References

Fogo G, Gall AJ (2017) Behavioral effects following ablation of retinal ganglion cells in diurnal grass rats. Neuroscience 2017 Abstracts 237.03 / HH34. Society for Neuroscience, Washington, DC.

Summary: Light influences behavior and physiology in mammals by entraining circadian rhythms and also through direct and acute inhibition or stimulation of activity, a process called masking. Although there has been substantial progress elucidating the mechanisms responsible for the workings of the circadian system in nocturnal species, less is known about the mechanisms that support the diurnal profile of activity of mammals, especially as they relate to the retina. We recently showed that the intergeniculate leaflet (IGL) is critical for the display of normal patterns of daily activity in diurnal grass rats (Arvicanthis niloticus). Specifically, IGL lesions reverse the activity patterns of these animals such that they became night-active; this occurred through their effects on both circadian mechanisms and masking. The IGL is a thalamic structure that receives direct inputs from the melanopsin containing intrinsically photosensitive retinal ganglion cells, known as ipRGCs. Our current approach takes advantage of a diurnal mammalian model, the Nile grass rat, to test the novel hypothesis that melanopsin is critical for the expression of diurnal behavior and physiology, and is involved in masking responses to light. We will achieve this goal by injecting the immunotoxin anti-melanopsin-saporin intraocularly in grass rats and examining behavior following this experimental manipulation. Animals will be placed in various lighting conditions, including 12:12 light-dark conditions, and will be given pulses of light to test for effects of masking. We predict that controls will exhibit more general activity during the day, consistent with a diurnal species, and will exhibit increased activity following acute pulses of light. We predict that animals with the melanopsin toxin in the retina will be out of phase with controls in behavior following acute pulses of light, similar to animals with IGL lesions. Altogether, we are building a model to understand the mechanisms underlying the normal display of diurnal behavior, and we hope to add to this knowledge by examining how melanopsin contributes to the display of diurnal behavior in grass rats.

Related Products: Melanopsin-SAP (Cat. #IT-44)

Sharma A, Sharma R, Mackey C, Sahota P, Thakkar M (2017) Basal forebrain cholinergic neurons are vital for cortical desynchronization and behavioral arousal observed after nicotine consumption. Neuroscience 2017 Abstracts 241.1 / LL2. Society for Neuroscience, Washington, DC.

Summary: Purpose: Nicotine is an addictive constituent of tobacco which severely affects behavior. Sleep disruptions including reducing total sleep time, increasing sleep fragmentation and reducing sleep efficiency are very common in nicotine users. However, the underlying neuronal mechanism of how nicotine promotes desynchronization and disrupts sleep is unknown. We have shown that the basal forebrain (BF) is a key brain region, mediating nicotine’s effects on sleep-wakefulness (SFN 2015; Poster#166). The BF contains multiple neuronal phenotypes including cholinergic, GABAergic and glutamatergic subtypes. Thus, this study was designed to examine the neuronal subtype responsible for nicotine effects on sleep-wakefulness. As a first step, we focused on BF cholinergic neurons because BF cholinergic neurons are wake-promoting, express nicotinic receptors and supply acetylcholine to the prefrontal cortex, hippocampus and amygdala. We hypothesized that lesions of BF cholinergic neurons will attenuate nicotine induced cortical arousal/desynchronization. Methods: To test our hypothesis, adult male Sprague-Dawley rats were implanted with sleep recording electrodes and were divided into two groups: Lesion: Selective lesion of the BF cholinergic neurons was performed by bilateral administration of immunotoxin, 192-IgG-Saporin (SAP; 0.28 µg/0.5µL/side) in the BF; Sham (controls): Rats were bilaterally infused with saline (0.5µL/side). After injections, animals were left undisturbed for 3 weeks. Day 1: saline was administered subcutaneously at light/sleep onset. Day 2: Nicotine (0.3 mg/Kg) was administered at the same time. Sleep- wakefulness was examined for next 6 hours. On completion, animals were euthanized and the brains were processed for choline acetyltransferase (ChAT) immunohistochemistry to verify BF cholinergic lesions. Results: Our preliminary results: As compared to controls, lesioned rats, with a 64% reduction in cholinergic neurons, displayed attenuated nicotine induced cortical desynchronization and behavioral arousal. Conclusions: Our results suggest that the BF cholinergic neurons mediate nicotine induced cortical arousal/desynchronization that may be the cause of sleep disruptions in nicotine users.

