saporin

Harasawa I, Johansen J, Fields H, Porreca F, Meng I (2016) Alterations in the rostral ventromedial medulla after the selective ablation of μ-opioid receptor expressing neurons. Pain 157:166-173. doi: 10.1097/j.pain.0000000000000344

Summary: The rostral ventromedial medulla (RVM) has both excitatory and inhibitory control over nociceptive neurons in the medullary dorsal horn and spinal cord. Previous work has demonstrated that elimination of mu-opioid receptor-expressing neurons in the RVM reduces stress and injury-induced behavioral hypersensitivity, but the effect of losing these cells on the descending inhibitory system has not been examined. The authors administered 1.2 pmol of Dermorphin-SAP (Cat. #IT-12) to each side of the RVM of rats. Saporin (Cat. #PR-01) was used as a control. Characterization of RVM neurons in lesioned animals showed a reduction in on- and off-cells, but no change in the number of neutral cells. These data indicate that mu-opioid receptor-expressing cells in the RVM are not needed for analgesia produced by activation of RVM neurons.

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

Ostock CY, Conti MM, Larose T, Meadows S, Bishop C (2015) Cognitive and motor deficits in a rodent model of Parkinson’s disease displaying concurrent dopamine and acetylcholine loss. Neuroscience 2015 Abstracts 676.26/D33. Society for Neuroscience, Chicago IL.

Summary: Dopamine (DA) loss in Parkinson’s disease (PD) is frequently accompanied by degeneration of acetylcholine neurons within the basal forebrain (BF) and the pedunculopontine nucleus (PPN). Recently, Ach neurons in these nuclei have been implicated in both the motor and non-motor symptoms of PD. However, few rodent models of PD actually account for Ach loss in both the BF and PPN. Here, we evaluated the effects of concurrent BF and PPN Ach loss alone and in combination with striatal DA loss on motor and cognitive performance in a rat model of PD. Sprague-Dawley rats (N = 44) received bilateral: striatal 6-OHDA lesions to deplete DA (DA-lesioned; n = 14), BF (192 IgG-Saporin) and PPN (anti-ChAT Saporin) saporin lesions to deplete Ach (Ach-lesioned; n = 10), combined 6-OHDA + saporin lesions (dual-lesioned; n = 6) , or sham lesions (n = 14). Following recovery from surgery, rats underwent a battery of motor and cognitive behavioral tests. Results indicated that Ach-lesioned and dual-lesioned rats displayed spatial memory deficits on the Morris Water Maze and Spontaneous Alternation tests. DA and Ach lesions alone impaired stepping for the forepaw adjusting steps and vibrissae-elicited paw placement tests and this deficit was exacerbated in dual-lesioned rats. However, only rats with Ach or dual lesions showed motor deficits on the rotarod tests. Collectively, these findings demonstrate that Ach loss may exacerbate cognitive and motor symptoms in PD and highlight the importance of including Ach loss in preclinical models of PD.

Related Products: 192-IgG-SAP (Cat. #IT-01), Anti-ChAT-SAP (Cat. #IT-42), Saporin (Cat. #PR-01)

Alenciks E, Frazier K, Porter A, Fraley G (2015) Immunolesions of melanopsin receptive neurons attenuates the hormonal reproductive axis in the adult but has no effect on growth in immature Peking ducks. Neuroscience 2015 Abstracts 613.05/R20. Society for Neuroscience, Chicago IL.

