Intracerebroventricular Injection Research Articles

Brazilian green propolis prevent Alzheimer’s disease-like cognitive impairment induced by amyloid beta in mice

BackgroundThe increasing incidence of cognitive impairment has become a health problem in the aging society. Owing to its antioxidant and anti-inflammatory properties, Brazilian green propolis—derived from Baccharis dracunculifolia—is anticipated to possess anticognitive properties. However, the preventive effect of Brazilian green propolis on cognitive impairment remains unexplained. This study aimed to investigate the effect of Brazilian green propolis on cognitive impairment using a mouse model of Alzheimer’s disease (AD) induced by intracerebroventricular injection of amyloid beta (Aβ)25‒35.MethodsFive-week-old male Slc:ddY mice were randomly divided into five groups (n = 8). The groups were pretreated with vehicle and propolis at a dose of 100, 300 and 900 mg/kg body weight for 8 days, then AD-like phenotypes were induced by intracerebroventricular (ICV) injection of Aβ25‒35. A sham operation group was set as the control. Memory and learning ability were measured at 7 to 8 days after ICV injection. Gene expression and histological studies were performed at the endpoint of the study.ResultsIn a passive avoidance test, the administration of Brazilian green propolis prevented the impairment of learning and memory function. Furthermore, comprehensive gene expression analysis in the hippocampus and forebrain cortex revealed that Brazilian green propolis suppressed Aβ25–35-induced inflammatory and immune responses. In particular, Brazilian green propolis prevented alterations in gene expressions of microglial and astrocytic markers such as Trem2 and Lcn2 induced by Aβ25‒35 injection, suggesting the suppression of excessive activation of glial cells in the brain. In addition, Brazilian green propolis suppressed the elevation of plasma interleukin (IL)-6 levels induced by Aβ25‒35 injection.ConclusionsThe results suggest that the prophylactic administration of Brazilian green propolis has a preventive effect against AD by suppressing excessive inflammation and immune response in glial cells. To our knowledge, this study is the first to demonstrate that Brazilian green propolis may inhibit the hyperactivation of microglia and astrocytes as a mechanism of action to prevent AD. Thus, it is a promising ingredient for preventing AD-type dementia.

Lactate entrance into the brain facilities adipose tissue lipolysis during exercise via circulating calcitonin gene-related peptide

Objectives: We assessed the relationships between CGRP, lactate and fat regulation. Methods: We evaluated the effect of intracerebroventricular (i.c.v.) injection of lactate and acute exercise on brain CGRP expression, and its concentration in serum/cerebrospinal fluid (SCF) in rats. Results: Injection of lactate up-regulated CGRP expression in the cortex and CSF and activated p38-mitogen-activated protein kinases (p38-MAPK) pathway. Co-injection of lactate and sb203580, deterred lactate-induced up-regulation of CGRP in the brain and CSF. Exercise increased the CGRP expression in the brain and CSF and up-regulated fat metabolism. Inhibition of lactate entrance into the brain using alpha-cyano-4-hydroxycinnamate (4-CIN) diminished exercise-induced CGRP up-regulation in the brain and CSF. Reducing the circulating blood lactate by pre-treatment of the animals with dichloroacetate (DCA) had no effect on exercise-induced increase in CGRP expression or fat metabolism during exercise.Conclusions: lactate probably acts as one of a signalling molecule in the brain to regulate fat metabolism during exercise.

Central effects of the serotoninergic, GABAergic, and cholecystokinin systems on neuropeptide VF (NPVF)-induced hypophagia and feeding behavior in neonatal broiler chicken

