targeted-toxins

Araldi D, Ferrari L, Levine J (2015) Repeated mu-opioid exposure induces a novel form of the hyperalgesic priming model for transition to chronic pain. J Neurosci 35:12502-12517. doi: 10.1523/JNEUROSCI.1673-15.2015

Summary: Repeated administration of mu-opioid receptor agonists can lead to persistent mechanical hyperalgesia. One current hypothesis is that a form of hyperalgesic priming is triggered by the repeated activation of these receptors. Classic hyperalgesic priming is associated with signaling via protein kinase Cε (PKε), which is mediated by isolectin-B4+ (IB4) nociceptors. In this work the authors eliminated the IB4+ nociceptors with a 3.2 μg intrathecal injection of recombinant IB4-SAP (Cat. #IT-10). The authors found that hyperalgesic priming induced through the use of DAMGO was dependent on protein kinase A activation rather than activation of PKε. This work demonstrates a novel model for hyperalgesic priming transitioning to chronic pain.

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

Apps R, Strata P (2015) Neuronal circuits for fear and anxiety – the missing link. Nat Rev Neurosci 16(10):642. doi: 10.1038/nrn4028 PMID: 26333516

Objective: To study the active role of the cerebellar network in conditioned and unconditioned fear by quantifying the connection of cerebellar cortical areas to emotional driven responses.

Summary: The article seeks to quantify the connection of cerebellar cortical areas like the prefrontal cortex to emotional driven responses, like the freezing associated with fearful stimuli. CTB-SAP lesioned rats, causing localized cell death in the fear associated regions of the brain being studied, are compared to sham-lesioned rats and the length of freezing time as a response to a negatively-percevied auditory tone and cat-odor.

Usage: Rats received microinjections of the neurotoxin CTB–Saporin into the vermal lobule VIII which resulted in a localized lesion of cerebellar cortical connections.

Related Products: CTB-SAP (Cat. #IT-14)

Murray R, Logan M, Horner K (2015) Striatal patch compartment lesions reduce stereotypy following repeated cocaine administration. Brain Res 1618:286-298. doi: 10.1016/j.brainres.2015.06.012 PMID: 26100338

Objective: Investigate the impact of neuron ablation in the striatum on stereotypy, a form of repetitive and uncontrollable behavior, in rats following cocaine administration.

Summary: Stereotypy, characterized by rigid, repetitive behaviors after psychostimulant exposure, is linked to the activation of the patch compartment within the striatum. To clarify the role of these neurons, they were selectively ablated, resulting in a noticeable reduction in the intensity of stereotypy behaviors.

Usage: 2 microliters of Dermorphin-SAP (IT-12) at a concentration of 17 ng/μl were administered bilaterally into the patch compartment of the striatum. Saporin (Cat. #PR-01) was used as a control.

Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12), Saporin (Cat. #PR-01)

See Also:

• Saporin (Cat. #PR-01) was used as a control.

Li A, Wang Q, Davis H, Wang R, Ritter S (2015) Orexin-A enhances feeding in male rats by activating hindbrain catecholamine neurons. Am J Physiol Regul Integr Comp Physiol 309:R358-367. doi: 10.1152/ajpregu.00065.2015

Summary: Although administration of orexin, norepinephrine, and epinephrine all induce significantly increased food intake, the potential interaction between the networks affected by these molecules has not been studied. In this work, the authors investigate the hypothesis that orexin neurons may stimulate feeding through the activation of catecholamine neurons. Rats received 82-ng injections of Anti-DBH-SAP (Cat. #IT-03) into the hypothalamus in order to lesion hypothalamically-projecting catecholamine neurons. Saporin (Cat. #PR-01) was used as a control. While the normal response to orexin A is increased food intake, lesioned animals did not display this response, indicating that catecholamine neurons are necessary for orexin modulation of food intake.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Saporin (Cat. #PR-01)

Li J, Pan Y, Zhang B, Chen Q (2015) Macrophages are needed in the progression of tuberculosis into lung cancer. Tumour Biol 36:6063-6066. doi: 10.1007/s13277-015-3283-8

Summary: Approximately 30% of lung carcinomas also have tuberculosis lesions. The authors investigated the potential link between inflammatory processes and cancer in the lung. Mice with established tuberculosis infections received weekly 20 μg tail vein injections of Mac-1-SAP (Cat. #IT-06) in order to eliminate macrophages. Six months later the mice receiving Mac-1-SAP had a significantly lower incidence of lung carcinoma than control animals.

