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Turkish Journal of Medical Sciences 2024This study aims to determine the possible embryotoxic effects of propofol on the cerebellum and spinal cord using fertile chicken eggs.
BACKGROUND/AIM
This study aims to determine the possible embryotoxic effects of propofol on the cerebellum and spinal cord using fertile chicken eggs.
MATERIALS AND METHODS
A total of 430 fertile eggs were divided into 5 groups: control, saline, 2.5 mg.kg, 12.5 mg.kg, and 37.5 mg.kg propofol. Injections were made immediately before incubation via the air chamber. On the 15th, 18th, and 21st day of incubation, 6 embryos from each group were evaluated. Serial paraffin sections taken from the cerebellum and spinal cord were stained with hematoxylin-eosin, Kluver-Barrera, toluidine blue, and periodic acid-Schiff's reaction. The outer granular layer and total cortex thickness were measured, and the linear density of the Purkinje cells was determined. The ratios of the substantia grisea surface area to the total surface area of the spinal cord were calculated. The transverse and longitudinal diameters of the canalis centralis were also assessed.
RESULTS
No structural malformation was observed in any embryos examined macroscopically. No significant difference was observed between the groups in terms of development and histologic organization of the cerebellum and spinal cord. However, on the 15th, 18th, and 21st day, the outer granular layer (p < 0.001 for all days) and the total cortex thickness (p < 0.01, p < 0.001, and p < 0.001, respectively) decreased significantly in different propofol dose groups in varying degrees in the cerebellum. Similarly, in the spinal cord, there were significant changes in the ratios of the substantia grisea surface area to the total surface area (p < 0.01 and p < 0.001, respectively).
CONCLUSION
It was concluded that the in-ovo-administered propofol given immediately before incubation has adverse effects on the developing cerebellum and spinal cord. Therefore, it is important for anesthesiologists always to remain vigilant when treating female patients of childbearing age.
Topics: Animals; Propofol; Cerebellum; Spinal Cord; Chick Embryo; Anesthetics, Intravenous
PubMed: 38812654
DOI: 10.55730/1300-0144.5760 -
BMC Cancer May 2024Cerebellar degeneration-related (CDR) proteins are associated with paraneoplastic cerebellar degeneration (PCD) - a rare, neurodegenerative disease caused by...
BACKGROUND
Cerebellar degeneration-related (CDR) proteins are associated with paraneoplastic cerebellar degeneration (PCD) - a rare, neurodegenerative disease caused by tumour-induced autoimmunity against neural antigens resulting in degeneration of Purkinje neurons in the cerebellum. The pathogenesis of PCD is unknown, in large part due to our limited understanding of the functions of CDR proteins. To this end, we performed an extensive, multi-omics analysis of CDR-knockout cells focusing on the CDR2L protein, to gain a deeper understanding of the properties of the CDR proteins in ovarian cancer.
METHODS
Ovarian cancer cell lines lacking either CDR1, CDR2, or CDR2L were analysed using RNA sequencing and mass spectrometry-based proteomics to assess changes to the transcriptome, proteome and secretome in the absence of these proteins.
RESULTS
For each knockout cell line, we identified sets of differentially expressed genes and proteins. CDR2L-knockout cells displayed a distinct expression profile compared to CDR1- and CDR2-knockout cells. Knockout of CDR2L caused dysregulation of genes involved in ribosome biogenesis, protein translation, and cell cycle progression, ultimately causing impaired cell proliferation in vitro. Several of these genes showed a concurrent upregulation at the transcript level and downregulation at the protein level.
CONCLUSIONS
Our study provides the first integrative multi-omics analysis of the impact of knockout of the CDR genes, providing both new insights into the biological properties of the CDR proteins in ovarian cancer, and a valuable resource for future investigations into the CDR proteins.
Topics: Humans; Cell Proliferation; Ribosomes; Female; Gene Knockout Techniques; Ovarian Neoplasms; Cell Line, Tumor; Proteomics; Nerve Tissue Proteins; Gene Expression Profiling; Transcriptome; Gene Expression Regulation, Neoplastic; Proteome; Multiomics
PubMed: 38802745
DOI: 10.1186/s12885-024-12399-z -
BioRxiv : the Preprint Server For... May 2024There is mounting evidence that the cerebellum impacts hippocampal functioning, but the impact of the cerebellum on hippocampal interneurons remains obscure. Using...