The study was performed to evaluate the role of central serotoninergic, GABAergic, and cholecystokinin systems in neuropeptide VF (NPVF)-induced hypophagia in broiler chickens. In this study, 9 experiments were designed, each with one control and three treatment groups (n = 44 in each experiment). Control chicks of all groups were subjected to normal saline + Evans blue 0.1 % Intracerebroventricular (ICV) injection. In the first experiment, 3 groups of chicks received NPVF (4, 8, and 16 nmol). In experiment 2–9, one group of chicks received NPVF (16 nmol), another received 10 µg fluoxetine (serotonin reuptake inhibitor) (experiment 2), 1.25 µg PCPA (serotonin synthesis inhibitor) (experiment 3), 1.5 µg SB-242,084 (5-HT2C receptor antagonist) (experiment 4), 15.25 nmol 8-OH-DPAT (5-HT1A receptor antagonist) (experiment 5), 0.5 µg picrotoxin (GABAA receptor antagonist) (experiment 6), 20 ng CGP54626 (GABAB receptor antagonist) (experiment 7), 1 nmol devazepide (CCKA receptor antagonist) (experiment 8), and 1 nmol/L−365(−|-),260 (CCKB receptor antagonist) (experiment 9), and another final group received combination of specific neurotransmitter + NPVF Then, the cumulative food intake was measured until 120 min post-injection. ICV injection of NPVF (8 and 16 nmol) significantly decreased food intake (P < 0.05). Simultaneous injection of fluoxetine + NPVF and also picrotoxin + NPVF significantly increased hypophagia caused by NPVF (P < 0.05). However, co-administration of PCPA + NPVF and also SB242084 + NPVF significantly decreased NPVF-induced hypophagia (P < 0.05). Finally, 8-OH-DPAT, CGP54626, devazepide, and L-365,260 had no effect on the hypophagia brought on by NPVF (P > 0.05). Count-type behaviors were dose-dependent and decreased in groups that received NPVF compared to the control group (P < 0.05). Our finding recommended an interconnection between central NPVF and serotoninergic, GABAergic, and cholecystokinin systems in neonatal chickens.

The Unfolded Protein Response in a Murine Model of Alzheimer's Disease: Looking for Predictors.

Alzheimer's disease (AD) represents the most frequent type of dementia worldwide, and aging is the most important risk factor for the sporadic form of the pathology. The endoplasmic reticulum (ER), the main cellular actor involved in proteostasis, appears significantly compromised in AD due to the accumulation of the β-amyloid (Aβ) protein and the phosphorylated Tau protein. Increasing protein misfolding activates a specific cellular response known as Unfolded Protein Response (UPR), which orchestrates the recovery of ER function. The aim of the present study was to investigate the role of UPR in a murine model of AD induced by intracerebroventricular (i.c.v.) injection of Aβ1-42 oligomers at 3 or 18 months. The oligomer injection in aged animals induced memory impairment, oxidative stress, and the depletion of glutathione reserve. Furthermore, the RNA sequencing and the bioinformatic analysis performed showed the enrichment of several pathways involved in neurodegeneration and protein regulations. The analysis highlighted the significant dysregulation of the protein kinase RNA-like ER kinase (PERK), inositol-requiring protein 1α (IRE1α) and activating transcription factor 6 (ATF-6). In turn, ER stress affected the PI3K/Akt/Gsk3β and MAPK/ERK pathways, highlighting Mapkapk5 as a potential marker, whose regulation could lead to the definition of new pharmacological and neuroprotective strategies to counteract AD.

TMIC-10. TGF-Β2 DRIVEN SURVIVAL IN DMG AND GBM

Abstract OT-101 is being developed as immunotherapy for a broad range of cancers. Cancers overexpress TGF-β, which suppresses host innate immune response to the cancers. Treatment with OT-101 lifts the TGF-β cloaking effect and allows innate or therapeutic immunity to attack and eliminate the cancers. OT-101 completed phase 2 for pancreatic cancer and melanoma and phase 2 in glioblastoma with robust efficacy and safety. Here we are presenting data and clinical trial design for OT-101 in DMG (Diffuse Midline Glioma). ADME studies were performed on OT-101 demonstrating perfusion of the brain including the midline by either intracerebral or intraventricular administration. The studies allowed us to bridge intraventricular administration to corpus of CED administered OT-101. Safety studies were performed in two species supporting the safety of OT-101 intraventricular administration. Expression analyses of pediatric brainstem cases of the TCGA database yielded highly significant survival benefit across all four quartiles of TGF-β2 expression. This was not observed for either TGF-β1 and less so for TGF-β3. Expression analyses of all gliomas treated with radiation yielded highly significant survival benefit across all four quartiles of TGF-β2 expression. This was not observed for either TGF-β1 nor TGF-β3. In adult gliomas, OT-101 is noninferior to the most active drugs (TMZ, BCNU, or PCV) in both chemo naïve and chemo-resistant patients. In terms of overall survival when compared to standard chemotherapy (TMZ, BCNU, or PCV) in both G004 and G005 as both the hazard ratio, which was 0.9168, and the 90% upper limit of the confidence interval, which was 1.2245, were both less than the initial non-inferiority bound of 1.25. Together the data support the development of OT-101 for DMG. The phase 2 clinical trial design is being presented for OT-101 in DMG administered using Ommaya reservoir following radiation in newly diagnosed DMG

