control-conjugates

Li A-J, Dinh TT, Ritter S (2007) Destruction of NPY receptor expressing neurons in the arcuate nucleus causes obesity and hyperphagia without increasing lateral hypothalamic orexigenic peptide gene expression. Neuroscience 2007 Abstracts 524.20/BBB20. Society for Neuroscience, San Diego, CA.

Summary: NPY-SAP, a conjugate of neuropeptide Y (NPY) and the ribosomal inactivating toxin, saporin (SAP), is a compound that selectively lesions NPY receptor-expressing neurons. Previously we showed that injection of NPY-SAP into the hypothalamic arcuate nucleus (ARC) induces hyperphagia and obesity in rats. To further investigate the mechanisms responsible for NPY-SAP-induced obesity, we injected NPY-SAP or blank-saporin (B-SAP) control into the ARC and subsequently examined the expression of two orexigenic neuropeptide genes in the lateral hypothalamic area (LHA), which is densely innervated by ARC neurons. Our hypothesis was that loss of leptin-sensitive neurons in the ARC in the NPY-SAP injected rats would lead to increased expression of orexigenic neurons elsewhere in the hypothalamic feeding circuitry. Body weight gain and food intake were dramatically increased in the NPY-SAP group. In addition, expression of NPY and cocaine- and amphetamine-regulated transcript (CART) mRNA was significantly reduced in the ARC of obese rats, indicating a loss of NPY receptor-expressing NPY and CART neurons in this region. In contrast, NPY and CART gene expression in the dorsomedial hypothalamic nucleus was unchanged in NPY-SAP rats, indicating that the NPY-SAP-induced lesion was limited to the ARC. However, contrary to our hypothesis, expression of the orexigenic neuronpeptides, melanin-concentrating hormone (MCH) or prepro-orexin mRNA in LHA was not enhanced, but was slightly reduced in the NPY-SAP rats. These results indicate that an enhancement of MCH or orexin expression in the LHA is not necessary for the hyperphagia and obesity observed after NPY-SAP lesions in the ARC. Supported by PHS grant #DK 40498.

Related Products: NPY-SAP (Cat. #IT-28), Blank-SAP (Cat. #IT-21)

Dias MB, Nucci TB, Margatho LO, Antunes-Rodrigues J, Gargaglioni LH, Branco LG (2007) Raphe Magnus Nucleus is involved in ventilatory but not hypothermic response to CO2. J Appl Physiol 103(5):1780-1788. doi: 10.1152/japplphysiol.00424.2007

Summary: In this work the authors investigated the role that serotonergic neurons in the Raphe Magnus Nucleus (RMg) play in ventilatory and thermal responses to hypercapnia. 0.1 µl of 1 µM anti-SERT-SAP (Cat. #IT-23) was injected into the RMg of rats. Mouse IgG-SAP (Cat. #IT-18) was used as a control. Lesioned animals had a decreased ventilatory response to CO2, but hypercapnia-induced hypothermia was not affected. The data indicate that RMg serotonergic neurons contribute to CO2 ventilatory response but not to maintenance of ventilation.

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

Schiltz JC, Sawchenko PE (2007) Specificity and generality of the involvement of catecholaminergic afferents in hypothalamic responses to immune insults. J Comp Neurol 502:455-467. doi: 10.1002/cne.21329

Summary: Interleukin-1 (IL-1) is one of the cytokines that mediates interactions between the immune system and the central nervous system. 380-ng injections of anti-DBH-SAP (Cat. #IT-03) were made into the paraventricular nucleus (PVH) of rats. Saporin (Cat. #PR-01) and mouse IgG-SAP (Cat. #IT-18) were used as controls. Lesioned animals demonstrated reduced responses to administration of IL-1, but restraint stress responses were left intact. The data suggest that ascending catecholaminergic projections mediate PVH response to IL-1.

Related Products: Anti-DBH-SAP (Cat. #IT-03), Saporin (Cat. #PR-01), Mouse IgG-SAP (Cat. #IT-18)

Truitt WA, Sajdyk TJ, Dietrich AD, Oberlin B, McDougle CJ, Shekhar A (2007) From anxiety to autism: spectrum of abnormal social behaviors modeled by progressive disruption of inhibitory neuronal function in the basolateral amygdala in Wistar rats. Psychopharmacology (Berl) 191(1):107-118. doi: 10.1007/s00213-006-0674-y

Summary: The amygdala has been identified as being involved in social behaviors. Six 4 ng injections of SSP-SAP (Cat. #IT-11) were administered bilaterally into the basolateral nucleus (BLA) of the amygdala of rats. Blank-SAP (Cat. #IT-21) was used as a control. Results of a social interaction paradigm suggest that in normal animals social inhibition can be overcome by habituation. In lesioned animals, however, social inhibition is not reversed by habituation, indicating that NK-1 receptor-expressing GABAergic interneurons in the BLA are important in this system.

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

Furlong T, Carrive P (2007) Neurotoxic lesions centered on the perifornical hypothalamus abolish the cardiovascular and behavioral responses of conditioned fear to context but not of restraint. Brain Res 1128(1):107-119. doi: 10.1016/j.brainres.2006.10.058

Summary: This work examined the role of orexin-containing neurons in the perifornical hypothalamus (PeF) during stress response. Orexin-SAP (Cat. #IT-20) or the control conjugate blank-SAP (Cat. #IT-21) was injected into the PeF of pre-conditioned rats. Tests measuring restraint and conditioned fear to context were then performed on the lesioned animals. While the lesioning was not specific enough to connect results to orexin-containing neurons, the data indicate that the PeF is critical for some forms of stress, but not others.

