control-conjugates

Holschbach MA, Vitale EM, Lonstein JS (2018) Serotonin-specific lesions of the dorsal raphe disrupt maternal aggression and caregiving in postpartum rats. Behav Brain Res 348:53-64. doi: 10.1016/j.bbr.2018.04.008

Objective: To determine the effects of behavioral modifications associated with early motherhood by permanently disrupting serotonin signaling at one of its primary sources, the dorsal raphe (DR).

Summary: Prepartum serotonin-specific lesions of the DRdm impaired maternal aggression. Larger postpartum DR serotonin lesions affected both aggression and caregiving. DR serotonin lesions did not affect postpartum anxiety.

Usage: 1 μL of 0.1M anti-SERT-SAP or control Mouse IgG-SAP was slowly infused into the DR.

Related Products: Anti-SERT-SAP (Cat. #IT-23), Mouse IgG-SAP (Cat. #IT-18)

Zhang Q, De Corte B, Jung D, Kim Y, Geerling J, Narayanan N (2018) Cholinergic modulation targeting medial prefrontal cortex leads to behavior deficit in interval timing task. Neurology 90 (15 Supplement):P5.195.

Objective: To determine the effect of cholinergic lesion targeting medial prefrontal cortex on interval timing behavior.

Summary: Mice receiving medial prefrontal mu-p75-saporin injection performed poorly compared to control mice in interval timing task. Cholinergic lesion targeting medial prefrontal cortex caused interval timing behavior deficit in wild type mice.

Usage: mu-p75-SAP, a toxin targeting cholinergic neurons, into the bilateral medial prefrontal cortical regions of wild type mice pre-trained in interval timing task. Control mice (also pre-trained in interval timing task, n=8) received stereotactic injection of Rabbit IgG-SAP.

Related Products: mu p75-SAP (Cat. #IT-16), Rabbit IgG-SAP (Cat. #IT-35)

Strichartz G, Khasabov S, Barr T, Wang J, Simone D (2018) Modulation of chronic post-thoracotomy pain by NK-1 neurons in the rostral ventromedial medulla is not paralleled by changes spinal MAPKinase activation. J Pain 19:S14. doi: 10.1016/j.jpain.2017.12.065

Objective: To evaluate SSP-SAP in treatment of tactile hypersensitivity for Chronic Post-Thoractotomy Pain (CPTP).

Summary: SSP-SAP 3 weeks before thoracotomy and rib retraction (TRR) was able to completely prevent CPTP, assayed by tactile hypersensitivity.

Usage: Ablation of Neurokinin-1 receptor (NK-1R)- expressing neurons in the rat rostral ventromedial medulla (RVM), by micro-injection of the specific neurotoxin SSP-SAP.  No effect with treatment of control, Blank-SAP (IT-21).

Related Products: SSP-SAP (Cat. #IT-11), Blank-SAP (Cat. #IT-21)

Turnbull MT, Boskovic Z, Coulson EJ (2018) Acute down-regulation of BDNF signaling does not replicate exacerbated amyloid-β levels and cognitive impairment induced by cholinergic basal forebrain lesion. Front Mol Neurosci 11:51. doi: 10.3389/fnmol.2018.00051

Objective: To determine if degeneration of BFCNs causes a decrease in neurotrophin levels in innervated brain areas, which in turn promotes the development of Amyloid beta  pathology and cognitive impairment.

Summary: Lesion of septo-hippocampal BFCNs in a pre-symptomatic transgenic amyloid AD mouse model (APP/PS1 mice) increases soluble Ab levels in the hippocampus, and induces cognitive deficits in a spatial memory task that are not seen in either unlesioned APP/PS1 or non-transgenic littermate control mice. Cognitive decline and Amyloid-beta pathology induced by cholinergic basal forebrain neuron loss occur independent of dysfunctional neuronal BDNF signaling, and may therefore be directly underpinned by reduced cholinergic neurotransmission.

Usage: To lesion BFCNs, a single infusion of murine p75-SAP or control rabbit IgG-SAP (0.4 mg/ml) was stereotaxically injected into the basal forebrain.

Related Products: mu p75-SAP (Cat. #IT-16), Rabbit IgG-SAP (Cat. #IT-35)

Lee SJ, Jokiaho AJ, Sanchez-Watts G, Watts AG (2018) Catecholaminergic projections into an interconnected forebrain network control the sensitivity of male rats to diet-induced obesity. Am J Physiol Regul Integr Comp Physiol 314(6):R811-R823. doi: 10.1152/ajpregu.00423.2017

Objective: To investigate the role of hindbrain catecholamine neuron pathways and their contribution to long-term energy homeostasis by controlling obesogenic sensitivity to a high-fat, high sucrose choice diet.

Summary: The authors show that catecholamine neurons (primarily in the VLM and NTS) convey essential feedback signals to enable long-term adaptive control of energy metabolism when animals consume a predominantly carbohydrate diet. This is the first report specifically associating this projection system with the long-term control of adiposity.

Usage: Catecholaminergic projections to the PVH and related parts of the forebrain were lesioned with bilateral injections each consisting of 42 ng/200 nL of Anti-DBH-SAP or equimolar amounts of control Mouse IgG-SAP.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Mouse IgG-SAP (Cat. #IT-18)

Mu D, Sun Y-G (2017) Itch induces conditioned place aversion in mice. Neuroscience Letters 658:91-96.. doi: 10.1016/j.neulet.2017.08.046

Summary: Consistently, ablation of itch‐specific neurons that express gastrin‐releasing peptide receptor in the spinal cord also abolished itch‐induced Conditioned Place Aversion (CPA), confirming that itch‐induced CPA is dependent on the spinal itch circuit.