DDEL-10. RETROSPECTIVE REVIEW OF INTRA-CSF DRUG DELIVERY: SAFETY AND DRUG DISTRIBUTION PROFILES OF INTRACEREBROVENTRICULAR (ICV), LUMBAR INTRATHECAL (LIT), AND INTRA-CISTERNA MAGNA (ICM) INJECTIONS

Abstract INTRODUCTION The blood-brain barrier and blood-CSF barrier limit the uptake of CNS-targeted therapeutics. Given this limitation, intra-cerebrospinal fluid (CSF) drug delivery can be utilized. Here we review and compare thesafety and drug distribution of the different intra-CSF drug delivery methods. METHODS A retrospective literature review of the three most common CSF access methods (intracerebroventricular (ICV), lumbar intrathecal (LIT), and intra-cisterna magna (ICM)) was performed. The search consisted of human clinical trials published on PubMed from 2000 to present, with the following terms: intracerebroventricular/intraventricular/ICV, intrathecal/IT, cisterna magna/ICM/IT-CM, drug delivery, drug administration, and CSF. RESULTS The search yielded 34 ICV, 72 LIT, and 6 ICM studies. To investigate the safety and drug concentration profiles of each delivery method, we excluded studies reporting drug adverse events (AEs) rather than AEs related to the specific drug delivery method, leaving 21 ICV, 30 LIT, and 1 ICM studies, all of which spanned oncology and non-oncology treatment studies. ICV-specific safety was addressed in 10 ICV studies, with infection (N=6) and device malfunction (N=2) being among the most frequently mentioned device/procedure-associated AEs. LIT-specific safety was provided in 17 studies, with post-procedural headache (N=9), infection (N=5), and pain (N=5) being among the most mentioned AEs. For drug distribution, 42.9% (N=9) of ICV studies concluded that ICV delivery achieved sufficient drug exposure in the CNS for a meaningful therapeutic benefit, with drug concentrations reaching minimum effective doses and/or achieving high therapeutic indices. The single ICM study with infusion of bupivacaine for pain management did not analyze safety or drug distribution. Meanwhile, 30.0% (N=9) of LIT studies reached the same conclusion or achieved concentrations consistent with predicted values. CONCLUSION The safety profiles of both ICV and LIT injections are acceptable, showing mostly mild-to-moderate device/procedure-associated AEs. Additionally, ICV achieves therapeutic goals more consistently than the other intra-CSF delivery methods.

INNV-01. ASSESSMENT OF SURVIVAL AND SAFETY FOLLOWING INTRATHECAL CHEMOTHERAPY VIA OMMAYA RESERVOIR FOR PATIENTS WITH LEPTOMENINGEAL DISEASE

Abstract BACKGROUND Leptomeningeal disease (LMD) carries poor prognosis with an average survival of 3-6 months after diagnosis. Ommaya reservoirs (OR) are an accessible alternative to serial lumbar punctures for delivery of intrathecal chemotherapy (IC) and disease monitoring but are not widely used. Intraventricular administration of chemotherapy may be associated with superior efficacy and improved patient comfort. The purpose of this study was to assess safety and efficacy of IC and disease monitoring via OR in routine clinical practice. METHODS Patients who received at least one administration of IC via OR for LMD between 2017 and 2022 were included. Demographics, treatment type, complications and outcomes were recorded. RESULTS We identified 22 patients (17 females, 5 males) with mean age 50.9 ± 14.8 years. The primary tumors were: breast (12), leukemia (3), ovarian carcinoma (3), CNS lymphoma (1), urothelial carcinoma (1), spinal melanocytoma (1), and high-grade glioma (1). A total of 208 OR injections were performed [median was 9 OR injections per patient, interquartile range (IQR) (5, 13)]. Five patients (23%) experienced mild adverse events of grade 2 or lower by Common Terminology Criteria for Adverse Events. Overall risk of adverse event from injection was 3.4% (7/208). Eight patients (36.3%) converted into negative CSF cytology (median 1 month following first injection). Eighteen patients (82%) had clinical or radiological progression of their LMD (median 2 months following first injection). Eleven patients (50%) died of their LMD during follow-up. Median OS and PFS from the first injection were 5.3 months [95% CI 4.8-NE (not estimable)] and 4.3 months [95% CI 1.8-16.0], respectively. CONCLUSION Use of OR in routine clinical practice is a safe and feasible option and should be strongly considered for treatment and monitoring of patients with LMD. The median OS in our cohort is comparable to prior published series.