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

Bowrey HE, James MH, Mohammadkhani A, Omrani M, Kane G, Aston-Jones G (2017) Chemogenetic activation of a retinal circuit that activates locus coeruleus neurons prevents the development of light- deprivation induced depression-like behavior. Neuroscience 2017 Abstracts 244.02 / NN6. Society for Neuroscience, Washington, DC.

Summary: Introduction: Chronic light-deprivation induces a depressive-like phenotype via a locus coeruleus norepinephrine (LC-NE)- dependent mechanism (Gonzalez and Aston-Jones, 2008). Suprachiasmatic nucleus (SCN) provides indirect circadian input onto LC via dorsomedial hypothalamus (DMH) (Aston-Jones et al 2001). SCN is therefore in a key position to integrate light information with LC via the pathway: retina→SCN→DMH→LC. We refer to this pathway as the Photic Regulation of Arousal and Mood (PRAM) pathway. We tested the hypothesis that increasing PRAM pathway activity prevents darkness-induced depression-like behavior. Methods: Expt 1. Sprague Dawley rats received intraocular injections of excitatory hM3Dq DREADD (AAV2-hSyn-hM3D(Gq)- mCherry) control virus (AAV2-hSyn-EGFP) or no virus. Rats were placed in continuous darkness for 8 weeks, and those that received virus were concurrently subjected to daily intraperitoneal injections of clozapine-N-oxide (CNO; 2 mg/kg), the DREADD-activating ligand. Rats were then subjected to assays of mood (saccharin preference test, elevated plus maze and forced swim test) or vision (electroretinagram: ERG). LC tissue was stained for Poly ADP ribose polymerase (PARP, a marker of apoptosis) and tyrosine hydroxilase (TH). Expt 2. To determine the retinal cell-type responsible for depression-like behavior, intrinsically photosensitive retinal ganglion cells (ipRGCs) of animals raised in 12:12 light:dark conditions were ablated using a saporin (SAP) toxin that selectively eliminates melanopsin-expressing cells (Mel-SAP). Two control groups received intraocular injections of vehicle and were kept in either continuous darkness or in 12:12 light:dark conditions. Ten weeks later, rats were subjected to identical analyses as those in Expt 1. Results: Expt 1. ERG analysis showed that CNO-activation of retinal DREADDs increased RGC activity. Constant darkness induced a depression-like phenotype in control animals, which was prevented by daily activation of retinal DREADDs by CNO. Expt 2. Mel-SAP induced a depression-like phenotype in animals maintained in normal light-dark conditions. This was also associated with increased apoptosis in LC-NE cells as seen with PARP staining. Conclusion: Dysregulation of the PRAM pathway may induce neural damage in LC-NE neurons that is associated with a depressive behavioral phenotype. DREADD-induced activation of RGCs can prevent depression-like behaviors that normally occur in rats kept in chronic darkness. The PRAM pathway presents a novel circuit for the regulation of mood, and thus a possible new direction for the treatment of some forms of depression in humans.

Related Products: Melanopsin-SAP (Cat. #IT-44)

Barnett WH, Molkov YI, Lemes E, Falqueto B, Colombari E, Takakura AT, Moreira TS, Zoccal DB (2017) Local glutamatergic transmission in the RTN/pFRG is critical for active expiration and sympathetic overactivity during hypercapnia. Neuroscience 2017 Abstracts 233.1 / FF22. Society for Neuroscience, Washington, DC.

Summary: The retrotrapezoid nucleus (RTN) contains chemosensitive cells that distribute CO -dependent excitatory drive to the brainstem respiratory network. This drive facilitates the function of the respiratory central pattern generator (CPG), modulates sympathetic activity and determines the emergence of active expiration during hypercapnia via activation of the late expiratory (late-E) oscillator in the parafacial respiratory group (pFRG). However, the microcircuitry responsible for distribution of the chemoreflex signal to the pFRG and the respiratory CPG is not well understood. Previously, we developed a computational model of the brainstem respiratory network, which was subsequently extended to include the central and peripheral chemoreflexes as well as presympathetic circuits. We present here experiments performed on the decerebrated, arterially-perfused in situ rat, aimed to test a key assumption of this model that chemosensitive and late-E neurons in the RTN/pFRG are two distinct populations, and the latter receives local glutamatergic input from the former. The model predicts: (1) suppression of RTN chemosensitive neurons will diminish the changes to the respiratory pattern and the emergence of active expiration associated with hypercapnia; (2) the disruption of local glutamatergic neurotransmission in the RTN will specifically suppress active expiration and the appearance of late-E discharges in the sympathetic motor output. To test prediction (1) we lesioned NK1 -positive chemosensitive neurons of the RTN with microinjections of substance P-saporin (SSP-SAP) conjugate. This suppressed the emergence of late-E activity in abdominal (AbN) and sympathetic nerves, and attenuated the increase in phrenic burst amplitude during hypercapnia. However, SSP-SAP and control animals exhibited late-E AbN activity in response to peripheral chemoreflex activation. Prediction (2) was tested with bilateral microinjections of kynurenic acid (Kyn, 100 mM) in the RTN/pFRG, which suppressed the emergence of late-E AbN activity but not the change in phrenic nerve amplitude during hypercapnia. Our results support the notion that RTN chemosensitive neurons are critical for inspiratory and expiratory reflex responses to hypercapnia. Our findings indicate that activation of late-E neurons in the pFRG during hypercapnia requires glutamatergic inputs from a separate neuronal population in the RTN that intrinsically detects changes in CO . During peripheral chemoreflex stimulation, pFRG late-E neurons are activated via excitatory pathways bypassing the RTN central chemoreceptors. We recapitulate these results in our computational model.

