- Home
- Knowledge Base
- References
Featured Article: Basomedial hypothalamic injections of neuropeptide Y conjugated to saporin selectively disrupt hypothalamic controls of food intake
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:
Immunolesions of glucoresponsive projections to the arcuate nucleus alter glucoprivic-induced alterations in food intake, luteinizing hormone secretion, and GALP mRNA, but not sex behavior in adult male rats.
Fraley GS (2006) Immunolesions of glucoresponsive projections to the arcuate nucleus alter glucoprivic-induced alterations in food intake, luteinizing hormone secretion, and GALP mRNA, but not sex behavior in adult male rats. Neuroendocrinology 83(2):97-105. doi: 10.1159/000094375
Summary: In this work the author looked at the role hypothalamic glucose may play in reproductive function. 42 ng of anti-DBH-SAP (Cat. #IT-03) was injected dorsal of the arcuate nucleus of rats, which were then given glucoprivic challenges. Feeding and sex behavior were decreased during glucoprivation; sex behavior was also decreased in control animals. The data demonstrate the involvement of A1/C1 efferents to the ventromedial hypothalamus in glucostatic regulation of various processes.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Hypotensive hypovolemia and hypoglycemia activate different hindbrain catecholamine neurons with projections to the hypothalamus.
Dinh TT, Flynn FW, Ritter S (2006) Hypotensive hypovolemia and hypoglycemia activate different hindbrain catecholamine neurons with projections to the hypothalamus. Am J Physiol Regul Integr Comp Physiol 291(4):R870-R879. doi: 10.1152/ajpregu.00094.2006
Summary: Hypovolemia, a decrease in blood plasma volume, results in secretion of arginine vasopressin (AVP). This work investigates the role of hindbrain catecholamine neurons in hypovolemia-induced AVP secretion. Rats were treated with bilateral 42 ng injections of anti-DBH-SAP (Cat. #IT-03) into the paraventricular nucleus of the hypothalamus, and hypovolemia was induced by blood withdrawal. Treated animals displayed severely impaired AVP response, as well as lower food intake and corticosterone secretion in response to insulin.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Attenuation of homeostatic responses to hypotension and glucoprivation after destruction of catecholaminergic rostral ventrolateral medulla (RVLM) neurons.
Madden CJ, Stocker SD, Sved AF (2006) Attenuation of homeostatic responses to hypotension and glucoprivation after destruction of catecholaminergic rostral ventrolateral medulla (RVLM) neurons. Am J Physiol Regul Integr Comp Physiol 291(3):R751-R759. doi: 10.1152/ajpregu.00800.2005
Summary: C1 neurons in the RVLM express dopamine-beta-hydroxylase (DBH). Anti-DBH-SAP (Cat. #IT-03) was used to eliminate these neurons and examine cardiovascular homeostasis in response to a physiological challenge such as hypotension. 21 ng of anti-DBH-SAP was injected into the RVLM of rats. After food and water had been removed from the cage, the lesioned animals were treated with hydralazine to reduce blood pressure. The results demonstrate that RVLM-C1 cells are involved in responses to homeostatic challenges.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Differential responsiveness of dopamine-beta-hydroxylase gene expression to glucoprivation in different catecholamine cell groups.
Li AJ, Wang Q, Ritter S (2006) Differential responsiveness of dopamine-beta-hydroxylase gene expression to glucoprivation in different catecholamine cell groups. Endocrinology 147(7):3428-3434. doi: 10.1210/en.2006-0235
Summary: This work examines how subpopulations of hindbrain catecholaminergic neurons participate in systemic glucoregulation. Rats were treated with bilateral 42 ng infusions of anti-DBH-SAP (Cat. #IT-03) into the paraventricular nucleus of the hypothalamus. Dopamine-beta-hydroxylase (DBH) expression in glucoprivic animals was then analyzed by in situ hybridization and immunohistochemistry. The data demonstrate that the ventrolateral medulla contains most of the catecholamine neurons responsive to glucoprivation.