UNLABELLED
There is mounting evidence that the cerebellum impacts hippocampal functioning, but the impact of the cerebellum on hippocampal interneurons remains obscure. Using miniscopes in freely behaving animals, we find optogenetic stimulation of Purkinje cells alters the calcium activity of a large percentage of CA1 interneurons. This includes both increases and decreases in activity. Remarkably, this bidirectional impact occurs in a coordinated fashion, in line with interneurons' functional properties. Specifically, CA1 interneurons activated by cerebellar stimulation are commonly locomotion-active, while those inhibited by cerebellar stimulation are commonly rest-active interneurons. We additionally find that subsets of CA1 interneurons show altered activity during object investigations, suggesting a role in the processing of objects in space. Importantly, these neurons also show coordinated modulation by cerebellar stimulation: CA1 interneurons that are activated by cerebellar stimulation are more likely to be activated, rather than inhibited, during object investigations, while interneurons that show decreased activity during cerebellar stimulation show the opposite profile. Therefore, CA1 interneurons play a role in object processing in cerebellar impacts on the hippocampus, providing insight into previously noted altered CA1 processing of objects in space with cerebellar stimulation. We examined two different stimulation locations (IV/V Vermis; Simplex) and two different stimulation approaches (7Hz or a single 1s light pulse) - in all cases, the cerebellum induces similar coordinated CA1 interneuron changes congruent with an explorative state. Overall, our data show that the cerebellum impacts CA1 interneurons in a bidirectional and coordinated fashion, positioning them to play an important role in cerebello-hippocampal communication.
SIGNIFICANCE STATEMENT
Acute manipulation of the cerebellum can affect the activity of cells in CA1, and perturbing normal cerebellar functioning can affect hippocampal-dependent spatial processing, including the processing of objects in space. Despite the importance of interneurons on the local hippocampal circuit, it was unknown how cerebellar activation impacts CA1 inhibitory neurons. We find that stimulating the cerebellum robustly affects multiple populations of CA1 interneurons in a bidirectional, coordinated manner, according to their functional profiles during behavior, including locomotion and object investigations. Our work also provides support for a role of CA1 interneurons in spatial processing of objects, with populations of interneurons showing altered activity during object investigations.
PubMed: 38798335
DOI: 10.1101/2024.05.14.594213 -
Molecular Therapy : the Journal of the... May 2024Neuroglobin, a member of the globin superfamily, is abundant in the brain, retina, and cerebellum of mammals and localizes to mitochondria. The protein exhibits...
Neuroglobin, a member of the globin superfamily, is abundant in the brain, retina, and cerebellum of mammals and localizes to mitochondria. The protein exhibits neuroprotective capacities by participating in electron transfer, oxygen supply, and protecting against oxidative stress. Our objective was to determine whether neuroglobin overexpression can be used to treat neurological disorders. We chose Harlequin mice, which harbor a retroviral insertion in the first intron of the apoptosis-inducing factor gene resulting in the depletion of the corresponding protein essential for mitochondrial biogenesis. Consequently, Harlequin mice display degeneration of the cerebellum and suffer from progressive blindness and ataxia. Cerebellar ataxia begins in Harlequin mice at the age of 4 months and is characterized by neuronal cell disappearance, bioenergetics failure, and motor and cognitive impairments, which aggravated with aging. Mice aged 2 months received adeno-associated viral vectors harboring the coding sequence of neuroglobin or apoptosis-inducing factor in both cerebellar hemispheres. Six months later, Harlequin mice exhibited substantial improvements in motor and cognitive skills; probably linked to the preservation of respiratory chain function, Purkinje cell numbers and connectivity. Thus, without sharing functional properties with apoptosis-inducing factor, neuroglobin was efficient in reducing ataxia in Harlequin mice.
PubMed: 38796706
DOI: 10.1016/j.ymthe.2024.05.030 -
Veterinary Sciences May 2024A seven-year-old healthy female Chow Chow was referred for pregnancy monitoring. Ultrasonography was used to evaluate all pregnancy and fetus parameters, and they were...
A seven-year-old healthy female Chow Chow was referred for pregnancy monitoring. Ultrasonography was used to evaluate all pregnancy and fetus parameters, and they were found to be normal. During the examination of the 42 day pregnant bitch, an unusual mass was seen in a fetus's heart. This fetus had a cardiac frequency of 273-300 beats, while the others had heart rates of 220-240 beats. Natural vaginal birth occurred at 63 days pregnant: the first two puppies were stillborn but perfectly formed, and the other three were alive and had optimal APGAR. In one of two deceased puppies, an unusual, reddish, smooth mass occupying the space in the heart was found through necroscopy. The organ was submitted for histological examination. Histopathology, immunohistochemical, and histochemical analyses all indicated a cardiac tumor with increased Purkinje cells. This type of tumor has been described in infants, swine, bearded seals, and deer but never in fetuses and neonates of dogs. To our knowledge, this is the first such case reported in veterinary medicine.
