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Fulltext Congenital nasal encephalocele--a review of surgical techniques

Zamzuri I, Abdullah JM, Samsudin AR

Med J Malaysia, 2004 Oct;59(4):552-4.
PMID: 15779595

We report a case of a 6 month old baby boy who had congenital nasal encephalocele, repaired via the traditional staging procedure. The surgical techniques and procedures are described and discussed.

Matched MeSH terms: Cerebellum/abnormalities*
Fulltext Effect of early neonatal exposure to deltamethrin on the purkinje cell number in rat cerebellum

Asari MA, Abdullah MS, Abdullah S

Malays J Med Sci, 2008 Jul;15(3):14-21.
PMID: 22570585 MyJurnal

Deltamethrin is a widely used insecticide belonging to the class of pyrethroid. Although the neurotoxicity of pyrethroids including deltamethrin is well established, it is still unclear whether exposure to deltamethrin during neonatal period has any deleterious effect on the survival of the Purkinje cells in the cerebellum. In the study, we investigated the total number of Purkinje cells in experimental rats exposed to deltamethrin using a stereological method, the fractionator. Deltamethrin in a dose of 1 mg/kg/day (corresponds to 20% of LD(50) ) was administered through oral gavage to male pups from 2(nd) to 5(th) postnatal day (PND). At PND 21 the animals were sacrificed and their cerebelli were removed. The cerebelli were systematically sampled using the fractionator method and stained with cresyl fast violet. The number of the Purkinje cells was counted for each cerebellum. The results showed that there was no significant difference in the total number of Purkinje cells in the deltamethrin-treated group as compared to the control animals. This suggests that deltamethrin exposure at the current dosage during the neonatal period do not have any significant effect on the survival of the Purkinje cells in the cerebellum.

Matched MeSH terms: Cerebellum
A comparison of neurotoxicity in cerebellum produced by dermal application of chlorpyrifos in young and adult mice

Krishnan K, Mitra NK, Yee LS, Yang HM

J Neural Transm (Vienna), 2012 Mar;119(3):345-52.
PMID: 21922192 DOI: 10.1007/s00702-011-0715-5

Chlorpyrifos (CPF), an organophosphate pesticide inhibits acetylcholinesterase (AChE) and causes neuromuscular incoordination among children and elderly. The objectives of the present study were to compare the neurotoxic effects of dermal application of CPF on the cerebellum in the parameters of glial fibrillary acidic protein (GFAP) expression in young and adult mice and to correlate with the changes in acetylcholinesterase levels. Male Balb/c mice, 150 days old (adult) and 18 days old (young) were dermally applied with ½ LD(50) of CPF over the tails for 14 days. Serum AChE concentration was estimated and GFAP immunostaining was performed on sagittal paraffin sections through the vermis of cerebellum. Although reduced in both age-groups exposed to CPF, percentage of reduction in serum AChE was more in adult compared to the young. Under GFAP immunostaining, brown colour fibres and glial cells were observed in cerebellar cortex and medulla in both the experimental groups. The mean GFAP-positive glial cell count in cerebellar medulla per mm(2) of section was significantly (p cerebellum when compared with the young, when exposed to CPF.

Matched MeSH terms: Cerebellum/drug effects*; Cerebellum/metabolism
Fulltext A Hot Cross Bun sign from diffusion tensor imaging and tractography perspective

Loh KB, Rahmat K, Lim SY, Ramli N

Neurol India, 2011 Mar-Apr;59(2):266-9.
PMID: 21483130 DOI: 10.4103/0028-3886.79143

A "Hot Cross Bun" sign on T2-weighted MRI was described as a result of selective loss of myelinated transverse pontocerebellar fibers and neurons in the pontine raphe with preservation of the pontine tegmentum and corticospinal tracts (CST). However, neuropathologic studies showed contradicting results with no sparing of the CST. This is a pictorial and quantitative demonstration of the sign on diffusion tensor imaging and tractography, which provides the imaging evidence that is consistent with neuropathologic findings.

Matched MeSH terms: Cerebellum/pathology*
MR imaging of cerebral and cerebellar hypervascularity associated with status epilepticus: case report

Mukhtar AA, Ibrahim LS, Khairil AO

Nepal Med Coll J, 2007 Dec;9(4):289-91.
PMID: 18298025

A 20 year old male presented to the emergency department with generalized tonic clonic convulsions and up rolling of eye balls. He had history of seizure disorder for three years and on regular medical treatment and is compliant to medication. A non-contrast CT scan of the head was only done on 14th day of admission which showed hypodense areas in the right and left cerebellar hemisphere. MR imaging was performed four days later revealed high signal intensity in the both cerebellar hemispheres, both external capsules, both occipital and right parietal regions on fluid-attenuated inversion recovery (FLAIR). The post contrast MR imaging revealed diffuse cerebral and cerebellar hypervascularity in the similar region. This change of diffuse hypervascularity of both cerebral and cerebellar associated with seizure activity on post-contrast magnetic resonance imaging (MRI) has not been reported in any literature.

Matched MeSH terms: Cerebellum/pathology*
Mouse model of intracerebellar haemorrhage

Tijjani Salihu A, Muthuraju S, Aziz Mohamed Yusoff A, Ahmad F, Zulkifli Mustafa M, Jaafar H, et al.

