References

Konig N, Trolle C, Kapuralin K, Adameyko I, Mitrecic D, Aldskogius H, Shortland PJ, Kozlova EN (2017) Murine neural crest stem cells and embryonic stem cell-derived neuron precursors survive and differentiate after transplantation in a model of dorsal root avulsion. J Tissue Eng Regen Med 11(1):129-137. doi: 10.1002/term.1893 PMID: 24753366

Objective: To compare survival and migration of murine boundary cap neural crest stem cells (bNCSCs) and embryonic stem cells (ESCs)-derived, pre-differentiated neuron precursors after their implantation acutely at the junction between avulsed dorsal roots L3-L6 and the spinal cord.

Summary: The data show that both stem cell types successfully survived implantation to the acutely injured spinal cord and maintained their differentiation and migration potential. The data suggest that, depending on the source of neural stem cells, they can play different beneficial roles for recovery after dorsal root avulsion.

Usage: immunohistochemistry (1:500)

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

Bolaina-Lorenzo E, Martínez-Ramos C, Monleón-Pradas M, Herrera-Kao W, Cauich-Rodríguez JV, Cervantes-Uc JM (2016) Electrospun polycaprolactone/chitosan scaffolds for nerve tissue engineering: physicochemical characterization and Schwann cell biocompatibility. Biomed Mater 12(1):015008. doi: 10.1088/1748-605x/12/1/015008 PMID: 27934786

Objective: To study the effect of scaffold compositions on its physicochemical and biological properties.

Summary: Immunochemistry analysis with p75 analysis confirmed that the cells exhibited a Schwann cell phenotype, suggesting that electrospun polycaprolactone/chitosan scaffolds would be good candidates for peripheral nerve tissue engineering.

Usage: IHC (1:100)

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

Turnbull M, Coulson E (2017) Cholinergic basal forebrain lesion decreases neurotrophin signaling without affecting tau hyperphosphorylation in genetically susceptible mice. J Alzheimers Dis 55:1141-1154.. doi: 10.3233/JAD-160805

Summary: Alzheimer’s disease(AD) is a progressive, irreversible neurodegenerative disease that destroys memory and cognitive function. Aggregates of hyperphosphorylated tau protein are a prominent feature in the brain of patients with AD, and area major contributor to neuronal toxicity and disease progression. However, the factors that initiate the toxic cascade that results in tau hyperphosphorylation in AD are unknown. The authors investigated whether degeneration of basal forebrain cholinergic neurons (BFCNs) and/or resultant decrease in neurotrophin signaling cause aberrant tau hyperphosphorylation. Two-month-old male and female pR5 mice were infused with murine p75-SAP (Cat. #IT-16) at a concentration of 0.4 mg/ml or 0.4 mg/ml of control Rabbit IgG-SAP (Cat. #IT-35) using a 30G needle attached to a 5 ml Hamilton syringe and pump. The needle was lowered into the medial septum according to coordinates in a mouse brain atlas, and the toxin was infused at a rate of 0.4 ul/min (1.5 u total volume). The results reveal that the loss of BFCNs in pre-symptomatic pR5 tau transgenic mice results in a decrease in hippocampal brain-derived neurotrophic factor levels and reduced TrkB receptor activation. However, there was no exacerbation of the levels of phosphorylated tau or its aggregation in the hippocampus of susceptible mice. Furthermore the animals’ performance in a hippocampal-dependent learning and memory task was unaltered, and no changes in hippocampal synaptic markers were observed. This suggests that tau pathology is likely to be regulated independently of BFCN degeneration and the corresponding decrease in hippocampal neurotrophin levels, although these features may still contribute to disease etiology.