Related Products: Anti-DBH-SAP (Cat. #IT-03), Saporin (Cat. #PR-01)
Featured Article: Targeted toxins in pain
Wiley RG (2006) Featured Article: Targeted toxins in pain. Targeting Trends 7(2)
Related Products: 192-IgG-SAP (Cat. #IT-01), Anti-DBH-SAP (Cat. #IT-03), Anti-SERT-SAP (Cat. #IT-23), SP-SAP (Cat. #IT-07), SSP-SAP (Cat. #IT-11), Dermorphin-SAP / MOR-SAP (Cat. #IT-12),
Catecholamine neurones in rats modulate sleep, breathing, central chemoreception and breathing variability.
Li A, Nattie E (2006) Catecholamine neurones in rats modulate sleep, breathing, central chemoreception and breathing variability. J Physiol 570(Pt 2):385-396. doi: 10.1113/jphysiol.2005.099325
Summary: Brainstem catecholamine (CA) neurons are thought to modulate the processing of sensory information and participate in the control of breathing. Using a 5 µg injection of anti-DBH-SAP (Cat. #IT-03), or a control injection of mouse-IgG-SAP (Cat. #IT-18) into the fourth ventricle, the authors investigated breathing frequency and wakefulness. The results suggest that CA neurons promote wakefulness, participate in central respiratory chemoreception, stimulate breathing frequency, and minimize breathing variability during REM sleep.
Related Products: Anti-DBH-SAP (Cat. #IT-03), Mouse IgG-SAP (Cat. #IT-18)
Immunolesions of glucoresponsive projections to the arcuate nucleus alter glucoprivic feeding and luteinizing hormone secretion but not sex behavior in adult male rats
Fraley GS (2005) Immunolesions of glucoresponsive projections to the arcuate nucleus alter glucoprivic feeding and luteinizing hormone secretion but not sex behavior in adult male rats. Neuroscience 2005 Abstracts 758.7. Society for Neuroscience, Washington, DC.
Summary: Metabolic signals such as insulin, leptin and glucose are known to alter hypothalamic function. Although insulin and leptin are known to directly alter hypothalamic areas that regulate reproduction, the mechanisms by which glucose alters reproductive function are not as clear. Catecholaminergic neurons in the A1/C1 region of the hindbrain are glucose-responsive and project to the arcuate nucleus. To determine if this pathway is involved in the regulation of sex behavior and luteinizing hormone (LH) secretion, this catecholamingergic pathway was lesioned by injecting saporin conjugated to anti-dopamine-β-hydroxalase (DSAP) or unconjugated saporin (SAP) into the arcuate nucleus of adult male rats. Rats were given glucoprivic challenges then feeding and sex behaviors were observed. As was expected, the DSAP treated rats showed a significant decreased in feeding during glucoprivation (250 mg/kg 2-deoxy-D-glucose, 2DG) compared to SAP controls (p < 0.05). Glucoprivation caused a significant reduction in sex behavior (p < 0.05) in both SAP and DSAP animals equally, compared to saline treatments in either treatment group. At the end of the experiment, animals were given a final challenge with 2DG or saline, killed by decapitation and trunk blood was assayed for plasma LH levels. In SAP animals, 2DG elicited a significant decrease in plasma LH levels (p < 0.05). However, in DSAP animals there was a significant increase (p < 0.05) in plasma LH levels compared to saline-treated rats. These data indicate that the A1/C1 efferents to the ventromedial hypothalamus are involved in the glucostatic regulation of feeding behavior and LH secretion, but not sex behavior in the adult male rat.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Immunotoxic destruction of catecholaminergic pathways disrupts the onset of puberty in the female rat
Vander Schaaf EB, Lusk JD, Jarrard LE, I’Anson H (2005) Immunotoxic destruction of catecholaminergic pathways disrupts the onset of puberty in the female rat. Neuroscience 2005 Abstracts 406.10. Society for Neuroscience, Washington, DC.