PubMed: 38787187
DOI: 10.3390/vetsci11050216 -
Frontiers in Molecular Neuroscience 2024Functions of the cerebellar cortex, from motor learning to emotion and cognition, depend on the appropriate molecular composition at diverse synapse types. Glutamate...
Functions of the cerebellar cortex, from motor learning to emotion and cognition, depend on the appropriate molecular composition at diverse synapse types. Glutamate receptor distributions have been partially mapped using immunogold electron microscopy. However, information is lacking on the distribution of many other components, such as Shank2, a postsynaptic scaffolding protein whose cerebellar dysfunction is associated with autism spectrum disorders. Here, we used an adapted Magnified Analysis of the Proteome, an expansion microscopy approach, to map multiple glutamate receptors, scaffolding and signaling proteins at single synapse resolution in the cerebellar cortex. Multiple distinct synapse-selective distribution patterns were observed. For example, AMPA receptors were most concentrated at synapses on molecular layer interneurons and at climbing fiber synapses, Shank1 was most concentrated at parallel fiber synapses on Purkinje cells, and Shank2 at both climbing fiber and parallel fiber synapses on Purkinje cells but little on molecular layer interneurons. Our results are consistent with gene expression data but also reveal input-selective targeting within Purkinje cells. In specialized glomerular structures of the granule cell layer, AMPA receptors as well as most other synaptic components preferentially targeted to synapses. However, NMDA receptors and the synaptic GTPase activating protein SynGAP preferentially targeted to extrasynaptic sites. Thus, glomeruli may be considered integrative signaling units through which mossy fibers differentially activate synaptic AMPA and extrasynaptic NMDA receptor complexes. Furthermore, we observed NMDA receptors and SynGAP at adherens junctions, suggesting a role in structural plasticity of glomeruli. Altogether, these data contribute to mapping the cerebellar 'synaptome'.
PubMed: 38783902
DOI: 10.3389/fnmol.2024.1381534 -
ENeuro Jun 2024The Cre-lox system is an indispensable tool in neuroscience research for targeting gene deletions to specific cellular populations. Here we assess the utility of several...
The Cre-lox system is an indispensable tool in neuroscience research for targeting gene deletions to specific cellular populations. Here we assess the utility of several transgenic lines, along with a viral approach, for targeting cerebellar Purkinje cells (PCs) in mice. Using a combination of a fluorescent reporter line () to indicate -mediated recombination and a floxed Dystroglycan line ( ), we show that reporter expression does not always align precisely with loss of protein. The commonly used line exhibits a gradual mosaic pattern of recombination in PCs from Postnatal Day 7 (P7) to P14, while loss of Dag1 protein is not complete until P30. drives recombination in precursor cells that give rise to GABAergic neurons in the embryonic cerebellum, including PCs and molecular layer interneurons. However, due to its transient expression in precursors, results in stochastic loss of Dag1 protein in these neurons. , which is often described as a "pan-neuronal" line for the central nervous system, does not drive -mediated recombination in PCs. We identify a line that drives efficient and complete recombination in embryonic PCs, resulting in loss of Dag1 protein before the period of synaptogenesis. -mediated delivery of at P0 results in gradual transduction of PCs during the second postnatal week, with loss of Dag1 protein not reaching appreciable levels until P35. These results characterize several tools for targeting conditional deletions in cerebellar PCs at different developmental stages and illustrate the importance of validating the loss of protein following recombination.
Topics: Animals; Purkinje Cells; Integrases; Mice, Transgenic; Mice; Recombination, Genetic; Alleles; Gene Deletion; Cerebellum; Mice, Inbred C57BL; Transcription Factors
PubMed: 38777609
DOI: 10.1523/ENEURO.0149-24.2024 -
International Journal of Developmental... May 2024The cerebellum has a long, protracted developmental period that spans from the embryonic to postnatal periods; as a result, it is more sensitive to intrauterine and...