Neuronal pyroptosis mediated by STAT3 in early brain injury after subarachnoid hemorrhage

Neuroinflammation induced by early brain injury (EBI) seriously affects the prognosis of patients after subarachnoid hemorrhage (SAH). Pyroptosis can aggravate inflammatory injury by promoting the secretion of inflammatory cytokines. Meanwhile, STAT3 plays a critical role in the inflammatory response of EBI after SAH. However, whether it plays a pyroptotic role in SAH is mainly unknown. This study aimed to explore the mechanism of STAT3 in pyroptosis in EBI after SAH. C57BL/6J mice were used to establish the SAH model. Brain tissues were collected at different time points for q-RT-PCR and western blot to detect the expression level of STAT3. After intracerebroventricular injection of STAT3 inhibitor S3I-201, they were divided into sham, SAH, SAH + Vehicle, and SAH + S3I-201. Then, the SAH grade, cerebral edema content, blood–brain barrier (BBB) damage, and neurological scores of mice in each group were detected. qRT-PCR and western blot were used to detect related genes and proteins, and enzyme-linked immunosorbent assay (ELISA) was used to detect the expression levels of IL-18 and IL-1β. Immunofluorescence staining was used to observe the expression level of proteins. At the same time, S3I-201 was added to the primary neuron cells of the culture medium containing OxyHb to simulate the in vitro experiment, and the relevant indicators consistent with the in vivo experiment were detected. The expression of STAT3 was upregulated after SAH. Inhibition of STAT3 with S3I-201 attenuated neurological deficits, cerebral edema, and BBB damage after SAH. In addition, S3I-201 can also reduce the expression of pyroptosis-related inflammasomes such as GSDMD, NLRP3, Caspase 1, and AIM2 after SAH and the neurological damage caused by IL-18 and IL-1β. Further studies have shown that STAT3 regulates pyroptosis by promoting the nuclear translocation of NF-κB p65. Our finding demonstrated that STAT3 regulates neuronal pyroptosis in EBI after SAH. Inhibition of STAT3 may be a potential target to attenuate the damage that triggers neuroinflammation after SAH.

Subject classification and cross-time prediction based on functional connectivity and white matter microstructure features in a rat model of Alzheimer’s using machine learning

BackgroundThe pathological process of Alzheimer’s disease (AD) typically takes decades from onset to clinical symptoms. Early brain changes in AD include MRI-measurable features such as altered functional connectivity (FC) and white matter degeneration. The ability of these features to discriminate between subjects without a diagnosis, or their prognostic value, is however not established.MethodsThe main trigger mechanism of AD is still debated, although impaired brain glucose metabolism is taking an increasingly central role. Here, we used a rat model of sporadic AD, based on impaired brain glucose metabolism induced by an intracerebroventricular injection of streptozotocin (STZ). We characterized alterations in FC and white matter microstructure longitudinally using functional and diffusion MRI. Those MRI-derived measures were used to classify STZ from control rats using machine learning, and the importance of each individual measure was quantified using explainable artificial intelligence methods.ResultsOverall, combining all the FC and white matter metrics in an ensemble way was the best strategy to discriminate STZ rats, with a consistent accuracy over 0.85. However, the best accuracy early on was achieved using white matter microstructure features, and later on using FC. This suggests that consistent damage in white matter in the STZ group might precede FC. For cross-timepoint prediction, microstructure features also had the highest performance while, in contrast, that of FC was reduced by its dynamic pattern which shifted from early hyperconnectivity to late hypoconnectivity.ConclusionsOur study highlights the MRI-derived measures that best discriminate STZ vs control rats early in the course of the disease, with potential translation to humans.

Effects of intracerebroventricular administration of calcitonin gene-related peptide (CGRP) on sex hormones and sperm quality in rats.

