References

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)

Bourane S, Duan B, Koch S, Dalet A, Britz O, Garcia-Campmany L, Kim E, Cheng L, Ghosh A, Ma Q, Goulding M (2015) Gate control of mechanical itch by a subpopulation of spinal cord interneurons. Science 350:550-554. doi: 10.1126/science.aac8653

Summary: Light mechanical stimulation of the hairy skin can induce a form of itch known as mechanical itch. This itch sensation is normally suppressed by inputs from mechanoreceptors, however, in many forms of chronic itch, including alloknesis, this gating mechanism is lost. Scientists demonstrated that a population of spinal inhibitory interneurons (INs), that are defined by the expression of neuropeptide Y::Cre (NPY::Cre), act to gate mechanical itch. Mice in which dorsal NPY::Cre-derived neurons are selectively ablated or silenced develop mechanical itch without an increase in sensitivity to chemical itch or pain. This chronic itch state is histamine-independent and is transmitted independently of the GRP-GRPR signaling pathway. The scientists thereby revealed a dedicated spinal cord inhibitory pathway that gates the transmission of mechanical itch. Mice were given an intrathecal injection of 400 ng of Bombesin-SAP (Cat. #IT-40) in 10 ml of sterile saline to ablate GRPR-expressing neurons.

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

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)

Kiley BJ, Sengelaub DR (2015) Neuroprotection with androgens following partial motoneuron depletion: A role for microglia. Neuroscience 2015 Abstracts 689.18/K11. Society for Neuroscience, Chicago IL.

Summary: Neurodegenerative disease or nerve injury results in the loss of spinal motoneurons, and remaining motoneurons show a variety of morphological and functional changes. We have previously demonstrated that partial depletion of motoneurons innervating the quadriceps muscles induces dendritic atrophy in remaining motoneurons, with 70% decreases in dendritic length. Treatment with testosterone is neuroprotective, and dendritic atrophy following partial motoneuron depletion is attenuated. In the present study, we explored a potential mechanism for this induced atrophy and the protection by androgen treatment, examining the response of microglia to the partial depletion of motoneurons with and without testosterone treatment. Microglia are activated locally and recruited from other sites in response to injury. Microglia are involved in the removal of synapses and dendrites after injury, and there is evidence that their activation is influenced by steroid hormones. Motoneurons innervating the vastus medialis muscle in adult male rats were selectively killed by intramuscular injection of cholera toxin-conjugated saporin. Simultaneously, saporin-injected rats were given systemic treatments via interscapular implants containing testosterone or left blank. One or three weeks later, microglia were visualized after immunohistochemical staining for Iba1. Microglia surrounding the injured motoneurons were classified as monitoring or activated (primed, reactive, or ameboid) based on morphology and counted stereologically. Compared with intact males, partial motoneuron depletion resulted in increases in the total number of microglia (78% and 24% at 1 and 3 weeks post-saporin, respectively) in the quadriceps motor pool. These changes were driven by increases in the number of activated microglia compared to levels found in intact animals; the number of activated microglia increased by 144% at 1 week post-saporin, and remained elevated at 3 weeks (51%). The increases in the number of activated microglia were attenuated with testosterone treatment; the number of activated forms increased only 34% and 17% at 1 and 3 weeks post-saporin, respectively. These findings suggest that the dendritic atrophy observed in remaining motoneurons after partial motoneuron depletion could be a result of increased microglial activation in the injury site, resulting in collateral damage through synaptic stripping and dendritic loss. The attenuation of both dendritic atrophy and microglial activation with testosterone treatment supports this potential causal effect, and further supports a role for hormones as neurotherapeutic agents in the injured nervous system.

Related Products: CTB-SAP (Cat. #IT-14)

Palomares E, Hernandez Perez O, Crespo Ramirez M, Aguilar Roblero R, Fuxe K, Perez de la Mora M (2015) Selective ablation of the intercalated neurons of the amygdala increased the anxiety-like behavior in the Elevated Plus Maze. Neuroscience 2015 Abstracts 694.14/N4. Society for Neuroscience, Chicago IL.

