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Transneuronal tracing from sympathectomized lumbar epaxial muscle in female rats.
Daniels D, Miselis RR, Flanagan-Cato LM (2001) Transneuronal tracing from sympathectomized lumbar epaxial muscle in female rats. J Neurobiol 48(4):278-290. doi: 10.1002/neu.1057
Summary: The authors use pseudorabies virus (PRV) to study central neural networks such as the one controlling the lordosis reflex (increased curvature of the spine). To aid in the separation of the sympathetic nervous system and higher order systems, rats were treated with lumbar injections of anti-DBH-SAP (156 ng to 5 µg; Cat. #IT-03), then labeled with PRV. PRV labeling in the brain was absent in areas associated with vasomotor tone, but persisted in areas implicated in control of the lordosis response.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
It’s enough to raise your blood pressure!
Deuchars J, Deuchars S (2001) It’s enough to raise your blood pressure!. Trends Neurosci 24(4):200. doi: 10.1016/s0166-2236(00)01800-2
Summary: The authors review studies completed by Schreihofer and Guyenet using anti-DBH-SAP (Cat. #IT-03) to eliminate C1 adrenergic neurons. The results show that, although C1 neurons play a role in some sympathoexcitatory responses, they are probably not responsible for maintaining sympathetic tone.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Immunotoxic destruction of distinct catecholamine subgroups produces selective impairment of glucoregulatory responses and neuronal activation.
Ritter S, Bugarith K, Dinh TT (2001) Immunotoxic destruction of distinct catecholamine subgroups produces selective impairment of glucoregulatory responses and neuronal activation. J Comp Neurol 432(2):197-216. doi: 10.1002/cne.1097
Summary: Control of regulatory responses to low glucose levels in the brain have been linked to catecholaminergic neurons. Studies of these neurons have been hindered by the lack of a selective and precise lesioning agent. Ritter et al. use anti-DBH-SAP (Cat. #IT-03) to create very precise lesions of catecholamine neurons in the paraventricular nucleus of the hypothalamus and spinal cord. Injection of anti-DBH-SAP into the spinal cord eliminates cells with caudal projections while injection into the paraventricular nucleus of the hypothalamus eliminated cells with rostral projections. This ability to selectively eliminate very specific subpopulations of cells is a valuable characteristic in dissecting neuronal function.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Featured Article: Immunolesioning: From spinal cord to brain
Schreihofer A (2001) Featured Article: Immunolesioning: From spinal cord to brain. Targeting Trends 2(1)
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Read the featured article in Targeting Trends.
See Also:
- Schreihofer AM et al. Sympathetic reflexes after depletion of bulbospinal catecholaminergic neurons with anti-DBH-saporin. Am J Physiol Regul Integr Comp Physiol 279:R729-R742, 2000.
- Schreihofer AM et al. Role of presympathetic C1 neurons in the sympatholytic and hypotensive effects of clonidine in rats. Am J Physiol Regul Integr Comp Physiol 279:R1753-R1762, 2000.
- Schreihofer AM et al. Regulation of sympathetic tone and arterial pressure by rostral ventrolateral medulla after depletion of C1 cells in rat. J Physiol 529(1):221-236, 2000.
Antinociceptive action of nitrous oxide is mediated by stimulation of noradrenergic neurons in the brainstem and activation of a2B adrenoceptors.
Sawamura S, Kingery WS, Davies MF, Agashe GS, Clark JD, Kobilka BK, Hashimoto T, Maze M (2000) Antinociceptive action of nitrous oxide is mediated by stimulation of noradrenergic neurons in the brainstem and activation of a2B adrenoceptors. J Neurosci 20(24):9242-9251. doi: 10.1523/JNEUROSCI.20-24-09242.2000
Summary: Nitrous oxide has been used extensively in surgical anesthesia for more than 150 years, but the molecular mechanism of action has not yet been defined. Sawamura et al. investigate whether noradrenergic neurons in the brainstem are involved in the analgesic action of nitrous oxide. The authors injected rats with anti-DBH-SAP (Cat. #IT-03) to destroy pontine noradrenergic neurons. The treated rats demonstrated the usual sedative effects of nitrous oxide, but the analgesic effects were reduced or blocked. Coupled with data from null mice for the alpha2B adrenoceptor, the data indicates that alpha2 adrenoceptor subtypes and ligands are involved in the analgesic but not sedative effects of nitrous oxide.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Neuronal lesioning with axonally transported toxins.