Related Products: SSP-SAP (Cat. #IT-11)

Larin AA, Karpova SA, McCarley RW, Basheer R, Kalinchuk AV (2017) Glutamate and adenosine, basal forebrain and cortex: Cross-talk during prolonged wakefulness. Neuroscience 2017 Abstracts 72.2 /KK24. Society for Neuroscience, Washington, DC.

Summary: Recently we described a biochemical cascade which is critical in promoting recovery sleep (RS) after sleep deprivation (SD). It is initially triggered in the basal forebrain (BF) and later in the prefrontal cortex (PFC). This cascade includes production of inducible nitric oxide synthase (iNOS)-dependent NO followed by an increase in adenosine (AD). We hypothesized that iNOS induction is triggered by an increase in extracellular glutamate (Glu), and that the increase in AD prevents further rise in Glu via its inhibitory action on AD A1 receptor (A1R). To test this hypothesis, during 8h of SD, we first examined the time course of Glu and AD in BF/PFC. Further, to investigate the role of BF Glu receptors (GluRs) in this cascade, we measured the changes in BF/PFC AD and NREMs/delta after: a) stimulating BF GluRs by NMDA or AMPA without SD; b) blocking BF GluRs during SD by NMDAR or AMPAR selective antagonists. Finally, we measured Glu in the BF/PFC after blocking A1R. Furthermore, to determine the cellular target of glutamate effects, we examined the effects BF AMPA infusion on BF/PFC AD and NREMs/delta after BF cholinergic (ChBF) lesions using 192 IgG-saporin. Male rats were implanted with EEG/EMG recording electrodes and microdialysis guide cannulae targeting the BF and PFC. Microdialysis samples were collected during 8h SD and/or drug infusion. AD and Glu were measured using high performance liquid chromatography (HPLC) and ultra HPLC. To block NMDAR/AMPAR/A1R we used dizoclipine (MK-801)/6,7- dinitroquinoxaline-2,3-dione (DNQX)/8 cyclopentyltheophylline (CPT), respectively. 1) In the BF, Glu dramatically increased at the beginning of SD, followed by increase in AD at 2 h of SD. When AD maximized at 4 h of SD, Glu concurrently decreased to baseline. High AD levels were maintained till the end of SD. In the PFC, Glu significantly increased within 2h of SD. When AD increased at 5 h of SD, Glu returned to the baseline. 2) BF AMPA mimicked the effects of SD by increasing AD in both BF and PFC. NREMs/delta increased post AMPA-infusion. NMDA was not effective. 3) BF DNQX prevented AD increase during SD in BF/PFC and attenuated RS. MK-801 did not show any effect. 4) CPT Infusion to the BF/PFC induced dramatic increase in Glu till the end of SD. 5) Lesion of ChBF prevented BF/PFC AD increase during AMPA infusion and attenuated NREMs/delta post-infusion. A rapid increase in Glu during SD may be a trigger for the induction of iNOS-NO-AD cascade in both the BF and PFC. AD via A1R exerts a negative feedback on Glu neurotransmission, preventing its further rise and potential toxicity during long-term SD. The effect of Glu on SDinduced changes is primarily mediated via AMPAR, located on ChBF cells.

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

Su Y, Bidlingmaier S, Lee NK, Liu B (2018) Combine phage antibody display library selection on patient tissue specimens with laser capture microdissection to identify novel human antibodies targeting clinically relevant tumor antigens. (eds. Hust M, Lim T). In: Phage Display. Methods in Molecular Biology. 1701:331-347. Humana Press, New York, NY. doi: 10.1007/978-1-4939-7447-4_18

Objective: To develop a technology that allows selection of phage antibody display libraries on tumor cells in situ residing in their natural tissue microenvironment.