Summary: Several light sensitive receptors have been described in the avian brain that are thought to regulate the reproductive axis independently from the eyes and pineal gland. Recently, our lab has described the presence of 3 photoneuroendocrine systems in the Pekin duck: rhodopsin, opsin 5, & melanopsin. We set out to test the hypothesis that melanopsin receptive neurons are necessary to maintain seasonal reproductive status along with growth and development in the Pekin drake. To accomplish these goals we first investigated 50-week-old Pekin drakes that were housed in the aviary at Hope College under long day length (18 hrs lights on) conditions in floor pens. To specifically lesion melanopsin-receptive neurons, 3 μl of an anti-melanopsin-saporin conjugate (MSAP, 100 ng/ul) was injected into the lateral ventricle (n = 10). Control drakes were injected with 3 ul of equimolar unconjugated anti-melanopsin and saporin (SAP, n = 10). The drakes were returned to the aviary after complete recovery. Reproductive behaviors were analyzed weekly in a test pen with adult hens. After 4 weeks, birds were euthanized and body weights were measured, and brains, pituitaries, and testes collected and stored for analyses. To test melanopsin’s effect on immature ducks the same surgery was performed on a group of 10 day old ducks (n= 10). Ducks were weighed weekly starting at 3 days of age. After a final weight was obtained at 50 days of age, ducks were euthanized and a blood sample was collected and sent out for an avian panel. Mature MSAP-treated drakes had significantly (p< 0.001) reduced relative teste weights compared to SAP controls. qRT-PCR analyses (n= 3 per treatment) of anterior pituitary showed a significant reduction (p< 0.001) in both LH-beta and FSH mRNA’s. Immunoctyochemical analyses (n= 3 per treatment) showed a significant reduction in melanopsin and GnRH-immunoreactivities. Immature drake BW did not differ significantly between MSAP and SAP animals at any of the measured days. The data appeared to drift toward significance near the end of the sampling period (p = 0.297). Blood panel results revealed no significant differences between MSAP and SAP animals in any CBC component. Serum glutamic-oxaloacetic transaminase (SGOT) (p= 0.022) and creatine phosphokinase (CPK) values were significantly elevated (p = 0.006) in MSAP animals compared to controls. Although melanopsin neurons in the PMM appear to have an important role in adult drakes, their importance in the growth of immature ducks is still unclear. However, these data underscore the importance of the photoneuroendocrine system in maintaining the reproductive axis along with growth and development in seasonally breeding birds.

Related Products: Melanopsin-SAP (Cat. #IT-44), Saporin (Cat. #PR-01)

Porter LM, Alenciks E, Frazier K, Porter A, Fraley GS (2015) Lack of effects on growth and body weight gain after elimination of the leptin receptor from the brain of immature Pekin drakes. Neuroscience 2015 Abstracts 613.04/R19. Society for Neuroscience, Chicago IL.

Summary: The presence of the hormone leptin (LEP) is a controversial topic in the field of avian physiology. While LEP is well understood in mammals, the hormone has not been definitively verified in avian species. Although the hormone remains elusive, the leptin receptor (LEPR) has been identified and sequenced in multiple avian species. Its role, however, remains unclear. To attempt to deduce the role of the leptin system in birds, we focused on altering the leptin receptor expression in the brain of immature Pekin ducks. We hypothesized that eliminating the LEPR-expressing neurons of the hypothalamus would elicit an increase in body weight, as is the case for mammals. To test this hypothesis, we injected stereotaxically 3 ul of a solution containing a monoclonal antibody (anti-LEPR) conjugated to saporin (LSAP, 100 ng/ul) was injected into the lateral ventricle of 10 day old Pekin ducks (LSAP, N = 10). Control group animals (SAP) were injected with unconjugated antibody and saporin at equimolar concentrations to the LSAP. Ducks were weighed weekly starting at 3 days of age. After a final weight was obtained at 50 days of age, ducks were euthanized and a blood sample was collected and sent out for an avian panel to assay serum glucose and free fatty acids. We found that the elimination of LEPR had no significant effect on the body weights of the ducks (p>0.05). In addition, The CBC panel did not reveal any significant differences in the overall health of the ducks in each treatment group. Our data indicates LEPR may not play a significant role in the regulation of body weight or growth in juvenile ducks.

Related Products: Custom Conjugates, Saporin (Cat. #PR-01)

Q: I’m trying to find out if enough Anti-DBH-SAP will be retrogradely transported and taken up by non targeted sympathetic neurons by bulk fluid-phase endocytosis. Does saporin become degraded after it kills the neuron or does it enter the extracellular matrix?

A: It is very unlikely that a targeted toxin such as Anti-DBH-SAP is freed from the targeted neuron in a meaningful condition. There has never been a reported identification of a targeted toxin, functionally or not, after it has eliminated its targeted neuron. Current evidence indicates that effective suicide transport agents undergo endocytosis at nerve terminals followed by retrograde axonal transport of the endocytic vesicles containing the toxin. Experiments using vincristine have shown that the retrograde axonal transport of suicide transport toxins utilizes the fast transport system (microtubules). However, it is not known what determines whether or not a specific toxin-ligand undergoes axonal transport after internalization.