Related Products: mu p75-SAP (Cat. #IT-16), Rabbit IgG-SAP (Cat. #IT-35)

Maass J, Gu R, Cai T, Wan Y, Cantellano S, Asprer J, Zhang H, Jen H, Edlund R, Liu Z, Groves A (2016) Transcriptomic analysis of mouse cochlear supporting cell maturation reveals large-scale changes in notch responsiveness prior to the onset of hearing. PLoS One 11:e0167286. doi: 10.1371/journal.pone.0167286 PMID: 27918591

Summary: The ability of neonatal mouse cochlear supporting cells to divide and differentiate into hair cells is very limited and declines in the first two weeks after birth. This decline is associated with the morphological and functional maturation of the organ of Corti prior to the onset of hearing, however little is known of the molecular changes that underlie these events. The authors attempt to identify these changes using RNA-seq to generate transcriptional profiles of purified cochlear supporting cells and found significant changes in gene expression related to regulation of proliferation, differentiation of inner ear components and the maturation of the organ of Corti. The authors also examined the regenerative potential of supporting cells in production of hair cells in response to a blockade of the Notch signaling pathway at the time of birth, but a complete lack of response just a few days later. Analysis included IHC on frozen sections of paraformaldehyde-fixed temporal bones of LfngEGFP mice. Anti-NGFr (mup75) (Cat. #AB-N01AP) was used at a 1:200 dilution. The results offer first molecular insights into the failure of hair cell regeneration in the mammalian cochlea.

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

Ha K, Bidlingmaier S, Su Y, Lee N, Liu B (2017) Identification of novel macropinocytosing human antibodies by phage display and high-content analysis. Methods Enzymol 585:91-110. doi: 10.1016/bs.mie.2016.10.004

Objective: To describe a method for identifying antibodies that internalize via macropinocytosis by screening phage-displayed single-chain antibody selection outputs with an automated fluorescent microscopy-based high-content analysis platform.

Summary: Novel phage antibodies are identified by colocalization with macropinocytosis marker, converted into full-length human antibodies, and further characterized with regard to cell binding, pathway of internalization, and intracellular payload delivery.

Usage: Biotinylated IgG is mixed with Streptavidin-ZAP in 1:1 molar ratio to form an immunotoxin that is serially-diluted in a cytotoxicity assay.

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Kelly SC, Nelson PT, Counts SE (2016) The locus coeruleus: a potential link between cerebrovascular and neuronal pathology in Alzheimer’s disease. Neuroscience 2016 Abstracts 786.11 / H7. Society for Neuroscience, San Diego, CA.

Summary: Noradrenergic locus coeruleus (LC) neuron loss is a major feature of Alzheimer’s disease (AD). The LC is the primary source of norepinephrine (NE) in the forebrain, where it modulates attention and memory in vulnerable cognitive regions such as prefrontal cortex and hippocampus. Furthermore, LC-mediated NE signaling is thought to play a role in blood brain barrier maintenance and neurovascular coupling, suggesting that LC degeneration may impact the high comorbidity of cerebrovascular disease (CVD) and AD. However, the extent to which LC projection system degeneration occurs in the earliest stages of AD is not fully characterized to date. To address these issues, we analyzed LC tissue samples from University of Kentucky AD Center subjects who died with a premortem diagnosis of no cognitive impairment (NCI) and Braak stages 0-II at autopsy, NCI subjects with Braak stages III-V thought to be in a preclinical AD (PCAD) stage, and subjects with mild cognitive impairment (MCI) or mild AD (n = 5-6 cases/group). Paraffin-embedded pontine tissue blocks containing the LC were cut at 20µm, immunostained with tyrosine hydroxylase (TH, a marker for NE synthesis), and analyzed by stereology to estimate total LC neuron number (total number of neuromelanin-containing LC neurons) and the percentage of TH+ LC neurons. Preliminary analysis reveal a ~20% loss of both total and TH+ LC neurons in PCAD (p = 0.08), a ~30-35% loss of these neurons in MCI (p < 0.05), and a ~45-50% loss of total and TH+ neurons in AD (p < 0.01) compared to NCI. Studies were also performed to compare additional LC neuronal pathologies (phospho-tau, TDP-43, and 8dOHG) in the diagnostic groups. A substantial increase in 8dOHG and phospho-tau is observed in PCAD compared to NCI. The morphometric data will be correlated with postmortem neuropathologic and CVD variables (e.g., microinfarcts and cerebral amyloid angiopathy) to gauge the relationship between LC neurodegeneration and cerebral AD and vascular pathology. To model these relationships in vivo, we stereotactically lesioned LC projection neurons innervating the PFC, a major LC projection zone, in the TgF344-19 rat model of AD (6 months old) using the noradrenergic immunotoxin, dopamine-β-hydroxylase-saporin, or a control lesion (n = 8/group). Prior to sacrifice at 9 months, immunotoxin- and control-lesioned rats will be tested behaviorally on the Barnes maze task. Postmortem PFC will be analyzed for LC fiber innervation, NE and NE metabolite levels, CVD pathology and AD-like pathology. Taken together, these data will shed light on the multifactorial noradrenergic pathways contributing to neuronal and vascular pathologies during the onset of AD.

