control-conjugates

Matsuura T, Kawasaki M, Hashimoto H, Yoshimura M, Motojima Y, Saito R, Ueno H, Maruyama T, Sabanai K, Mori T, Ohnishi H, Sakai A, Ueta Y (2016) Effects of central administration of oxytocin-saporin cytotoxin on chronic inflammation and feeding/drinking behaviors in adjuvant arthritic rats. Neurosci Lett 621:104-110. doi: 10.1016/j.neulet.2016.04.010

Summary: In the present study, Oxytocin-SAP, which chemically disrupts oxytocin (OXT signaling was administered centrally and an OXT receptor (OXTR) antagonist administered peripherally to determine whether central and peripheral OXT is involved in chronic inflammation and feeding/drinking behavior in adjuvant arthritis (AA) rats. Rats were injected i.t. with Oxytocin-SAP (Cat. #IT-46) or Blank-SAP (Cat. #IT-21) dissolved in saline (0.06 μg/μl). The results demonstrated that the arthritis index values were significantly enhanced and suppression of food intake was transiently attenuated in Oxytocin-SAP treated rats when AA developed, The arthritis index and food intake did not significantly change in the OXTR antagonist i.p.-injected rats. These results suggest that central oxytocinergic pathways may be involved in anti-inflammation at the spinal level and suppression of feeding behavior at the forebrain-brainstem level in AA rats.

Related Products: Oxytocin-SAP (Cat. #IT-46), Blank-SAP (Cat. #IT-21)

Angioni L, Cocco C, Ferri G, Argiolas A, Melis M, Sanna F (2016) Involvement of nigral oxytocin in locomotor activity: A behavioral, immunohistochemical and lesion study in male rats. Horm Behav 83:23-38. doi: 10.1016/j.yhbeh.2016.05.012

Summary: Oxytocin is well known for its hormonal role in lactation and parturition, but also exerts widespread actions in central nervous system. Previous experiments revealed the existence of a correlation between the changes in locomotor activity found in Oxytocin-SAP-treated rats and the extent of the changes in nigral TH and vesicular glutamate transporters immunoreactivity, provide support for a modulatory role of oxytocin on locomotor activity at the level of the substantia nigra. The day after a prior assessment of spontaneous locomotor activity, rats were randomly injected bilaterally with 0.3 μL of Oxytocin-SAP (Cat. #IT-46, 60 ng/μL/site), or with the same amount of Blank-SAP (Cat. #IT-21, 60 ng/μL/site) or with vehicle (0.3 μL/site of PBS, pH 7.4). Whether oxytocin may be considered as a target for controlling motor disturbances, as those occurring in Parkinson’s disease and/or in other motor disturbances related to basal ganglia dysfunctions, remains to be evaluated

Related Products: Oxytocin-SAP (Cat. #IT-46), Blank-SAP (Cat. #IT-21)

Mittelman-Smith M, Krajewski-Hall S, McMullen N, Rance N (2016) Ablation of KNDy neurons results in hypogonadotropic hypogonadism and amplifies the steroid-induced LH surge in female rats. Endocrinology 157:2015-2027. doi: 10.1210/en.2015-1740

Summary: KNDy neurons are a subpopulation of neurons in the infundibular nucleus that coexpress estrogen receptor α, kisspeptin, and neurokinin B (NKB) mRNA. Previous work indicated that altered signaling from KNDy neurons may play a role in the low levels of circulating sex steroids found in hypogonadotropic hypogonadism. Rats received bilateral 10-ng injections of NK3-SAP (Cat. #IT-63) dorsal to the arcuate nucleus. Blank-SAP (Cat. #IT-21) was used as control. In animals with intact ovaries the NK3-SAP lesion resulted in hypogonadotropic hypogonadism. In contrast, the LH surge in lesioned ovariectomized rats was 3-fold higher, demonstrating that KNDy neurons are integral for the control of serum LH levels, estrous cyclicity, and may also have some control over the magnitude of the LH surge.

Related Products: NKB-SAP (Cat. #IT-63), Blank-SAP (Cat. #IT-21)

Fu R, Chen X, Zuo W, Li J, Kang S, Zhou L, Siegel A, Bekker A, Ye J (2016) Ablation of μ opioid receptor-expressing GABA neurons in rostromedial tegmental nucleus increases ethanol consumption and regulates ethanol-related behaviors. Neuropharmacology 107:58-67. doi: 10.1016/j.neuropharm.2016.02.027

Summary: In this work the authors investigated cellular mechanisms underlying the aversive effects of alcohol that limit its intake. Previous work has linked synaptic inhibition of dopamine neurons in the ventral tegmental area to this aversion. Rats conditioned to ingest ethanol received bilateral injections totaling 3 pmol of Dermorphin-SAP (Cat. #IT-12) into the rostromedial tegemental nucleus (RTMg). Blank-SAP (Cat. #IT-21) was used as a control. Lesioned animals displayed significantly increased preference for, and intake of ethanol, while showing no change in the desire for sucrose. The results indicate that mu opioid expressing GABAergic neurons in the RTMg are highly involved in the regulation of ethanol consumption.

