targeted-toxins

Gravitt K, Marson L (2007) Effect of the destruction of cells containing the serotonin reuptake transporter on urethrogenital reflexes. J Sex Med 4:322-331. doi: 10.1111/j.1743-6109.2007.00436.x

Summary: Using the fact that the urethrogenital (UG) reflex is an autonomic and somatic response, the authors developed a model for ejaculatory-like reflexes. Anti-SERT-SAP (Cat. #IT-23) was bilaterally injected into the ventrolateral medulla of rats. 80 nl of a 1 µM solution removed inhibition of the UG reflex after acute spinal cord transection, while this reflex could not be evoked in control animals. The data suggest that SERT-expressing neurons in the ventral medulla are involved with the inhibition of UG reflex.

Related Products: Anti-SERT-SAP (Cat. #IT-23)

Zhao P, Waxman SG, Hains BC (2007) Extracellular signal-regulated kinase-regulated microglia-neuron signaling by prostaglandin E2 contributes to pain after spinal cord injury. J Neurosci 27:2357-2368. doi: 10.1523/JNEUROSCI.0138-07.2007 PMID: 17329433

Summary: Spinal cord injury frequently leads to the development of long-term chronic pain. Recent data has shown that activated microglia are involved in the maintenance of this pain state. Following a spinal cord contusion injury rats were treated with a 36-µg injection of Mac-1-SAP (Cat. #IT-06) into the lumbar enlargement. Treated animals were found to have reduced microglial staining, reduction in prostaglandin E2 levels, and fewer pain-related behaviors.

Related Products: Mac-1-SAP mouse/human (Cat. #IT-06), Antibody to Mac-1 (Cat. #AB-N06)

Alenda A, Nunez A (2007) Cholinergic modulation of sensory interference in rat primary somatosensory cortical neurons. Brain Res 1133:158-167. doi: 10.1016/j.brainres.2006.11.092

Summary: One critical feature of cognition is the ability to focus on selected sensory inputs while ignoring irrelevant inputs. In this work the authors examine basal forebrain participation in sensory interference effects. Following 0.15 µg bilateral injections of 192-IgG-SAP (Cat. #IT-01) into the basal forebrain of rats, the ability of primary somatosensory cortical neurons to respond in the presence of sensory interference was assessed. A decrease in the number of neurons showed sensory interference in lesioned animals.

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

Fletcher BR, Baxter MG, Guzowski JF, Shapiro ML, Rapp PR (2007) Selective cholinergic depletion of the hippocampus spares both behaviorally induced Arc transcription and spatial learning and memory. Hippocampus 17:227-234. doi: 10.1002/hipo.20261

Summary: The immediate early gene Arc is required for long-term synaptic changes and memory consolidation. The authors lesioned the fornix to examine cholinergic contributions of the medial septum and the vertical diagonal band to spatial learning impairments and behavioral induction of Arc transcription. 0.24-0.36 µg of 192-IgG-SAP (Cat. #IT-01) was delivered to the fornix of rats. Results from various water-maze tasks indicate that spatial learning deficits and impaired Arc transcription associated with lesions of the fornix are not caused by cholinergic deafferentation.

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

Maddux JM, Kerfoot EC, Chatterjee S, Holland PC (2007) Dissociation of attention in learning and action: effects of lesions of the amygdala central nucleus, medial prefrontal cortex, and posterior parietal cortex. Behav Neurosci 121(1):63-79. doi: 10.1037/0735-7044.121.1.63

Objective: To study the effect of the amygdala central nucleus (CEA) on aspects of attention.

Summary: Lesions of the cholinergic afferents of the medial prefrontal cortex interfered with five-choice serial reaction time (5CSRT) performance but not with surprise-induced enhancement of learning, whereas lesions of cholinergic afferents of posterior parietal cortex impaired the latter effects but did not affect 5CSRT performance. CEA lesions impaired performance in both tasks.

Usage: Rats received bilateral infusions of 192IgG-saporin (0.25 μg/μl) into the posterior parietal cortex.

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

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)

Dwyer TA, Servatius RJ, Pang KC (2007) Noncholinergic lesions of the medial septum impair sequential learning of different spatial locations. J Neurosci 27:299-303. doi: 10.1523/JNEUROSCI.4189-06.2007

Summary: The medial septum and the vertical limb of the diagonal band of Broca (MSDB) have extensive connections to the hippocampus. In general, impairments due to loss of cholinergic neurons in this area have been smaller than those due to the loss of noncholinergic neurons. The authors treated rats with either 192-IgG-SAP (Cat. #IT-01) or kainic acid into each hemisphere of the medial septum. Behavioral testing following surgery demonstrated that the animals with noncholinergic lesions had impaired performance, even when compared to the animals with cholinergic lesions.

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

Walker BR, Diefenbach KS, Parikh TN (2007) Inhibition within the nucleus tractus solitarius (NTS) ameliorates environmental exploration deficits due to cerebellum lesions in an animal model for autism. Behav Brain Res 176(1):109-120. doi: 10.1016/j.bbr.2006.08.008

Summary: In this work the authors use environmental exploration deficits in rats as a model for autism. Animals received 2 µg of either OX7-SAP (Cat. #IT-02) or 192-Saporin (Cat. #IT-01) into each ventricle. Only the OX7-SAP treated rats displayed a reduction in exploration behavior, and the anticonvulsant muscimol restored exploration behavior to control levels. This system may have use in controlling behavior deficits seen in autism.

Related Products: 192-IgG-SAP (Cat. #IT-01), OX7-SAP (Cat. #IT-02)

Q: Your targeted toxin kits come with different controls. I’m not sure of the best way to use them. For example, with the anti-SERT-SAP kit (Cat. # KIT-23) 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: Yes, perhaps we do have a few too many options for controls; better too many than too few. For anti-SERT-SAP, the ideal control is mouse IgG-SAP (Cat. # IT-18). Anti-SERT-SAP is made from saporin conjugated to a mouse monoclonal IgG that has SERT as its antigen. So, mouse IgG-SAP – that is, saporin conjugated to mouse IgG that has no specific antigen for targeting – would be the best control, in my mind. For years, the unconjugated antibody and unconjugated saporin mixed together was the best control available (until we came out with the “irrelevant” control immunotoxins), and still might be considered a second good control, or useful in cases where down-regulation by the antibody is a concern.

Q: What about for the peptide toxins like orexin-SAP (Cat. # IT-20) or SP-SAP (Cat. #IT-07)— what controls are available for those?

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’s like shooting blanks; 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. The best use we have seen for Blank-SAP has been in Bugarith et al. 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: Targeted Toxins, Control Conjugates

References

1. 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.