Therapeutic strategies with calcitonin gene-related peptide (CGRP) or its receptor have been investigated, but there are few studies regarding the possible harmful effects of CGRP in other body organs. This study aimed to investigate the effect of intracerebroventricular (ICV) injection of CGRP on sex hormones and sperm quality in rats. Twelve male rats were divided into two groups (n=6 per group). The first group (control) rats were injected with 5µl artificial cerebrospinal fluid intra-ICV; the second group rats, 5µl (1.5nmol) CGRP. The levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone were measured. Epididymal sperms were used to determine the sperm parameters. The levels of testosterone, LH and FSH in CGRP group was significantly lower than in artificial cerebrospinal fluid (ACSF) group (P<0.05). The concentration and motility of sperm in CGRP group was significantly lower than in ACSF group (P<0.05). In CGRP group live spermatozoa and intact acrosome significantly reduced compared to the ACSF group (P<0.05). In addition, in CGRP group dead spermatozoa and lose acrosome significantly increased compared to the ACSF group (P<0.05). ICV injection of CGRP may reduce sperm quality, probably through induction of an imbalance in FSH and LH production as well as testosterone.

Pharmacological Inhibition of the AQP4 Water Channel Activity Causes an Aggravation of Alpha-Synuclein Pathology in the Substantia Nigra in a Rat Model of Parkinson’s Disease

The misfolding of the protein α-synuclein, which leads to the formation of neurototoxic oligomers and aggregates, is one of the main causes of loss of dopaminergic (DA) neurons within the substantia nigra pars compacta (SNpc) in Parkinson’s disease (PD). We previously found that pharmacological inhibition of the water channel aquaporin-4 (AQP4), participating in the mechanisms of brain clearance of amyloidogenic proteins, caused the aggravation of neurodegeneration in the nigrostriatal system and the development of motor disturbances in a lactacystin model of PD. It was hypothesized that the progression of neurodegeneration can be a result of the excessive accumulation of pathologic forms of α-synuclein due to the AQP4 inhibition. The aim of this study is to determine whether pharmacological inhibition of AQP4 activity in a rat model of preclinical PD leads to an aggravation in α-synuclein pathology. The experiments were performed on male Wistar rats. AQP4 activity was suppressed using the intracerebroventricular injection of inhibitor TGN-020. To reproduce the model of the preclinical stage of PD, a specific proteasome inhibitor lactacystin (LC) was used. It was injected bilaterally into the SNpc. Immunoblotting methods and confocal microscopy were applied. The LC model of PD was characterized by a pathologic accumulation of total water-soluble and Ser129-phosphorylated forms of α-synuclein, as well as by formation of insoluble α-synuclein aggregates in the DA-neurons of SNpc. TGN-020 caused a significant aggravation of α-synuclein pathology in the LC model of PD. It was manifested by a marked increase in the level of water-soluble and modified forms of α-synuclein and by the 1.9-fold rise in the amount of α-synuclein aggregates in SN. We suppose that the disfunction of AQP4 which is involved in glymphatic system functioning, can be one of the mechanisms leading to the neurodegeneration and accumulation of amyloidogenic proteins in brain parenchyma during PD. The water channel AQP4 might be a target for the development of new therapeutic approaches aimed at attenuation of the cytotoxicity, accumulation and distribution of α-synuclein during the development of PD-like pathology.

Deleterious and protective effects of epothilone-D alone and in the context of amyloid β- and tau-induced alterations.

Amyloid-β (Aβ) and hyperphosphorylated tau (P-tau) are Alzheimer's disease (AD) biomarkers that interact in a complex manner to induce most of the cognitive and brain alterations observed in this disease. Since the neuronal cytoskeleton is a common downstream pathological target of tau and Aβ, which mostly lead to augmented microtubule instability, the administration of microtubule stabilizing agents (MSAs) can protect against their pathological actions. However, the effectiveness of MSAs is still uncertain due to their state-dependent negative effects; thus, evaluating their specific actions in different pathological or physiological conditions is required. We evaluated whether epothilone-D (Epo-D), a clinically used MSA, rescues from the functional and behavioral alterations produced by intracerebroventricular injection of Aβ, the presence of P-tau, or their combination in rTg4510 mice. We also explored the side effects of Epo-D. To do so, we evaluated hippocampal-dependent spatial memory with the Hebb-Williams maze, hippocampal CA1 integrity and the intrinsic and synaptic properties of CA1 pyramidal neurons with the patch-clamp technique. Aβ and P-tau mildly impaired memory retrieval, but produced contrasting effects on intrinsic excitability. When Aβ and P-tau were combined, the alterations in excitability and spatial reversal learning (i.e., cognitive flexibility) were exacerbated. Interestingly, Epo-D prevented most of the impairments induced Aβ and P-tau alone and combined. However, Epo-D also exhibited some side effects depending on the prevailing pathological or physiological condition, which should be considered in future preclinical and translational studies. Although we did not perform extensive histopathological evaluations or measured microtubule stability, our findings show that MSAs can rescue the consequences of AD-like conditions but otherwise be harmful if administered at a prodromal stage of the disease.