The cerebellum has a long, protracted developmental period that spans from the embryonic to postnatal periods; as a result, it is more sensitive to intrauterine and postnatal insults like nutritional deficiencies. Folate is crucial for foetal and early postnatal brain development; however, its effects on cerebellar growth and development are unknown. The aim of this study was to examine the effects of maternal folate intake on the histomorphology and cell density of the developing cerebellum. Twelve adult female rats (rattus norvegicus) were randomly assigned to one of four premixed diet groups: standard (2 mg/kg), folate-deficient (0 mg/kg), folate-supplemented (8 mg/kg) or folate supra-supplemented (40 mg/kg). The rats started their diets 14 days before mating and consumed them throughout pregnancy and lactation. On postnatal days 1, 7, 21 and 35, five pups from each group were sacrificed, and their brains were processed for light microscopic analysis. Histomorphology and cell density of the external granule, molecular, Purkinje and internal granule layers were obtained. The folate-deficient diet group had smaller, dysmorphic cells and significantly lower densities of external granule, molecular, Purkinje and internal granule cells. Although the folate-enriched groups had greater cell densities than the controls, the folate-supplemented group had considerably higher cell densities than the supra-supplemented group. The folate supra-supplemented group had ectopic Purkinje cells in the internal granule cell layer. These findings imply that a folate-deficient diet impairs cellular growth and reduces cell density in the cerebellar cortex. On the other hand, folate supplementation increases cell densities, but there appears to be an optimal dose of supplementation since excessive folate levels may be detrimental.
PubMed: 38773676
DOI: 10.1002/jdn.10337 -
Cell Discovery May 2024A long-standing hypothesis proposes that certain RNA(s) must exhibit structural roles in microtubule assembly. Here, we identify a long noncoding RNA (TubAR) that is...
A long-standing hypothesis proposes that certain RNA(s) must exhibit structural roles in microtubule assembly. Here, we identify a long noncoding RNA (TubAR) that is highly expressed in cerebellum and forms RNA-protein complex with TUBB4A and TUBA1A, two tubulins clinically linked to cerebellar and myelination defects. TubAR knockdown in mouse cerebellum causes loss of oligodendrocytes and Purkinje cells, demyelination, and decreased locomotor activity. Biochemically, we establish the roles of TubAR in promoting TUBB4A-TUBA1A heterodimer formation and microtubule assembly. Intriguingly, different from the hypomyelination-causing mutations, the non-hypomyelination-causing mutation TUBB4A-R2G confers gain-of-function for an RNA-independent interaction with TUBA1A. Experimental use of R2G/A mutations restores TUBB4A-TUBA1A heterodimer formation, and rescues the neuronal cell death phenotype caused by TubAR knockdown. Together, we uncover TubAR as the long-elusive structural RNA for microtubule assembly and demonstrate how TubAR mediates microtubule assembly specifically from αβ-tubulin heterodimers, which is crucial for maintenance of cerebellar myelination and activity.
PubMed: 38769343
DOI: 10.1038/s41421-024-00667-y -
European Journal of Histochemistry : EJH May 2024Previous studies on the granular layer of the cerebellar cortex have revealed a wide distribution of different subpopulations of less-known large neuron types, called... (Review)
Review
Previous studies on the granular layer of the cerebellar cortex have revealed a wide distribution of different subpopulations of less-known large neuron types, called "non-traditional large neurons", which are distributed in three different zones of the granular layer. These neuron types are mainly involved in the formation of intrinsiccircuits inside the cerebellar cortex. A subpopulation of these neuron types is represented by the synarmotic neuron, which could play a projective role within the cerebellar circuitry. The synarmotic neuron cell body map within the internal zone of the granular layer or in the subjacent white substance. Furthermore, the axon crosses the granular layer and runs in the subcortical white substance, to reenter in an adjacent granular layer, associating two cortico-cerebellar regions of the same folium or of different folia, or could project to the intrinsic cerebellar nuclei. Therefore, along with the Purkinje neuron, the traditional projective neuron type of the cerebellar cortex, the synarmotic neuron is candidate to represent the second projective neuron type of the cerebellar cortex. Studies of chemical neuroanatomy evidenced a predominant inhibitory GABAergic nature of the synarmotic neuron, suggesting that it may mediate an inhibitory GABAergic output of cerebellar cortex within cortico-cortical interconnections or in projections towards intrinsic cerebellar nuclei. On this basis, the present minireview mainly focuses on the morphofunctional and neurochemical data of the synarmotic neuron, and explores its potential involvement in some forms of cerebellar ataxias.
Topics: Cerebellar Cortex; Animals; Humans; Neurons; GABAergic Neurons
PubMed: 38766720
DOI: 10.4081/ejh.2024.3954