholine-dopamine interaction in the nucleus accumbens and its involvement in ethanol’s dopamine-releasing effect.
Loftén A, Adermark L, Ericson M, Söderpalm B (2021) An acetylcholine-dopamine interaction in the nucleus accumbens and its involvement in ethanol’s dopamine-releasing effect. Addict Biol 26(3):e12959. doi: 10.1111/adb.12959
Summary: Basal extracellular levels of dopamine within the nucleus accumbens are not sustained by muscarinic acetylcholine, whereas accumbal Cholinergic interneurons-ACh are involved in mediating ethanol-induced dopamine release.
Usage: Anti-ChAT-SAP or Rabbit IgG-SAP were infused at a flow rate of 0.05 μl/min for 10 min giving a total volume of 0.5 μl.
Wang Z, Jiang C, Yao H, Chen O, Rahman S, Gu Y, Zhao J, Huh Y, Ji RR (2021) Central opioid receptors mediate morphine-induced itch and chronic itch via disinhibition. Brain 144(2):665-681. doi: 10.1093/brain/awaa430
Summary: Itch is a common side effect of opioids, particularly as a result of epidural or intrathecal administration. Notably, morphine-elicited itch was suppressed by intrathecal administration of NPY and abolished by spinal ablation of GRPR+ neurons with intrathecal injection of Bombesin-SAP.
Usage: For ablation of GRPR+ neurons, mice were given an intrathecal injection of 400 ng Bombesin-SAP or Blank-SAP (control) 10 days before behavioral testing.
Identification of prostaglandin F2 receptor negative regulator (PTGFRN) as an internalizable target in cancer cells for antibody-drug conjugate development
Marquez J, Dong J, Dong C, Tian C, Serrero G (2021) Identification of prostaglandin F2 receptor negative regulator (PTGFRN) as an internalizable target in cancer cells for antibody-drug conjugate development. PLoS One 16(1):e0246197. doi: 10.1371/journal.pone.0246197
Summary: PTGFRN is a cell-surface protein that is upregulated in certain cancer types, including head and neck and, notably, pediatric medulloblastoma, an aggressive cancer with limited therapeutic options. With the selection of the mouse monoclonal antibody 33B7, the authors identified PTGFRN as a potential therapy target, and show that it is internalized by incubation with 33B7. Purified 33B7 antibody was sent to Advanced Targeting Systems where saporin was directly conjugated to the Fc region of 33B7 using their proprietary cleavable linker.
Usage: In a 96-well plate, 2000 cells/well were plated in triplicate in 100 μL of DMEM/F12 medium supplemented with 2.5% FBS, 0.4 ug/ml 33B7 antibody, and 0.9ug/ml of Fab-ZAP mouse. As an isotype control, cells were incubated with mouse Fab IgG-SAP as control (instead of 33B7) and Fab-ZAP.
Oti T, Satoh K, Uta D, Nagafuchi J, Tateishi S, Ueda R, Takanami K, Young LJ, Galione A, Morris JF, Sakamoto T, Sakamoto H (2021) Oxytocin influences male sexual activity via non-synaptic axonal release in the spinal cord. Curr Biol 31(1):103-114.e5. doi: 10.1016/j.cub.2020.09.089
Summary: Oxytocin directly activates SEG (Spinal Ejaculation Generator)/GRP (Gastrin-Releasing Peptide) neurons via OXTRs (Oxytocin Receptors) and influences male sexual function in the rat lumbar spinal cord.
Usage: Oxytocin-SAP (4 or 40 ng) was infused slowly into the L3 and L4 spinal cord. Blank-SAP was used as control.
Adrenergic supersensitivity and impaired neural control of cardiac electrophysiology following regional cardiac sympathetic nerve loss
Tapa S, Wang L, Francis Stuart SD, Wang Z, Jiang Y, Habecker BA, Ripplinger CM (2020) Adrenergic supersensitivity and impaired neural control of cardiac electrophysiology following regional cardiac sympathetic nerve loss. Sci Rep 10:18801. doi: 10.1038/s41598-020-75903-y
Summary: The authors present a novel mouse model of regional cardiac sympathetic hypo-innervation utilizing Anti-DBH-SAP.
Usage: Either 5μL of 40 ng/μL Anti-DBH-SAP or Mouse IgG-SAP (control) was applied three times directly to the exposed apical/anterior surface of the heart.
Liu X, Wang D, Wen Y, Zeng L, Li Y, Tao T, Zhao Z, Tao A (2020) Spinal GRPR and NPRA contribute to chronic itch in a murine model of allergic contact dermatitis. J Invest Dermatol 140(9):1856-1866.e7. doi: 10.1016/j.jid.2020.01.016
Objective: The authors investigated the peripheral and spinal mechanisms responsible for prolonged itch in a mouse model of allergic contact dermatitis (ACD) induced by squaric acid dibutylester (SADBE).
Summary: Targeting gastrin-releasing peptide receptor (GRPR) and natriuretic peptide receptor A (NPRA) may provide effective treatments for ACD associated chronic pruritus.
Usage: A single dose of Bombesin-SAP (400 ng) and Blank-SAP (400 ng) or two doses of Nppb-SAP (BNP-SAP; 650 ng) and Blank-SAP (650 ng) were administered via intrathecal injection.
GRP receptor and AMPA receptor cooperatively regulate itch-responsive neurons in the spinal dorsal horn.
Kiguchi N, Uta D, Ding H, Uchida H, Saika F, Matsuzaki S, Fukazawa Y, Abe M, Sakimura K, Ko MC, Kishioka S (2020) GRP receptor and AMPA receptor cooperatively regulate itch-responsive neurons in the spinal dorsal horn. Neuropharmacology 170:108025. doi: 10.1016/j.neuropharm.2020.108025
Objective: To investigate the mechanisms for the activation of itch-responsive GRPR+ neurons in the spinal dorsal horn (SDH).
Summary: These findings demonstrate that GRP and glutamate cooperatively regulate GRPR+ AMPAR+ neurons in SDH, mediating itch sensation. GRP–GRPR and the glutamate–AMPAR system may play pivotal roles in the spinal transmission of itch in rodents and nonhuman primates.
Usage: Bombesin-SAP and Blank-SAP were administered i.t. (5 μg/5 μl).
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.
Cholinergic basal forebrain degeneration due to obstructive sleep apnoea increases Alzheimer’s pathology in mice.
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)
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.
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.
Evidence that the LH surge in ewes involves both neurokinin B–dependent and –independent actions of kisspeptin.
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.
Usage: Intrathecal injection
Leptin receptor-expressing neurons in ventromedial nucleus of the hypothalamus contribute to weight loss caused by fourth ventricle leptin infusions.
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).