The regulatory role of central neuropeptide-S in locomotion

Central exogenous Neuropeptide-S (NPS) was demonstrated to increase locomotor activity (LMA) in rodent studies. NPS receptor (NPSR) is produced in locomotion-related brain regions including basal ganglia while NPS mediates dopaminergic neurotransmission suggesting that endogenous brain NPS is involved in the regulation of locomotion. Aim of the study was to elucidate whether antagonism of NPSR impairs locomotion and to determine the neurochemical profile of NPSR-expressing cells in basal ganglia network. In the rats received intracerebroventricular injection of selective non-peptide NPSR antagonist ML154 (20 nmol/5 µL) or vehicle, in addition to measurement of catalepsy, motor performance, and motor coordination were evaluated by assessment of LMA and RR test, respectively. The immunoreactivities for NPSR, tyrosine hydroxylase (TH), glutamate decarboxylase 67 (GAD67), and choline acetyltransferase (ChAT) were detected by immunofluorescence in frozen sections. Compared to the control rats, total LMA was significantly declined following ML154 administration. The ML154-injected rats were more prone to fall in rotarod (RR) test, while they exhibited remarkably high catalepsy time. The most robust immunoreactivity for NPSR was detected in globus pallidus externa (GPe), while moderate levels of NPSR expression were observed in substantia nigra pars compacta (SNpc) and ventral tegmental area (VTA), but not in striatum. The NPSR-ir cell bodies were found to express GAD67 in GPe and TH in SNpc and VTA, respectively. NPSR expression was detected in SNpc-projecting pallidal cells. The present findings indicate the regulatory role of central endogenous NPS in the control of locomotion. NPSR may be a potential therapeutic target for the treatment of movement disorders.

Antisense oligonucleotides restore excitability, GABA signalling and sodium current density in a Dravet syndrome model.

Dravet syndrome is an intractable developmental and epileptic encephalopathy caused by de novo variants in SCN1A resulting in haploinsufficiency of the voltage-gated sodium channel Nav1.1. We showed previously that administration of the antisense oligonucleotide STK-001, also called ASO-22, generated using targeted augmentation of nuclear gene output technology to prevent inclusion of the nonsense-mediated decay, or poison, exon 20N in human SCN1A, increased productive Scn1a transcript and Nav1.1 expression and reduced the incidence of electrographic seizures and sudden unexpected death in epilepsy in a mouse model of Dravet syndrome. Here, we investigated the mechanism of action of ASO-84, a surrogate for ASO-22 that also targets splicing of SCN1A exon 20N, in Scn1a+/- Dravet syndrome mouse brain. Scn1a +/- Dravet syndrome and wild-type mice received a single intracerebroventricular injection of antisense oligonucleotide or vehicle at postnatal Day 2. We examined the electrophysiological properties of cortical pyramidal neurons and parvalbumin-positive fast-spiking interneurons in brain slices at postnatal Days 21-25 and measured sodium currents in parvalbumin-positive interneurons acutely dissociated from postnatal Day 21-25 brain slices. We show that, in untreated Dravet syndrome mice, intrinsic cortical pyramidal neuron excitability was unchanged while cortical parvalbumin-positive interneurons showed biphasic excitability with initial hyperexcitability followed by hypoexcitability and depolarization block. Dravet syndrome parvalbumin-positive interneuron sodium current density was decreased compared to wild-type. GABAergic signalling to cortical pyramidal neurons was reduced in Dravet syndrome mice, suggesting decreased GABA release from interneurons. ASO-84 treatment restored action potential firing, sodium current density and GABAergic signalling in Dravet syndrome parvalbumin-positive interneurons. Our work suggests that interneuron excitability is selectively affected by ASO-84. This new work provides critical insights into the mechanism of action of this antisense oligonucleotide and supports the potential of antisense oligonucleotide-mediated upregulation of Nav1.1 as a successful strategy to treat Dravet syndrome.

