Publications by authors named "Alachkar A"

Primary cilia are dynamic sensory organelles that continuously undergo structural modifications in response to environmental and cellular signals, many of which exhibit rhythmic patterns. Building on our previous findings of rhythmic cilia-related gene expression in diurnal primates (baboon), this study extends the investigation to the nocturnal mouse brain to identify circadian patterns of cilia gene expression across brain regions. We used computational techniques and transcriptomic data from four publicly available databases, to examine the circadian expression of cilia-associated genes within six brain areas: brainstem, cerebellum, hippocampus, hypothalamus, striatum, and suprachiasmatic nucleus.

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Article Synopsis
  • Dopamine has traditionally been seen as the main neurotransmitter for motor functions, but this study reveals that non-dopaminergic mechanisms also play a significant role, particularly in Parkinson's disease models.
  • L-DOPA showed a strong motor response even when dopamine production was blocked, with an interesting pattern of delayed intensity and a duration that lasted longer than expected.
  • The research identified ophthalmic acid as a crucial metabolite that boosts motor activity in mice, and it was found to activate the calcium-sensing receptor (CaSR), suggesting new pathways for understanding and treating movement disorders.
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The dopamine D receptor 7-repeat allele (D R) has been linked with psychiatric disorders such as attention-deficit-hyperactivity disorder, autism, and schizophrenia. However, the highly diverse study populations and often contradictory findings make it difficult to draw reliable conclusions. The D R has the potential to explain individual differences in behavior.

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Chronic hypoxia may have a huge impact on the cardiovascular and renal systems. Advancements in microscopy, metabolomics, and bioinformatics provide opportunities to identify new biomarkers. In this study, we aimed at elucidating the metabolic alterations in kidney tissues induced by chronic hypoxia using untargeted metabolomic analyses.

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Research shows that brain circuits controlling vital physiological processes are closely linked with endogenous time-keeping systems. In this study, we aimed to examine oscillatory gene expression patterns of well-characterized neuronal circuits by reanalyzing publicly available transcriptomic data from a spatiotemporal gene expression atlas of a non-human primate. Unexpectedly, brain structures known for regulating circadian processes (e.

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In this study, we conducted high-throughput spatiotemporal analysis of primary cilia length and orientation across 22 mouse brain regions. We developed automated image analysis algorithms, which enabled us to examine over 10 million individual cilia, generating the largest spatiotemporal atlas of cilia. We found that cilia length and orientation display substantial variations across different brain regions and exhibit fluctuations over a 24-hour period, with region-specific peaks during light-dark phases.

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Voltage-gated potassium (Kv) channels formed by α subunits KCNQ2-5 are important in regulating neuronal excitability. We previously found that GABA directly binds to and activates channels containing KCNQ3, challenging the traditional understanding of inhibitory neurotransmission. To investigate the functional significance and behavioral role of this direct interaction, mice with a mutated KCNQ3 GABA binding site (Kcnq3-W266L) were generated and subjected to behavioral studies.

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Almost all brain cells contain cilia, antennae-like microtubule-based organelles. Yet, the significance of cilia, once considered vestigial organelles, in the higher-order brain functions is unknown. Cilia act as a hub that senses and transduces environmental sensory stimuli to generate an appropriate cellular response.

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Sunlight held the key to the origin of life on Earth. The earliest life forms, cyanobacteria, captured the sunlight to generate energy through photosynthesis. Life on Earth evolved in accordance with the circadian rhythms tied to sensitivity to sunlight patterns.

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The high overlapping nature of various features across multiple mental health disorders suggests the existence of common psychopathology factor(s) (p-factors) that mediate similar phenotypic presentations across distinct but relatable disorders. In this perspective, we argue that circadian rhythm disruption (CRD) is a common underlying p-factor that bridges across mental health disorders within their age and sex contexts. We present and analyze evidence from the literature for the critical roles circadian rhythmicity plays in regulating mental, emotional, and behavioral functions throughout the lifespan.

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Alzheimer's disease (AD) is a neurodegenerative disease characterized by Amyloid-β peptide (Aβ) containing plaques and cognitive deficits. The pathophysiology of AD also involves neuroinflammation. Vitamin B1 (thiamin) is indispensable for normal cellular energy metabolism.

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The disruption of methionine (L-MET) metabolism has been linked with neurodevelopmental disorders such as autism and schizophrenia and neurodegenerative disorders such as Alzheimer's disorder. We previously showed that repeated administration to adult mice of methionine produced impairments of cognitive deficits. Considering the decreased neurogenesis and increased molecular inflammation hypotheses of cognitive deficits in Alzheimer's, we aimed to explore whether the methionine regimen that produced cognitive deficits is associated with altered neuroinflammation, neurogenesis, or neurodegeneration.

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There is a growing demand for real-time analysis and sampling of biofluids on a single low-cost platform in ultralow fluid volumes with robustness. In this study, a microfluidic sensor was developed, manufactured through an additive manufacturing technique, and used for dopamine (DA) measurements. We implemented a biosensing system using pencil graphites (PGEs) integrated into a three-dimensional (3D) printed microfluidic syringe-type device (μSyringe).