Related Products: Anti-DBH-SAP (Cat. #IT-03)

Devoto P, Flore G, Saba P, Frau R, Gessa G (2015) Selective inhibition of dopamine-beta-hydroxylase enhances dopamine release from noradrenergic terminals in the medial prefrontal cortex. Brain Behav 5:e00393. doi: 10.1002/brb3.393

Summary: Dopamine-beta-hydroxylase (DBH) is a neuronal enzyme that is a potential target for the treatment of cocaine abuse, alcohol dependence, and eating disorders. Here the authors administered 5 μg of icv Anti-DBH-SAP (Cat. #IT-03) to rats, and assessed the effect of the dopaminergic lesion on levels of extracellular dopamine. Mouse IgG-SAP (Cat. #IT-18) and saporin (Cat. #PR-01) were used as controls. Extracellular levels of dopamine were significantly increased in both lesioned animals and those treated with the DBH inhibitor nepicastat. Clonadine could reverse the nepicastat effect, but not the effect of Anti-DBH-SAP treatement. The data demonstrate a mechanism for the synergistic effect of cocaine on nepicastat-induced dopamine release.

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

Kras J, Weisshaar C, Pall P, Winkelstein B (2015) Pain from intra-articular NGF or joint injury in the rat requires contributions from peptidergic joint afferents. Neurosci Lett 604:193-198. doi: 10.1016/j.neulet.2015.07.043

Summary: Both peptidergic and non-peptidergic neurons innervate the facet joint, which is the source of pain in a majority of neck trauma. In this work the authors examined these subpopulations of neurons to determine the contribution of each in facet joint pain. 100 ng of SSP-SAP (Cat. #IT-11) was injected into bilateral C6/C7 facet joints of rats. Alternatively, rats received 5 μg of rIB4-SAP (Cat. #IT-10) via the same method. Saporin (Cat. #PR-01) was used as control. SSP-SAP, but not rIB4-SAP was able to prevent NGF-induced mechanical and thermal hypersensitivity. SSP-SAP administration also prevented behavioral hypersensitivity and NGF upregulation in the dorsal root ganglion after facet joint distraction. The data indicate that interference with peptidergic signaling within the facet joint may be a treatment for pain originating in that location.

Related Products: SSP-SAP (Cat. #IT-11), IB4-SAP (Cat. #IT-10), Saporin (Cat. #PR-01)

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

Summary: Stereotypy is defined as abnormally repetitive motor movements accompanied by an inability to initiate normal adaptive responses. Psychostimulants such as cocaine will often produce these movements. It is thought that stereotypy is related to activation of the patch compartment of the striatum. In order to better understand the function of the patch compartment in stereotypy due to repeated exposure to cocaine, the authors administered bilateral injections of Dermorphin-SAP (Cat. #IT-12) into the rostral striatum. Saporin (Cat. #PR-01) was used as a control.

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

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)

Sorge R, Mapplebeck J, Rosen S, Beggs S, Taves S, Alexander J, Martin L, Austin J, Sotocinal S, Chen D, Yang M, Shi X, Huang H, Pillon N, Bilan P, Tu Y, Klip A, Ji R, Zhang J, Salter M, Mogil J (2015) Different immune cells mediate mechanical pain hypersensitivity in male and female mice. Nat Neurosci 18:1081-1083. doi: 10.1038/nn.4053

Summary: A large and rapidly increasing body of evidence indicates that microglia-to-neuron signaling is essential for chronic pain hypersensitivity. Using multiple approaches, the authors found that microglia are not required for mechanical pain hypersensitivity in female mice; female mice achieved similar levels of pain hypersensitivity using adaptive immune cells, likely T lymphocytes. This sexual dimorphism suggests that male mice cannot be used as proxies for females in pain research. Mac-1-SAP mouse/human toxin (Cat. #IT-06, 15 μg in 8.8 μl) and Saporin control (Cat. #PR-01, 8.8 μg in 8.8 μl) were administered via i.t. injection. The topic of immune system involvement in chronic pain pathophysiology is one of the most active in the pain field; that this sex difference has not been observed until now is very surprising indeed. An important implication of the current findings is that distinct strategies targeting neuroimmune signaling might be required for the treatment of chronic pain in men versus women.

Related Products: Mac-1-SAP mouse/human (Cat. #IT-06), Saporin (Cat. #PR-01)