Intraventricular endoscopy and intraventricular antibiotics in the treatment of multiloculated hydrocephalus with ventriculitis in a neonate and an infant: Two case reports

Background: We present two pediatric cases, a neonate and an infant, who presented with treatment-refractory ventriculitis and multiloculated hydrocephalus treated with simultaneous intraventricular endoscopy and antibiotics. This is the first report of this combined therapy in children. Case Description: Using intraventricular endoscopic surgery and antibiotics, hydrocephalus was treated with a minimum number of ventricular shunt systems. In addition, treatment-refractory ventriculitis was treated in both patients using intraventricular antibiotics. Conclusion: Endoscopic surgery and intraventricular antibiotic administration are useful strategies for treating multiloculated hydrocephalus and ventriculitis in children.

Annexin A1 exerts analgesic effect in a mouse model of medication overuse headache

Medication overuse headache (MOH) is a serious global condition. The interaction between headache attacks and medication overuse complicates the understanding of its pathophysiology. In this study, we developed a preclinical MOH model that incorporates these two key factors by overusing rizatriptan benzoate (RIZ, 4mg/kg, i.g.) in a glyceryl trinitrate (GTN, 10mg/kg, i.p.) induced chronic migraine mouse model. We observed that RIZ overuse aggravated GTN-induced cutaneous allodynia and caused a prolonged state of latent sensitization. We also detected a significant upregulation of Annexin-A1 (ANXA1), a protein mainly expressed in the microglia of the spinal trigeminal nucleus caudalis (SPVC), in GTN+RIZ mice. Intracerebroventricular injection of ANXA1-derived peptide Ac2-26 trifluoroacetic acid (TFA) (5μg/mouse) inhibited bright light stress (BLS) induced acute allodynia via the formyl peptide receptor (FPR) in GTN+RIZ mice. These results suggest that ANXA1 may have an analgesic effect in triptan-associated MOH and could potentially serve as a therapeutic target.

SAT650 Catecholamine-independent Neural Pathways Drive The Rapid Catabolism Of Metabolically Inert Fat

Abstract Disclosure: X. Zhang: None. A. Majumdar: None. B. Kleiboeker: None. K.L. Magee: None. B.S. Learman: None. S.A. Thomas: None. I.J. Lodhi: None. O.A. MacDougald: None. E.L. Scheller: None. Adipocytes classically store or release energy in response to changes in metabolic status. However, several fat depots throughout the body are resistant to these metabolic cues. Identification of novel mechanisms that drive energy release from metabolically inert adipocytes is needed to inform strategies to deplete stubborn fat and, conversely, to preserve these depots in pathologic settings of wasting and cachexia. To address this question, we focused on the constitutive bone marrow adipose tissue (cBMAT), a well-established site of metabolically inert fat that remains unchanged with fasting, exercise, and cold exposure and is depleted only in certain extreme conditions such as cachexia or starvation. To study this unique depot, we developed a mouse model of rapid, complete depletion of all fat, including cBMAT, within 9 days using central intracerebroventricular (ICV) injection of leptin. Surgical denervation, chemical sympathectomy, or genetic dopamine beta-hydroxylase (DBH) deletion did not prevent the ICV leptin-induced depletion of cBMAT, revealing this process to be independent of catecholamines and the sympathetic nervous system (SNS). Vossicle implantation defined the mediators as transported through the circulation, and BMAT-specific ablation of adipose triglyceride lipase (ATGL) identified dependence on basal lipolysis. Gene expression and a radioisotope-based de novo lipogenesis assay pinpointed a concurrent suppression of lipogenesis, and subcutaneous insulin supplementation prevented leptin-induced cBMAT depletion, but not other depots. Together, this defines the differential regulation of metabolism in metabolically inert fat depots such as cBMAT. Specifically, leptin-responsive circuits in the brain can deplete inert adipocytes by suppressing lipogenesis while maintaining basal lipolysis independent of the SNS. Presentation: Saturday, June 17, 2023

Superiority of the Triple-Acting 5-HT6R/5-HT3R Antagonist and MAO-B Reversible Inhibitor PZ-1922 over 5-HT6R Antagonist Intepirdine in Alleviation of Cognitive Deficits in Rats.