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

Li P, Janczewski W, Yackle K, Kam K, Pagliardini S, Krasnow M, Feldman J (2016) The peptidergic control circuit for sighing. Nature 530:293-297. doi: 10.1038/nature16964

Summary: Sighs are often associated with relief or sadness, but rodents sigh spontaneously dozens of times per hour. There are physiological benefits to sighing, including enhancement of gas exchange and preservation of lung integrity. The authors identify a peptidergic sigh control circuit in the retrotrapezoid nucleus/parafacial respiratory group of the mouse brain that projects to the pre-Bötzinger complex. Mice received bilateral 6.2-ng injections of Bombesin-SAP (Cat. #IT-40) into the pre-Bötzinger complex. Blank-SAP (Cat. #IT-21) was used as control. Elimination of the bombesin receptor-expressing neurons or inhibition of neuromedin B receptor-expressing neurons suppressed sighing. Interfering with the activity of both receptors abolished sigh activity while leaving normal breathing intact. The data suggest that overlapping peptidergic pathways are the core of a sigh control circuit.

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

Hulsey D, Hays S, Khodaparast N, Ruiz A, Das P, Rennaker R, Kilgard M (2016) Reorganization of motor cortex by vagus nerve stimulation requires cholinergic innervation. Brain Stimul 9:174-181. doi: 10.1016/j.brs.2015.12.007

Summary: Recent work has suggested that vagus nerve stimulation (VNS) can enhance neuroplasticity, and coupled with other training can drive motor cortex reorganization. These findings highlight the potential of VNS to support recovery from neurological disease. Pretrained rats received bilateral injections totaling 3.75 μg of 192-IgG-SAP (Cat. #IT-01) into the nucleus basalis (NB). Mouse-IgG-SAP (Cat. #IT-18) was used as control. Control animals displayed a substantial increase in proximal limb representation, lesion of the NB prevented this increase. Motor performance was similar between lesion and control groups, indicating that the difference in representation was not due to altered limb function.

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

Arora V, Morado-Urbina C, Aschenbrenner C, Hayashida K, Wang F, Martin T, Eisenach J, Peters C (2016) Disruption of spinal noradrenergic activation delays recovery of acute incision-induced hypersensitivity and increases spinal glial activation in the rat. J Pain 17:190-202. doi: 10.1016/j.jpain.2015.10.009

Summary: A significant percentage of patients who undergo surgery experience prolonged clinically impactful pain, reducing the quality of life and physical function. Disruption of the descending noradrenergic input has been hypothesized to be important to the generation of this type of pain state. Using an acute incision model, the authors administered 5 μg ofAnti-DBH-SAP (Cat. #IT-03) to the L5-L6 interspace of rats. Mouse IgG-SAP (Cat. #IT-18) was used as a control. Lesioned animals demonstrated a significant increase in mechanical hypersensitivity, and a smaller increase in thermal hypersensitivity. This and other results suggest that spinally projecting noradrenergic pathways are necessary for normal recovery from surgical incision, and possibly other types of pain.

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

Freiria-Oliveira A, Blanch G, Pedrino G, Cravo S, Murphy D, Menani J, Colombari D (2015) Catecholaminergic neurons in the comissural region of the nucleus of the solitary tract modulate hyperosmolality-induced responses. Am J Physiol Regul Integr Comp Physiol 309:R1082-1091. doi: 10.1152/ajpregu.00432.2014

Summary: Body fluid homeostasis and cardiovascular regulation are thought to be at least in part controlled by noradrenergic A2 neurons found in the nucleus of the solitary tract (NTS). In this work the authors investigated the involvement of A2 neurons of the commissural NTS in arterial pressure, as well as several body fluid homeostasis parameters. Rats received 12.6-ng injections of Anti-DBH-SAP (Cat. #IT-03) into the commissural NTS. Mouse IgG-SAP (Cat. #IT-18) was used as a control. Lesioned animals displayed increased c-Fos expression in the hypothalamic paraventricular nucleus when treated with hypertonic NaCl, and increased arterial pressure. The data indicate that commissural NTS A2 neurons are essential for inhibitory mechanisms that reduce water intake and pressor response to an acute increase in plasma osmolality.

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

Wiley RG (2015) Nociceptive effects of neurotensin(NTS)- and somatostatin(SST)-toxin conjugates applied to the lumbar dorsal horn in rats. Neuroscience 2015 Abstracts 418.11/O12. Society for Neuroscience, Chicago IL.