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Ciliary extracellular vesicles (ciEVs), released from primary cilia, contain functional proteins that play an important role in cilia structure and functions. We have recently shown that ciEVs and cytosolic extracellular vesicles (cyEVs) have unique and distinct biomarkers. While ciEV biomarkers have shown some interactions with known ciliary proteins, little is known about the interaction of ciEV proteins with proteins involved in ciliopathy and neurodegenerative disorders.

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l-3,4-Dihydroxyphenylalanine (l-DOPA), the dopamine precursor, remains the frontline treatment for Parkinson's disease (PD). With the treatment progress, l-DOPA efficacy decreases, necessitating higher and more frequent doses, with higher risks of dyskinesia. l-DOPA chelates iron through its catechol group, forming the l-DOPA:Fe complex; however, the fate of this complex is unknown.

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G-protein-coupled receptors (GPCRs) play an integral role in the neurobiology of psychiatric disorders. Almost all neurotransmitters involved in psychiatric disorders act through GPCRs, and GPCRs are the most common targets of therapeutic drugs currently used in the treatment of psychiatric disorders. However, the roles of GPCRs in the etiology and pathophysiology of psychiatric disorders are not fully understood.

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The melanin-concentrating hormone (MCH) system is involved in numerous functions, including energy homeostasis, food intake, sleep, stress, mood, aggression, reward, maternal behavior, social behavior, and cognition. In rodents, MCH acts on MCHR1, a G protein-coupled receptor, which is widely expressed in the brain and abundantly localized to neuronal primary cilia. Cilia act as cells' antennas and play crucial roles in cell signaling to detect and transduce external stimuli to regulate cell differentiation and migration.

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Article Synopsis
  • Almost all brain cells have primary cilia, which are essential sensory organelles that help with brain formation during development and function as signaling hubs in the adult brain.
  • A study analyzed cilia gene expression across 16 brain regions throughout human life, revealing that 67% of the cilia-related genes change with age, showing patterns specific to different brain areas.
  • Findings indicate that many cilia genes are upregulated with age, particularly components related to cilia structure, and highlight the relationship between cilia expression and age-related neurological disorders.
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Cilia are dynamic subcellular systems, with core structural and functional components operating in a highly coordinated manner. Since many environmental stimuli sensed by cilia are circadian in nature, it is reasonable to speculate that genes encoding cilia structural and functional components follow rhythmic circadian patterns of expression. Using computational methods and the largest spatiotemporal gene expression atlas of primates, we identified and analyzed the circadian rhythmic expression of cilia genes across 22 primate brain areas.

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Neurometabolites are the ultimate gene products in the brain and the most precise biomolecular indicators of brain endophenotypes. Metabolomics is the only "omics" that provides a moment-to-moment "snapshot" of brain circuits' biochemical activities in response to external stimuli within the context of specific genetic variations. Although the expression levels of neurometabolites are highly dynamic, the underlying metabolic processes are tightly regulated during brain development, maturation, and aging.

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Intergenerational trauma increases lifetime susceptibility to depression and other psychiatric disorders. Whether intergenerational trauma transmission is a consequence of in-utero neurodevelopmental disruptions versus early-life mother-infant interaction is unknown. Here, we demonstrate that trauma exposure during pregnancy induces in mouse offspring social deficits and depressive-like behavior.

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Histamine H3 receptors (H3Rs) are involved in several neuropsychiatric diseases including epilepsy. Therefore, the effects of H3R antagonist E177 (5 and 10 mg/kg, intraperitoneal (i.p.

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Article Synopsis
  • Primary cilia are essential cellular structures that act as sensors for external stimuli and are critical for cell communication, with dysfunctions linked to various psychiatric disorders.
  • A study analyzed gene expression in schizophrenia, autism spectrum disorder, bipolar disorder, and major depressive disorder, finding significant dysregulation in cilia genes across all conditions, with notable overlap between disorders.
  • This research highlights the potential role of cilia in the pathology of these psychiatric disorders and suggests that targeting cilia-related proteins could lead to new treatment options.
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A novel lab-in-a-pencil graphite microfluidic sensing electrode (μFSE) was fabricated for real-time flow injection measurement of the antipsychotic drug clozapine (Clz). A simple, low-cost, and reusable μFSE was obtained by using 3D printing of a microfluidic chamber integrated with a flat pencil graphite without the need to utilize complex technologies. The μFSE has tubular geometry with 800 μm diameter, where the solution continuously flows in the holes of flat pencil graphite electrodes.

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Oxytocin regulates social behaviors and has been linked to the etiology of autism and schizophrenia. Oxytocin and another hypothalamic neuropeptide, melanin concentrating hormone (MCH), share several physiological actions such as emotion, social behavior and recognition, maternal care, sexual behavior and stress, which suggests that these two systems may interact, however, how they would do it is not known. Here, we study the interactions between the oxytocin and MCH systems in behaviors related to autism and schizophrenia.

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