The multifactorial origin and neurochemistry of Alzheimer's disease (AD) call for the development of multitarget treatment strategies. We report a first-in-class triple acting compound that targets serotonin type 6 and 3 receptors (5-HT-Rs) and monoamine oxidase type B (MAO-B) as an approach for treating AD. The key structural features required for MAO-B inhibition and 5-HT6R antagonism and interaction with 5-HT3R were determined using molecular dynamic simulations and cryo-electron microscopy, respectively. Bioavailable PZ-1922 reversed scopolamine-induced cognitive deficits in the novel object recognition test. Furthermore, it displayed superior pro-cognitive properties compared to intepirdine (a 5-HT6R antagonist) in the AD model, which involved intracerebroventricular injection of an oligomeric solution of amyloid-β peptide (oAβ) in the T-maze test in rats. PZ-1922, but not intepirdine, restored levels of biomarkers characteristic of the debilitating effects of oAβ. These data support the potential of a multitarget approach involving the joint modulation of 5-HT6R/5-HT3R/MAO-B in AD.

Kaempferol treatment ameliorates memory impairments in STZ‑induced neurodegeneration by acting on reelin signaling.

Many treatment initiatives, like herbal products and their active ingredients, aim to alleviate neurodegeneration to increase cognitive functions. Kaempferol may be a candidate molecule for treating neurodegeneration because of its antioxidant effects. In the present study, we examined the molecular changes associated with kaempferol's memory‑enhancing effects on streptozotocin (STZ)‑induced neurodegeneration. After intracerebroventricular STZ injection in Long‑Evans male rats, intraperitoneal kaempferol was administered for 12 days. The Morris water maze (MWM) was used to measure learning and memory performance in the rats, and proteins related to memory formation were investigated in the hippocampi with western blotting. Kaempferol improved learning performance and memory decline in STZ‑treated rats. At the molecular level, STZ‑induced neurodegeneration resulted in a decrease in the expression of GAD67, reelin, and phosphorylated‑NMDAR. However, kaempferol treatment ameliorated these changes by enhancing their levels similar to the controls. While neither STZ injection nor kaempferol treatment produced any significant change in phosphorylated‑CAMKII levels, they increased the expression of klotho and prealbumin. These results show that kaempferol has positive effects on memory loss, affecting synaptic plasticity by ameliorating both the levels and activity of memory‑relevant molecules through reelin signaling. In summary, this study provides a guide to future studies by examining in detail the healing effect of kaempferol as a candidate molecule in the treatment of neurodegeneration, such as that observed in Alzheimer's disease.

A Versatile Strategy for Genetic Manipulation of Cajal-Retzius Cells in the Adult Mouse Hippocampus.

Cajal-Retzius (CR) cells are transient neurons with long-lasting effects on the architecture and circuitry of the neocortex and hippocampus. Contrary to the prevailing assumption that CR cells completely disappear in rodents shortly after birth, a substantial portion of these cells persist in the hippocampus throughout adulthood. The role of these surviving CR cells in the adult hippocampus is largely unknown, partly because of the paucity of suitable tools to dissect their functions in the adult versus the embryonic brain. Here, we show that genetic crosses of the ΔNp73-Cre mouse line, widely used to target CR cells, to reporter mice induce reporter expression not only in CR cells, but also progressively in postnatal dentate gyrus granule neurons. Such a lack of specificity may confound studies of CR cell function in the adult hippocampus. To overcome this, we devise a method that not only leverages the temporary CR cell-targeting specificity of the ΔNp73-Cre mice before the first postnatal week, but also capitalizes on the simplicity and effectiveness of freehand neonatal intracerebroventricular injection of adeno-associated virus. We achieve robust Cre-mediated recombination that remains largely restricted to hippocampal CR cells from early postnatal age to adulthood. We further demonstrate the utility of this method to manipulate neuronal activity of CR cells in the adult hippocampus. This versatile and scalable strategy will facilitate experiments of CR cell-specific gene knockdown and/or overexpression, lineage tracing, and neural activity modulation in the postnatal and adult brain.