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ATS Poster of the Year Winner. Read the featured article in Targeting Trends.

Ruiz AD, Hays S, Berry A, Vallejo S, Barron L, Carrier X (2016) Enhanced motor recovery by vagus nerve stimulation requires cholinergic innervation in a rat model of ischemic stroke. Neuroscience 2016 Abstracts 807.20 / HH11. Society for Neuroscience, San Diego, CA.

Summary: Stroke is a debilitating neurological insult that affects approximately 795,000 people in the U.S. each year. Following a stroke, many patients are left with impairment in upper extremity function, even after intensive rehabilitation therapy. Recent studies indicate that vagus nerve stimulation (VNS) paired with rehabilitative training significantly enhances recovery of forelimb function in models of ischemic stroke, intracerebral hemorrhage, and traumatic brain injury. Nevertheless, the mechanisms that underlie VNS-dependent enhancement recovery are largely unknown. The cholinergic nucleus basalis (NB) is a critical substrate in cortical plasticity, and several studies suggest that VNS activates cholinergic circuitry. Previous studies demonstrated that cholinergic innervation of the motor cortex is required for VNS-dependent enhancement of cortical plasticity. In this study we examine whether cholinergic innervation is required for VNS-dependent enhanced recovery in a rat model of ischemic stroke. A cohort of rats was trained to proficiency on the isometric force task, an automated and qualitative measure of forelimb function and then received a cortical ischemic lesion to impair the trained forelimb. Rats then received injections of the highly selective immunotoxin IgG-192-saporin into the nucleus basalis to deplete cortical cholinergic innervation (NB-) or control injections (NB+). Two weeks after stroke and immunolesion, rats underwent rehabilitative training for 6 weeks with or without VNS paired with forelimb movement. At the conclusion of behavioral testing, pseudorabies virus labelling was performed to assay anatomical plasticity in motor circuits controlling the forelimb. Preliminary findings indicate that VNS-dependent enhancement of stroke recovery requires cholinergic innervation.

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

Gulino R, Forte S, Parenti R, Gulisano M (2016) Novel targets for modulation of plasticity in a mouse model of motoneuron degeneration. Neuroscience 2016 Abstracts 812.14 / OO13. Society for Neuroscience, San Diego, CA.

Summary: A successful spinal cord repairing strategy should involve the activation of neural precursor cells. Unfortunately, their ability to generate neurons aſter injury appears limited. Another process promoting functional recovery is synaptic plasticity. We have previously studied some mechanisms of spinal plasticity by using a mouse model of motoneuron depletion induced by cholera toxin-B saporin. TDP-43 is a nuclear RNA/DNA binding protein involved in amyotrophic lateral sclerosis. Although considerable attention has been devoted to the toxic effects of the TDP-43 cytoplasmic aggregates, the functional role of this factor remains poorly investigated. Notably, TDP-43 is present in the dendrites where it behaves as a modulator of local RNA translation. Moreover, it is crucial for synaptic plasticity and locomotion in Drosophila. Here, we would like to deepen the investigation of this model of spinal plasticity. Aſter lesion, we observed a glial reaction and an activity-dependent modification of Synapsin-I, Shh, Noggin, Numb and TDP-43 proteins. Multivariate regression was used to model the possible association between these proteins, as well as with the motor performance. We found that Shh and Noggin could affect motor performance and that these proteins could be associated with both TDP-43 and Numb, thus suggesting that TDP-43 is likely an important regulator of synaptic plasticity. Given the well-known role of morphogens such as Shh, Noggin and Numb in neurogenesis and the above described functions of TDP-43, we believe that an in vivo manipulation of their signaling pathways after lesion could represent a putative method of improving regeneration and recovery by affecting synaptic plasticity and/or neurogenesis.

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Leong CS, Maness EB, Baraki DI, Burk JA (2016) Effects of protein kinase C activation on attention deficits following loss of corticopetal cholinergic neurons. Neuroscience 2016 Abstracts 833.03 / HHH22 . Society for Neuroscience, San Diego, CA.