Summary: Intracellular delivery of Immunotoxin was determined as follows: Immunotoxin was prepared by mixing biotinylated scFv with Streptavidin-ZAP (Cat. #IT-27) at a molar ratio of 1:1 and incubated on ice for 30 min. 50 μl of serially diluted immunotoxin was added to each well and incubated for 96 h at 37°C in 5% CO2. Cell growth medium were carefully removed from each well.

Usage: 100 μl of diluted CCK-8 was added to each well in the 96-well plates and incubated for 1–4 h at 37°C in 5% CO2. The absorbance was measured at 450 nm using a microtiter plate reader and the EC50 value determined using GraphPad Prism.

Related Products: Streptavidin-ZAP (Cat. #IT-27)

Fraser M, Fortier M, Foucher D, Roumier P, Brousseau P, Fournier M, Surette C, Vaillancourt C (2018) Exposure to low environmental concentrations of manganese, lead, and cadmium alters the serotonin system of blue mussels. Environ Toxicol Chem 37:192-200. doi: 10.1002/etc.3942 PMID: 28796292

Objective: To determine the effects of exposure to Mn, Pb, or Cd on serotonin levels, monoamine oxidase (MAO) activity, and serotonin transporter (SERT) levels in the blue mussel Mytilus edulis.

Summary: The results clearly indicate that low environmental concentrations of Mn, Pb, and Cd affect the serotonin system in blue mussels.

Usage: Membrane was exposed to anti-SERT primary antibody diluted 1:1000 in 5% PBS skimmed milk for 1.5 h at room temperature, then rinsed twice in deionized water, washed 3 times for 5 min in PBS, and rinsed 4 times in deionized water.

Related Products: SERT Mouse Monoclonal (Cat. #AB-N40)

Wang C, Zhang C, Zhou F, Gao L, Wang Y, Wang C, Zhang Y (2018) Angiotensin II induces monocyte chemoattractant protein-1 expression by increasing reactive oxygen species-mediated activation of the nuclear factor‑κB signaling pathway in osteoblasts. Mol Med Rep 17:1166-1172. doi: 10.3892/mmr.2017.7971 PMID: 29115506

Objective: To investigate the effect of angiotensin II (Ang II) on monocyte chemoattractant protein‑1 (MCP‑1) expression and the underlying mechanism in osteoblasts.

Summary: These data indicate that Ang II-enhanced ROS production and activated NF‑κB signaling via AT1R, thus upregulating MCP‑1 expression in osteoblasts.

Usage: Western Blot; the membranes were blocked with 5% fat‑free milk and probed with anti‑AT1R (1:600).

Related Products: Angiotensin II receptor (AT-1R) Rabbit Polyclonal, affinity-purified (Cat. #AB-N27AP)

Lindborg JA, Mack M, Zigmond RE (2017) Neutrophils are critical for myelin removal in a peripheral nerve injury model of Wallerian degeneration. J Neurosci 37(43):10258-10277. doi: 10.1523/JNEUROSCI.2085-17.2017 PMID: 28912156

Objective: To characterize Wallerian degeneration (WD) in male Ccr2−/−mice and identify a compensatory mechanism of WD that is facilitated primarily by neutrophils.

Summary: The data have shown that neutrophils play an impressive role in myelin removal during WD. Neutrophil-specific depletion severely abates nerve debris clearance not only in Ccr2−/− mice, but in WT mice as well. The findings show a novel role for neutrophils that better elucidates the process of WD in the peripheral nervous system.

Usage: immunohistochemistry (1:400)

Related Products: NGFR (mu p75) Rabbit Polyclonal, affinity-purified (Cat. #AB-N01AP)

Llorente-ovejero A, Manuel I, Giralt MT, Rodríguez-puertas R (2017) Increase in cortical endocannabinoid signaling in a rat model of basal forebrain cholinergic dysfunction. Neuroscience 362:206-218.. doi: 10.1016/j.neuroscience.2017.08.008

Objective: To evaluate the eCB signaling in relation to the memory impairment induced in adult rats following a specific cholinergic lesion of the basal forebrain.

Summary: CB1 receptors present in presynaptic GABAergic terminals in the hippocampus are down regulated, but not those in cortical glutamatergic synapses.

Usage: 192-IgG-SAP was dissolved in aCSF under aseptic conditions to a final concentration of 130 ng/ml. aCSF or 192-IgG-SAP was bilaterally injected (1 ml/hemisphere) at a constant rate of 0.2 ml/min.

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