Summary: Ascending catecholaminergic (NE/E) pathways from the brainstem terminate near gonadotropin releasing hormone cell bodies and terminals in the hypothalamus. To determine the significance of NE/E pathways in regulating puberty onset, a neurotoxin (dopamine-ß-hydroxylase conjugated to saporin, DSAP) was administered intracerebrally to developing female rats to destroy this pathway and the timing of puberty onset was monitored. DSAP or vehicle (unconjugated saporin, SAP) was injected into the hypothalamic paraventricular nucleus on Days 23-25 of age (n=10 per group). An additional 8 rats served as untreated controls. Growth rate was monitored daily and on surgery days SAP & DSAP rats grew at a slower rate than controls. Thus, food intake of control rats was temporarily adjusted to ensure that growth rate was similar between groups. Onset of puberty and cycle length were monitored via vaginal cytology. 2-Deoxy-D-glucose-induced glucoprivation determined which rats received complete DSAP lesions, since lesioned rats do not acutely increase food intake when glucose-deprived. Results showed that NE/E neurons were adequately lesioned in seven of ten DSAP rats. Puberty onset (time of first estrus) was delayed in DSAP-lesioned rats (40.86 ± 1.79 days of age, n=7) compared to vehicle or control rats (36.25 ± 0.31 days of age, n=10; 37.50 ± 0.31 days of age, n=8). Estrous cycle length of DSAP rats (5.38 ± 0.46 days, n=7) was not significantly longer than in vehicle or control rats (4.91 ± 0.18 days, n=10; 4.40 ± 0.12 days, n=8). Thus, lesioning the NE/E pathway caused delay in onset of puberty in female rats, but no significant change in estrous cycle length. Therefore, ascending catecholaminergic pathways from the brainstem are important in determining puberty onset timing. First estrus did eventually occur in DSAP rats, suggesting that other neural pathways may be activated to regulate puberty onset and estrous cyclicity in its absence.
Related Products: Anti-DBH-SAP (Cat. #IT-03)
Experimental dissociation of neural circuits underlying anorexic and conditioned avoidance responses to LiCl in rats
Rinaman L, Maldovan V (2005) Experimental dissociation of neural circuits underlying anorexic and conditioned avoidance responses to LiCl in rats. Neuroscience 2005 Abstracts 529.7. Society for Neuroscience, Washington, DC.
Summary: The central nucleus of the amygdala (CeA) receives viscerosensory input from noradrenergic (NA) neurons in the nucleus of the solitary tract (NST) and from peptidergic non-NA neurons in the lateral parabrachial nucleus (laPBN). A previous study (J. Neurosci. 23:10084-92) demonstrated that NA neurons in the caudal NST are necessary for cholecystokinin (CCK) to inhibit food intake in rats, but are unnecessary for CCK to activate Fos expression in the laPBN and CeA. The laPBN and CeA are integral components of central neural circuits that underlie the formation and expression of conditioned flavor avoidance (CFA). Thus, the neural substrates for treatment-induced anorexia may be separable from those for CFA. To test this idea, saporin toxin conjugated to an antibody against dopamine β hydroxylase was microinjected bilaterally into the caudal NST in adult male rats in order to selectively lesion NA neurons. Three weeks later, lesioned and sham control rats were tested for the ability of 0.15M LiCl (2% BW, i.p.) to inhibit food intake and to support conditioned flavor avoidance (CFA). Anorexia after LiCl was significantly blunted in lesioned rats compared to sham controls, similar to our previous findings in lesioned rats after CCK treatment. However, LiCl still supported robust CFA in lesioned rats, and its magnitude was similar to that seen in sham controls. A terminal Fos study revealed intact LiCl-induced activation of neural Fos expression in the laPBN and CeA in lesioned rats, despite significant loss of NA neurons in the caudal NST. These new findings support the view that NA neurons in the caudal NST are unnecessary for laPBN and CeA neural responses to viscerosensory stimulation, and also are unnecessary for the learning and expression of conditioned flavor avoidance.
Related Products: Anti-DBH-SAP (Cat. #IT-03)