Summary: Alzheimer’s disease (AD) is a neurodegenerative dementia characterized by memory loss, cognitive impairment, and attention deficits. Damage to corticopetal cholinergic neurons originating in the basal forebrain is thought to contribute to the attention deficits. Recent evidence had identified G-protein decoupling at the M1 muscarinic acetylcholine receptor as well as decreased levels of protein kinase C (PKC) in rat AD models and the human AD brain. PKC is a signaling kinase that can affect neurite outgrowth, synaptic formation, and neurotransmitter release. PKC activation additionally may affect voltage-gated calcium currents. Previous research in this lab has shown that inhibition of PKC by chelerythrine chloride decreased signal detection in a sustained attention task. The present experiment evaluates the effect of PKC activation on sustained attention following loss of cortical cholinergic projections induced by infusions of 192 IgG-saporin into the basal forebrain. Male and female Sprague-Dawley rats were trained to discriminate between signals (illumination of a central panel light) and nonsignals (no panel light illumination) in a two-lever sustained attention task. Each rat received intraventricular infusions of the PKC activator bryostatin-1 (0, 0.5, 2.0, and 4.0pM) prior to testing. In the middle block of trials, a flashing houselight distracter was included to increase attentional demands. Compared to sham-lesioned animals, lesioned animals showed poorer signal detection in the distracter block of the task, but no differential effects of lesion on nonsignal trials. Distracter scores (initial block of trials with no distracter – distracter block) were calculated for each behavioral measure. For signal detection, there was a dose × group interaction (F(3,30) = 3.069, p = 0.043). Bryostatin-1 attenuated signal detection deficits in lesioned animals. Sham-treated animals showed decreased performance with increased bryostatin-1 dosage. Following the highest bryostatin-1 dose, there were no difference in signal detection between the sham and lesioned animals. The present results support the hypothesis that Bryostatin-1 can improve performance in a visual attention task following damage to corticopetal cholinergic neurons.

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

Phillips KB, Sarter M (2016) Cholinergic-dependent shifts to cue-directed behavior. Neuroscience 2016 Abstracts 833.11 / HHH30. Society for Neuroscience, San Diego, CA.

Summary: Successful cue detection requires cortical cholinergic signaling. Recent evidence has elucidated the role of phasic, short-timescale, regionally-specific cholinergic signals, termed “cholinergic transients”, in cue detection. Cholinergic transients in the right prefrontal cortex were exclusively observed in trials in which cues were detected and when such trials followed non-cued trials yielding correct rejections or falsely perceived non-cued trials (cues that were missed). Thus, these cholinergic transients were interpreted as mediating shifts from performance guided by internally-guided attention to cued-directed behavior (Howe et al., 2013). In contrast to cholinergic transients mediating shift-hits, such transients were not observed during consecutive hits. Transients may be actively suppressed during consecutive hits in order to constrain a potential detection bias and maintain behavioral flexibility (Sarter et al., 2015). Here we removed cholinergic innervation to the right prefrontal cortex in rats to test the hypothesis that the right hemispheric cortical cholinergic projection system is necessary for shift-hits. Rats were trained on a sustained attention task (SAT) consisting of a random sequence of signal trials and non-signal trials, both requiring a distinct lever response from the subject. Following stable task performance, half of the subjects received right unilateral cholino-selective lesions of the basal forebrain by infusions of the immunotoxin 192 IgG-saporin, while the remaining subjects received sham surgeries. Rats were then familiarized with performing a modified version of SAT which consisted of engineered trial sequences to provide an “aggressive” test of the hypothesis based on the performance of pre-defined trials. In particular, the modified SAT included long strings of non-cued trials that were followed by a cued trial, with lesioned animals expected to miss specifically that latter trial. Conversely, neither hits during long strings of cued trials, nor correct rejections during non-cued trials that followed long strings of consecutive hits were expected to be affected by the lesion. Results indicate that right cholinergic losses selectively impair shift-hits. These findings are consistent with recent results from our optogenetic studies showing that cortical cholinergic transients are necessary and sufficient for the detection of cues (Gritton et al., 2016) and they extend these findings by specifying that in the absence of cortical cholinergic activity, subjects remain arrested in a state of perceptual or intrinsic attention.

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