Related Products: Orexin-B-SAP (Cat. #IT-20), Blank-SAP (Cat. #IT-21)

Masawaki A, Sugiyo S, Shimoda T, Sakai Y, Watanabe M, Moritani M, Yoshida A, Niwa H, Takemura M (2006) Formalin-induced pain-related responses in rat lacking neurokinin-1 receptor neurons in the trigeminal nucleus caudalis. Neuroscience 2006 Abstracts 50.8. Society for Neuroscience, Atlanta, GA.

Summary: This study examines the effect of intra cisterna magna injection of substance P (SP) conjugated to saporin (SP-Sap; 5µM, 5µl) on formalin-induced pain-related behavior (PRB; face scrubbing behavior ) and c-Fos expression in the trigeminal nucleus caudalis (SpVc). In SP-Sap-treated rats, the numbers of NK-1-immunoreactive neurons in lamina I of the SpVc decreased compared with those in saline- or blank Sap-treated rats. The mean numbers ±SEM of PRB /5 min at the first phase (0-5 min after For injection) were 58.2±19.2 in the SP-Sap-treated rats, 115.6±14.0 in the saline treated rats and 86.9±45.7 in the blank-Sap-treated rats. The numbers at the quiescent period (5-10 min) were 45.2±26.3 in the SP-Sap- treated rats, 93.6±26.5 in the saline treated rats and 69.4±16.3 in the blank-Sap-treated rats. These at the former second phase (10-50 min) were 58.1±22.3 in the SP-Sap-treated rats, 133.6±26.1 in the saline treated rats and 95.8±29.6in the blank-Sap-treated rats. These at the latter second phase (55-90 min) were 7.0±5.6 in the SP-Sap-treated rats,13.7±12.4 in the saline treated rats and 10.4±22.5 in the blank-Sap-treated rats. These results indicate that formalin-induced nociceptive responses in the SP-Sap-treated rats are reduced.

Related Products: SP-SAP (Cat. #IT-07), Blank-SAP (Cat. #IT-21)

Bugarith K, Dinh TT, Li AJ, Speth RC, Ritter S (2006) Featured Article: Basomedial hypothalamic injections of neuropeptide Y conjugated to saporin selectively disrupt hypothalamic controls of food intake. Targeting Trends 7(4)

Related Products: Anti-DBH-SAP (Cat. #IT-03), NPY-SAP (Cat. #IT-28), Saporin (Cat. #PR-01), Blank-SAP (Cat. #IT-21)

Read the featured article in Targeting Trends.

See Also:

• 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.

Nattie E, Li A (2006) Neurokinin-1 receptor expressing neurons in the ventral medulla are essential for normal central and peripheral chemoreception in the conscious rat. J Appl Physiol 101(6):1596-1606. doi: 10.1152/japplphysiol.00347.2006

Summary: All known chemoreceptor sites in the mammalian brainstem are rich in the neurokinin-1 receptor (NK1r). The authors ask if these cells scattered throughout the ventral medulla are involved in central and peripheral chemoreception. Rats received 250-280 ng of SSP-SAP (Cat. #IT-11) into the cisterna magna, mouse IgG-SAP (Cat. #IT-18) was used as a control. The results indicate that NK1r neurons in the ventral medulla are involved in both central and peripheral chemoreception, during both waking and sleep states.

Related Products: SSP-SAP (Cat. #IT-11), Mouse IgG-SAP (Cat. #IT-18)

Kohls M (2006) Evaluate Potential Targeting Molecules. Nature Methods

Summary: Targeted toxins — targeting agents conjugated to saporin — are widely used to eliminate specific cell populations both in vitro and in vivo. For these molecules to be effective, it is vital that the targeting component of the conjugate specifically binds the cells of interest. A secondary conjugate, Streptavidin-ZAP, has been created by attaching the toxin saporin to streptavidin. The user can combine primary biotinylated material with Streptavidin-ZAP to quickly and economically screen potential targeting molecules for internalization and specificity. Once the appropriate targeting molecule is identified, a direct conjugation with saporin can be performed.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Read the article.

Parikh V, Sarter M (2006) Cortical choline transporter function measured in vivo using choline-sensitive microelectrodes: clearance of endogenous and exogenous choline and effects of removal of cholinergic terminals. J Neurochem 97(2):488-503. doi: 10.1111/j.1471-4159.2006.03766.x

Summary: A major projection of brain attention systems passes through the cholinergic portion of the cortical mantle. The authors investigated the role of high-affinity choline transporters (CHT) in the clearance of exogenous choline, as well as choline from newly released acetylcholine. 0.085 µg of 192-IgG-SAP (Cat. #IT-01) was injected into each hemisphere of the basal forebrain of rats (mouse IgG-SAP, Cat. #IT-18, was used as a control). The results demonstrate that no matter the source, increases in choline concentrations are cleared by CHT’s.

Related Products: 192-IgG-SAP (Cat. #IT-01), Mouse IgG-SAP (Cat. #IT-18)