Wiley RG, Kline IV RH (2000) Neuronal lesioning with axonally transported toxins. J Neurosci Methods 103:73-82. doi: 10.1016/S0165-0270(00)00297-1
Summary: Functional neuroanatomy studies have long utilized lesioning. Given the complexity of heterogeneous neuron populations conventional lesioning methods have proved relatively crude, and have provided limited information. Wiley and Kline detail some of the immunotoxins utilizing saporin as well as neuropeptide-saporin conjugates that have found use in recent neurological research. These products include SP-SAP (Cat. #IT-07), which eliminates neurons expressing the neurokinin 1 receptor, 192-Saporin (Cat. #IT-01), which eliminates neurons expressing the p75 receptor in rats, anti-DBH-SAP (Cat #IT-03), which destroys noradrenergic and adrenergic neurons, and OX7-SAP (Cat. #IT-02), which is a suicide transport agent targeting all rat neurons. The authors also discuss some of the protocols and methods utilized with these compounds.
Related Products: 192-IgG-SAP (Cat. #IT-01), OX7-SAP (Cat. #IT-02), Anti-DBH-SAP (Cat. #IT-03), SP-SAP (Cat. #IT-07)
Intracortical injection of DBH-saporin targets noradrenergic axons in the medial prefrontal cortex of the rat.
Mazei MS, Wiley RG, Deutch AY (2000) Intracortical injection of DBH-saporin targets noradrenergic axons in the medial prefrontal cortex of the rat. Neuroscience 2000 Abstracts 639.8. Society for Neuroscience, New Orleans, LA.
Summary: The medial prefrontal cortex (mPFC) is innervated by both dopaminergic and noradrenergic neurons. While the densities of the two types of catecholamine axons are different in subregions of the mPFC, axons of both types are present in most of the mPFC. The goal of this study was to selectively lesion noradrenergic axons in the rat mPFC while sparing dopaminergic axons, using microinjection of the immunotoxin dopamine β-hydroxylase (DBH)-saporin. DBH-saporin (10- 100 ng/μ1) was unilaterally injected into three brain regions, the mPFC, caudate-putamen (CP) and cerebellum. Rats were sacrificed 2-10 days post-injection and the lesion was characterized by tyrosine hydroxylase (TH), DBH, and norepinepherine transporter (NET) immunohistochemistry. DBH-saporin administration resulted in discrete lesions. There appeared to be a decrease in the number of immunoreactive (ir) axons after DGH-saporin infusion into the mPFC: surviving axons were swollen and dystrophic. However, the effect of DBH-saporin appears more pronounced when examining DBH-ir than with NET-ir. Intrastriatal injections of DBH-saporin did not decrease TH-ir, suggesting that dopaminergic axons were spared. Since DBH-saporin acts by entry into DBH-containing vesicles, a longer time course may be necessary to observe loss of the NET marker than DBH. Studies are in progress to examine this possibility.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
DBH-saporin lesions the locus coeruleus, but does not produce cataplexy or abnormal REM sleep triggering.
Blanco-Centurion CA, Salin-Pascual R, Gerashchenko D, Greco MA, Lappi DA, Kilduff TS, Shiromani PJ (2000) DBH-saporin lesions the locus coeruleus, but does not produce cataplexy or abnormal REM sleep triggering. Neuroscience 2000 Abstracts 566.17. Society for Neuroscience, New Orleans, LA.
Summary: Recently, canine narcolepsy was associated with a mutation in the hypocretin-2 receptor (Lin et al., 1999), which binds the neuropeptide hypocretin, also known as orexin. The locus coeruleus receives a very heavy projection of HCRT/OX fibers, and the LC also contains HCRT/OX receptor mRNA. Silence of LC neurons is hypothesized to be key in triggering cataplexy and REM sleep. To test this hypothesis, DBH-saporin was used to selectively lesion the LC. Male Sprague-Dawley rats (400-450 g) instrumented for recording sleep were given DBH-saporin (n=4) (500ng/0.5ul) via a micropipette to the LC. Control rats were administered 192-saporin (n=3), or saline (n=4). Two days later, sleep recordings were obtained for 7 consecutive days. The rat’s behavior was videotaped at night. To identify whether cataplexy was induced, the alpha antagonist, Prazosin was administered (1500h, 500mg/kg, IP) and then sleep and video recordings were made for three hours. Brains were removed for histology. DBH-saporin completely lesioned the LC neurons. However, there were no changes in wakefulness, nonREM or REM sleep. Video recordings also did not reveal any cataplexy episodes. The application of Prazosin did not induce cataplexy or diminish muscle tone in DBH-saporin LC treated rats. Historically, LC lesions have never been found to induce cataplexy. Use of DBH-saporin provides a more specific lesion restricted to the LC neurons where the HCRT/OX receptor mRNA is localized. Our findings indicate that LC neurons are not essential for maintaining muscle tone or wakefulness.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Anti-dβh-saporin injection into the paraventricular nucleus of the hypothalamus selectively abolishes 2DG-induced feeding without causing nonspecific tissue destruction.