Summary: The intercalated (ITC) islands of the amygdala are clusters of inhibitory neurons that surround the basolateral complex (BLA) and contain a dense population of dopamine D1 and μ-opioid receptors. Lateral ITC (lITC) islands provide feed-forward inhibition to the BLA, whereas medial ITC (mITC) islands form an inhibitory interface between the BLA and central nucleus (CeA), the main output region of the amygdala. Previous studies have shown that ITC neurons play a role in fear extinction. However the functional role of the ITC islands in the un-conditioned anxiety has not been studied. To elucidate the involvement of the ITC islands in the anxiety-like behavior in the Elevated Plus Maze, we bilaterally infused the toxin saporin conjugate with the agonist of the μ-opioid receptors, dermorphine, (SAP-DER; 0.75pmol/0.250µl/lado) in closed proximity to the mITC islands to specifically ablate the neurons of the ITC islands. Behaviorally, SAP-DER injections significantly increased the time that the rats spent in the open arm of the maze as compared with their lesion control group. No effects on locomotion in the open-field test were found. These results suggest that ablate of the ITC neurons results in anxiogenic effects and support ITC neurons play an important role in mediate anxiolytic responses.

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

Nam H, Kerman I (2015) A2 noradrenergic neurons regulate forced swim test immobility. Neuroscience 2015 Abstracts 718.10/Y20. Society for Neuroscience, Chicago IL.

Summary: The Wistar-Kyoto rat (WKY) is a well-established animal model of depression- and anxiety-like behavior, characterized by high immobility during the forced swim test (FST) along with a generally inhibited phenotype on related tests of emotional behaviors. Extensive literature indicates that deficits in noradrenergic neurotransmission may contribute to these behavioral traits. Previously, we have reported that the WKY rats are more immobile compared to other rat strains from the beginning of their training phase of the FST, and that they become even more immobile during the testing phase on the next day. We hypothesized that higher immobility during the FST and the greater increase in immobility throughout different phases of the FST are two separate components of rats’ behavior likely mediated by different central mechanisms. We sought to identify the central circuits responsible for these behavioral components by studying activation of neurons within central noradrenergic cell groups during different phases of the FST. The WKY rats along with its parent strain, Wistar rats that experienced either the: 1) 5 minutes training phase (D1), or 2) entire FST (D1 and D2) were compared. Using double-immunocytochemistry for tyrosine hydroxylase and for c-Fos, we determined that within the A2 cell group significantly more noradrenergic neurons were activated in the Wistar than in WKY rats at D1. At D2 WKYs increased their activation of the A2 noradrenergic neurons, and this activation was equivalent to that of the Wistar group. Based on these results, we further investigated the role of A2 cell group during the FST using anti-DBH conjugated saporin (DSAP) to selectively destroy noradrenergic neurons within the area. The Wistar rats treated with DSAP were more immobile during both D1 and D2 of the FST as compared to the rats treated with the vehicle only. Together these data indicate that the A2 noradrenergic cell group regulates FST immobility in rats, and that its activation may contribute to the unique behavioral phenotype of WKY rats. Future experiments aimed at selective activation of A2 noradrenergic neurons will be required to fully elucidate the role of these neurons in mediating behavioral despair and learned helplessness.

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

Horner KA, Logan M, Murray RC (2015) Ablation of the patch compartment reduces cocaine-induced stereotypy. Neuroscience 2015 Abstracts 506.23/M12. Society for Neuroscience, Chicago IL.

Summary: Repeated exposure to cocaine (COC) induces stereotypy, which is characterized as inflexible, repetitive behavior. Enhanced relative activation of the patch compartment of the striatum has been shown to positively correlate with the emergence of stereotypy following repeated COC treatment, suggesting that stereotypy may be related to preferential activation of this region. However, the specific contribution of the patch compartment to COC-induced stereotypy following repeated exposure is unknown. To elucidate the involvement of the patch compartment to the development of stereotypy in response to repeated COC exposure, we determined if destruction of this sub-region altered COC-induced behaviors. Animals were bilaterally infused in the striatum with the neurotoxin dermorphin-saporin (DERM-SAP; 17 ng/[[Unsupported Character – Symbol Font ]]l) to ablate the neurons of the patch compartment and allowed to recover for eight days. The animals were given daily injections of COC (25 mg/kg) or saline for one week, followed by a weeklong drug-free period. Animals were then given a challenge dose of COC, placed in activity chambers, observed for 2h and sacrificed. DERM-SAP pretreatment reduced the number of mu-labeled patches in the striatum. DERM-SAP pretreatment significantly reduced the intensity and spatial immobility of COC-induced stereotypy. In support of this observation, increased locomotor activity was seen in DERM-SAP pretreated, COC-treated animals. DERM-SAP pretreatment attenuated COC-induced c-Fos expression in the patch compartment, while enhancing COC-induced c-Fos expression in the matrix compartment. These data indicate that the patch compartment is necessary for repetitive behavior and suggests that alterations in activity in the patch vs matrix compartments may contribute to this phenomenon.

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

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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)