Usage: Mice were given a single intrathecal injection (400 ng/5 μl each) of Bombesin-SAP (Cat. #IT-40) or Control Blank-SAP (Cat. #IT-21).

Related Products: Bombesin-SAP (Cat. #IT-40), Blank-SAP (Cat. #IT-21)

Fu C, Xue J, Wang R, Chen J, Ma L, Liu Y, Wang X, Guo F, Zhang Y, Zhang X, Wang S (2017) Chemosensitive Phox2b-expressing neurons are crucial for hypercapnic ventilatory response in the nucleus tractus solitarius. J Physiol 595:4973-4989.. doi: 10.1113/JP274437

Objective: To investigate whether paired-like homeobox 2b  (Phox2b)-expressing NTS neurons are recruited in hypercapnic ventilatory response (HCVR)  and whether these neurons exhibit intrinsic chemosensitivity.

Summary: Respiratory deficits caused by injection of SSP-SAP into the NTS are attributable to proportional lesions of CO2/H+-sensitive Phox2b-expressing neurons.

Usage: Two protocols were applied for SSP-SAP injections. In immunostaining experiments, to determine how many Phox2b-containing cells were destroyed, a total volume of 100 nl of PBS containing 6 ng of SSP-SAP (3 ng in 50 nl; 2 injections) was injected into one side of the NTS and the contralateral NTS was used as a control (no injection).  For in vivo experiments, to determine whether loss of Phox2b cells led to impaired HCVR, bilateral injections with a total volume of 200 nl of PBS containing 6 ng (1.5 ng in 50 nl per injection; 2 injections per side) or 12 ng (3 ng in 50 nl per injection; two injections per side) of toxin into NTS.  Breathing was studied in conscious, freely moving mice treated with SSP-SAP and Blank-SAP.

Related Products: SSP-SAP (Cat. #IT-11), Blank-SAP (Cat. #IT-21)

Q: Your targeted toxin kits come with different controls. I’m not sure of the best way to use them; there is included unconjugated antibody, unconjugated saporin, and a control conjugate, mouse IgG-SAP. Should I use them all in the same experiment or for different purposes?

A: For mouse IgG-containing conjugates, the ideal control is Mouse IgG-SAP (Cat. # IT-18). Mouse IgG-SAP — that is, saporin conjugated to mouse IgG — that has no specific antigen for targeting is the best control. Unconjugated saporin is still considered a second good control, useful in cases where down-regulation by the antibody is a concern.

Q: What about for the peptide toxins?

A: We have produced Blank-SAP as a control for the peptide ligand toxins. Blank-SAP (Cat. #IT-21) is a peptide that has the usual common amino acids that are found in peptide neurotransmitters, but arranged in a sequence that is random and not detected in homology searches. So, it should never find an amenable receptor.  This is quite an important control; the peptide ligand toxins are often delivered directly to tissue, and there are cases in which there will be no toxicity or non-specific toxicity.

One of the best uses we have seen for Blank-SAP has been in: Bugarith K et al. Basomedial hypothalamic injections of neuropeptide Y conjugated to saporin selectively disrupt hypothalamic controls of food intake. Endocrinology 146(3):1179-1191, 2005.

As any journal reviewer will tell you, it’s very important to document the specificity, and with Blank-SAP as a control, you can definitively show that toxicity is due to proper targeting, rather than non-specific cytotoxicity. This should provide the information needed so the reviewer doesn’t have to make you go back and document specificity with further experimental work!

See a complete list of control conjugates here.

Havelin J, Imbert I, Sukhtankar D, Remeniuk B, Pelletier I, Gentry J, Okun A, Tiutan T, Porreca F, King T (2017) Mediation of movement-induced breakthrough cancer pain by IB4-binding nociceptors in rats. J Neurosci 37:5111-5122.. doi: 10.1523/JNEUROSCI.1212-16.2017

Objective: To define a novel preclinical measure of movement-induced breakthrough pain (BTP) that is observed in the presence of morphine controlling ongoing pain.

Summary: Novel compounds targeting IB4-binding nociceptors may improve pain management for cancer pain patients and other patient populations suffering from BTP that is inadequately treated by currently available medications.

Usage: To determine the effect of eliminating input from IB4-binding fibers, separate groups of rats received spinal administration of IB4-SAP or the control, Blank-SAP (3.2 mcg/20 mcl saline) followed by a 10 mcl flush of saline. Movement of an air bubble placed between drug solution and saline was used to monitor progress of the injection.

Related Products: IB4-SAP (Cat. #IT-10), Blank-SAP (Cat. #IT-21)

Ye J-H, Fu R, He W (2017) The rostromedial tegmental nucleus and alcohol addiction. Oncotarget 8:18624-18625.. doi: 10.18632/oncotarget.15822

Summary: The authors discuss their work with Dermorphin-SAP (Cat. #IT-12) and their demonstration that damage of RMTg MOR-expressing GABAergic neurons by Dermorphin-SAP increased the intake and preference for alcohol, boosted the expression and slowed down the extinction of alcohol conditioned place preference, and increased locomotion. Microinjection of DS into the RMTg substantially reduced the number of RMTg cells. Importantly, the rats that received DS injection elevated their alcohol intake and preference compared to those that received an injection of Blank-SAP (Cat. #IT-21), which did not cause neuronal damage.

Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Blank-SAP (Cat. #IT-21)