Summary: Intrathecal injections of NTS or SST have been reported to be anti-nociceptive, and in the case of SST, analgesic in humans. Preliminary experiments in our lab previously showed that lumbar intrathecal injection of the excitatory neuropeptide, NTS, or the inhibitory neuropeptide, SST, conjugated to the ribosome inactivating protein, saporin (sap), produced compulsive scratching/biting of hindquarters resulting in loss of fur and skin. This was thought likely due to pain and/or itching from selective loss of superficial dorsal horn nociceptive inhibitory interneurons expressing NTS receptors. Subsequent experiments using lumbar intrathecal injections of NTS-cholera toxin A chain conjugate resulted in prolonged anti-nociception on hotplate, tail flick and von Frey testing, that was not reversed by naloxone and lasted several days, likely due to sustained activation of the same neurons. The present study sought to determine if the lesions produced by NTS-sap or SST-sap alter nociceptive responses. In the present study, rats, under isoflurane anesthesia, were injected intrathecally using temporarily-placed subarachnoid catheters over the lumbar enlargement with 10 ul of sterile preservative-free normal saline containing either 300-400 ng of NTS-sap, 1 ug of SST-sap or 1 ug blank-sap (control) from Advanced Targeting Systems, San Diego, CA. Catheters were flushed with an additional 10 ul of saline. After post-surgical recovery, the rats were then observed for scratching/biting their hindquarters, nocifensive responses on the hotplate, von Frey mechanical probing of the hindpaws, and on operant thermal escape. 4 of 11 NTS-saporin rats and 5 of 9 SST-saporin rats, but none of 9 blank-saporin rats began scratching within 8-47 days after toxin conjugate injection. Hotplate nocifensive reflex testing at 44.5°C and 47°C showed no significant difference between the groups. Von Frey, operant thermal escape testing and anatomic studies are in progress to further specify the functional effects of the toxin conjugate injections and to identify the dorsal horn neurons being destroyed. The results to date are interpreted as consistent with a possibly unique role for NTS and/or SST receptor-expressing superficial dorsal horn inhibitory interneurons in nociception and/or itch. Excitatory/activating moieties such as cholera toxin A subunit targeted by conjugation to NTS or SST may offer a novel approach to enhance inhibition in nociceptive dorsal horn neurons and to produce analgesia by a non-opioid mechanism.

Related Products: Neurotensin-CTA (Cat. #IT-60), Neurotensin-SAP (Cat. #IT-56), Blank-SAP (Cat. #IT-21), Custom Conjugates

Zoccal DB, Taxini CL, Gargaglioni LH (2015) Control of sympathetic activity by A5 noradrenergic neurons in the in situ rat preparations. Neuroscience 2015 Abstracts 432.16/X11. Society for Neuroscience, Chicago IL.

Summary: The A5 area represents an important noradrenergic neuronal group located in the ventral pons that receives and sends projections to various medullary areas involved in the cardiorespiratory control. Its involvement in the chemoreflex control was previously studied in anesthetized conditions. In the present study, we explored the contribution of A5 noradrenergic neurons in the processing of sympathetic responses to central and peripheral chemoreceptors stimulation using the in situ working heart-brainstem rat preparation. Juvenile male Holztman rats received bilateral microinjections of either IgG-SAP (50nl, n=7) or toxin anti-dopamine beta-hydroxylase-saporin (anti-DβH-SAP, 4.2 ng/50 nl, n=6) in the A5. One week later, in situ preparations were obtained to record the thoracic sympathetic (tSN) and phrenic nerve (PN) activities; and stimulation of peripheral (KCN, 0.05%, 50nL) and central chemoreceptors (7 and 10% CO2 in the perfusate, 5 min) were performed. Baseline tSN activity (12.5±2.0 vs 12.6±2.4 μV), PN burst amplitude (40.7±9.7 vs 44.8 ±19.9 μV) and frequency (13±1 vs 15±2 bpm) and the respiratory-sympathetic coupling pattern were similar between control and A5-lesioned rats. The sympathetic ([[unable to display character: ∆]]tSN: 110±12 vs 58±8 %, P<0.05), but not the phrenic response to peripheral chemoreflex stimulation was marked attenuated in animals with lesion of A5 noradrenergic neurons. As to the central chemoreflex, the tSN response to 7% CO2 tSN: 9.5±1.4 vs 3.9±1.7%, P<0.05), but not to 10% CO2 (16.4±2.9 vs 10.9±1.6%) was lower in A5-lesioned rats in comparison to controls. On the other hand, the PN response to 7 and 10% CO2 were similar between control and A5-lesioned rats. Our data show that the A5 noradrenergic neurons are critical for the full expression of the sympathetic chemoreflex responses, possibly by providing an excitatory drive to the neurons generating sympathetic activity.

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