Related Products: Mac-1-SAP mouse/human (Cat. #IT-06)

McHugh S, Francis A, McAuley J, Stewart A, Baxter M, Bannerman D (2015) Hippocampal acetylcholine depletion has no effect on anxiety, spatial novelty preference, or differential reward for low rates of responding (DRL) performance in rats. Behav Neurosci 129:491-501. doi: 10.1037/bne0000072

Summary: It is unclear whether cholinergic lesions in the hippocampus affect both learning and behavior, or learning only. In this study the authors lesioned cholinergic neurons in the medial septum/vertical limb of the diagonal band of Broca of rats with bilateral 30-ng injections of 192-IgG-SAP (Cat. #IT-01). Although hippocampal cholinergic innervations were significantly reduced, with a concomitant reduction in choline acetyltransferase activity, the lesioned animals did not perform differently in several behavioral tests. The data do not provide evidence that the septo-hippocampal cholingeric projections play a role in anxiety, spatial novelty preference, or differential reward for low rates of responding tests.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Xing D, Wu Y, Li G, Song S, Liu Y, Liu H, Wang X, Fei Y, Zhang C, Li Y, Zhang L (2015) Role of cerebrospinal fluid-contacting nucleus in sodium sensing and sodium appetite. Physiol Behav 147:291-299. doi: 10.1016/j.physbeh.2015.04.034

Summary: Sodium concentration in the cerebrospinal fluid (CSF) is tightly regulated, and this regulation requires numerous sensors spread throughout the brain. Here the authors injected 900 ng CTB-SAP (Cat. #IT-14) into the lateral ventricles. Investigation of spontaneous and induced sodium intake indicates the CSF-contacting nucleus is an important link in the sodium sensing network, and interacts with the lateral parabrachial nucleus.

Related Products: CTB-SAP (Cat. #IT-14)

Oyamaguchi A, Abe T, Sugiyo S, Niwa H, Takemura M (2016) Selective elimination of isolectin B4-binding trigeminal neurons enhanced formalin-induced nocifensive behavior in the upper lip of rats and c-Fos expression in the trigeminal subnucleus caudalis. Neurosci Res 103:40-47. doi: 10.1016/j.neures.2015.07.007

Summary: In adult rats non-peptidergic neurons and peptidergic neurons innervate different areas and layers of the lamina. It is thought that these two neuronal populations play different roles in nociceptive processing, but the specific function of each group is not well understood. In order to investigate peptidergic and non-peptidergic neurons in orofacial pain processing the authors injected the cisterna magna of rats with 2.9 μg of rIB4-SAP (Cat. #IT-10). Blank-SAP (Cat. #IT-21) was used as a control. The lesioned animals displayed more frequent face-rubbing responses on the administration of formalin, indicating that IB4-binding neurons in the trigeminal nerve play an anti-nociceptive role in response to this type of pain.

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

King T, Ruyle B, Kline D, Heesch C, Hasser E (2015) Catecholaminergic neurons projecting to the paraventricular nucleus of the hypothalamus are essential for cardiorespiratory adjustments to hypoxia. Am J Physiol Regul Integr Comp Physiol 309:R721-731. doi: 10.1152/ajpregu.00540.2014

Summary: Catecholaminergic neurons in the brainstem are known to be involved in cardiorespiratory control and to modulate sensory function. Some of the projections from these neurons are to the paraventricular nucleus (PVN), and are involved in cardiorespiratory and neuroendocrine responses to hypoxia. While data have shown the PVN-projecting neurons are activated by hypoxia, their function in this context is not known. In this work the authors bilaterally injected 42 ng of Anti-DBH-SAP (Cat. #IT-03) into the PVN of rats. Mouse IgG-SAP (Cat. #IT-18) was used as control. Respiratory measurements of the lesioned animals indicates that PVN-projecting catecholaminergic neurons are involved in peripheral and central chemoreflex and arterial oxygen levels during exposure to hypoxic stimuli.

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

Noe C, McDermott E (2015) Featured Article: SP-SAP human clinical trial for cancer pain – an anesthesiologist’s point of view. Targeting Trends 16(3)

Related Products: SP-SAP (Cat. #IT-07)

Read the featured article in Targeting Trends.