Ritter S, Dinh TT, Bugarith K (2000) Anti-dβh-saporin injection into the paraventricular nucleus of the hypothalamus selectively abolishes 2DG-induced feeding without causing nonspecific tissue destruction. Neuroscience 2000 Abstracts 502.8. Society for Neuroscience, New Orleans, LA.
Summary: The toxin-antibody complex, saporin conjugated to a monoclonal antibody against dopamine-β-hydroxylase (anti-dβh-sap), selectively destroys dβh-containing catecholamine neurons. Previously we reported that PVH anti-dβh-sap injections abolish feeding and expression of Fos-immunoreactivity (-ir) in the PVH in response to 2DG-induced glucoprivation and cause selective destruction of dβh-containing neurons innervating the hypothalamus. To test the behavioral and neurochemical specificity of this lesion, anti-dβh-sap or control solution (saline or unconjugated saporin) was injected bilaterally into the PVH (n=6 per group). Beginning three weeks later, rats were tested for stimulation of feeding by 2-deoxy-D-glucose (2DG, 200 mg/kg) and mercaptoacetate (MA, 68 mg/kg), which reduce glucose and fatty acid oxidation, respectively, and for suppression of feeding by cholecystokinin octapeptide (CCK, 4 ug/kg). 2DG-induced feeding was abolished by anti-dβh-sap injection, but was not impaired by unconjugated saporin. Neither MA nor CCK responses were altered by anti-dβh-sap. The nonspecific toxicity of anti-dβh-sap at the injection site was assessed. We found that PVH magnocellular neurons at the injection site express oxytocin-ir and do not appear to be disrupted by the anti-βh-sap injection. Further, the ability of PVH neurons at the injection site to express Fos in response to a non-glucoprivic stimulus was not impaired by anti-dβh-sap since lateral ventricular injection of senktide, an NK3 receptor agonist, induced Fos ir in the PVH. PVH injections of anti-dβh-sap impair 2DG-induced feeding and PVH Fos expression by selective destruction of catecholamine neurons. PHS#DK 40498.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Distribution of mu-opioid receptors and activated G-proteins in rat cingulate cortex and alterations following removal of noradrenergic afferents.
Vogt LJ, Sim-Selley LJ, Childers SR, Wiley RG, Vogt BA (2000) Distribution of mu-opioid receptors and activated G-proteins in rat cingulate cortex and alterations following removal of noradrenergic afferents. Neuroscience 2000 Abstracts 238.1. Society for Neuroscience, New Orleans, LA.
Summary: Anterior cingulate cortex (ACC) is involved in acute and chronic pain processing. Here we define opioid architecture throughout rat cingulate cortex, relate mu-opioid receptor and G-protein stimulated binding in particular layers, and localize binding to noradrenergic terminals with immunotoxin lesions (anti-DBH-saporin). [3H]DAMGO binding was highest in areas 32 and 24 with a peak in layer I. Midcingulate area 24′ and posterior area 29 had lower and homogeneous binding. DAMGO stimulated [35S]GTPγS binding in area 24′ was similar to that in areas 32 and 24, while area 29 had very low and homogeneous binding. Undercut lesions reduced [3H]DAMGO binding in all layers with greatest loss in layer I, while DAMGO-stimulated [35S]GTPγS binding losses occurred only in layers I-III. Since neurons in the midline thalamic nuclei and locus coeruleus synthesize mu-opioid receptors, noradrenergic afferents were removed with anti-DBH-saporin. This toxin reduced [3H]DAMGO binding only in layer I of areas 32 and 24, while DAMGO-stimulated [35S]GTPγS binding increased in layer II of areas 32 and 24, had no changes in area 24′, and decreased binding in layer I of area 29. Thus, in addition to their actions on ACC neurons, other sites of opiate drug actions are through mu-opioid heteroreceptors on glutamatergic thalamic and noradrenergic locus coeruleus afferents to ACC.
Related Products: Anti-DBH-SAP (Cat. #IT-03)