Behav Brain Res, 2016 10 01;312:374-84.
PMID: 27327104 DOI: 10.1016/j.bbr.2016.06.034

The present study aimed to investigate the behavior and neuronal morphological changes in the perihaemorrhagic tissue of the mouse intracerebellar haemorrhage experimental model. Adult male Swiss albino mice were stereotactically infused with collagenase type VII (0.4U/μl of saline) unilaterally in to the cerebellum, following anaesthesia. Motor deficits were assessed using open field and composite score for evaluating the mouse model of cerebellar ataxia at 1, 3, 7, 14 and 21 days after collagenase infusion. The animals were sacrificed at the same time interval for evaluation of perihaematomal neuronal degeneration using haematoxylin and eosin staining and Annexin V-FITC/Propidium iodide assay. At the end of the study, it was found that infusion of 0.4U collagenase produces significant locomotor and ataxic deficit in the mice especially within the first week post surgery, and that this gradually improved within three weeks. Neuronal degeneration evident by cytoplasmic shrinkage and nuclear pyknosis was observed at the perihaematomal area after one day; especially at 3 and 7 days post haemorrhage. By 21 days, both the haematoma and degenerating neurons in the perihaematomal area were phagocytosed and the remaining neuronal cells around the scar tissue appeared normal. Moreover, Annexin-V/propidium iodide-positive cells were observed at the perihaematomal area at 3 and 7 days implying that the neurons likely die via apoptosis. It was concluded that a population of potentially salvageable neurons exist in the perihaematomal area after cerebellar haemorrhage throughout a wide time window that could be amenable to treatment.

Matched MeSH terms: Cerebellum/pathology*
Microstructural abnormalities found in uncinate fasciculus and superior cerebellar tracts in children with global developmental delay: a feasibility study

Ramli N, Yap A, Muridan R, Seow P, Rahmat K, Fong CY, et al.

Clin Radiol, 2020 01;75(1):77.e15-77.e22.
PMID: 31668796 DOI: 10.1016/j.crad.2019.09.134

AIM: To evaluate the microstructural abnormalities of the white matter tracts (WMT) using diffusion tensor imaging (DTI) in children with global developmental delay (GDD).
MATERIALS AND METHODS: Sixteen children with GDD underwent magnetic resonance imaging (MRI) and cross-sectional DTI. Formal developmental assessment of all GDD patients was performed using the Mullen Scales of Early Learning. An automated processing pipeline for the WMT assessment was implemented. The DTI-derived metrics of the children with GDD were compared to healthy children with normal development (ND).
RESULTS: Only two out of the 17 WMT demonstrated significant differences (p<0.05) in DTI parameters between the GDD and ND group. In the uncinate fasciculus (UF), the GDD group had lower mean values for fractional anisotropy (FA; 0.40 versus 0.44), higher values for mean diffusivity (0.96 versus 0.91×10-3 mm2/s) and radial diffusivity (0.75 versus 0.68×10-3 mm2/s) compared to the ND group. In the superior cerebellar peduncle (SCP), mean FA values were lower for the GDD group (0.38 versus 0.40). Normal myelination pattern of DTI parameters was deviated against age for GDD group for UF and SCP.
CONCLUSION: The UF and SCP WMT showed microstructural changes suggestive of compromised white matter maturation in children with GDD. The DTI metrics have potential as imaging markers for inadequate white matter maturation in GDD children.

Matched MeSH terms: Cerebellum/abnormalities*
Synthesis of α,β-Unsaturated Carbonyl-Based Compounds, Oxime and Oxime Ether Analogs as Potential Anticancer Agents for Overcoming Cancer Multidrug Resistance by Modulation of Efflux Pumps in Tumor Cells

Qin HL, Leng J, Zhang CP, Jantan I, Amjad MW, Sher M, et al.

J Med Chem, 2016 Apr 14;59(7):3549-61.
PMID: 27010345 DOI: 10.1021/acs.jmedchem.6b00276

Sixty-nine novel α,β-unsaturated carbonyl based compounds, including cyclohexanone, tetralone, oxime, and oxime ether analogs, were synthesized. The antiproliferative activity determined by using seven different human cancer cell lines provided a structure-activity relationship. Compound 8ag exhibited high antiproliferative activity against Panc-1, PaCa-2, A-549, and PC-3 cell lines, with IC50 value of 0.02 μM, comparable to the positive control Erlotinib. The ten most active antiproliferative compounds were assessed for mechanistic effects on BRAF(V600E), EGFR TK kinases, and tubulin polymerization, and were investigated in vitro to reverse efflux-mediated resistance developed by cancer cells. Compound 8af exhibited the most potent BRAF(V600E) inhibitory activity with an IC50 value of 0.9 μM. Oxime analog 7o displayed the most potent EGFR TK inhibitory activity with an IC50 of 0.07 μM, which was analogous to the positive control. Some analogs including 7f, 8af, and 8ag showed a dual role as anticancer and MDR reversal agents.

Matched MeSH terms: Cerebellum
Fulltext Interaction between vitamin E and glutathione in rat brain: Effect of chronic ethanol administration

Marcus SR, Chandrakala MV, Nadiger HA

Asia Pac J Clin Nutr, 1998 Dec;7(3/4):201-5.
PMID: 24393672

The protection against ethanol-induced lipid peroxidation is rendered by antioxidants such as vitamin E and glutathione (GSH) interacting with each other and also functioning independently. A study of the levels of GSH and activities of glutathione peroxidase (GP), glutathione reductase (GR) and glutathione transferase (GST) in the cerebral cortex (CC), cerebellum (CB) and brain stem (BS) of vitamin E-supplemented and -deficient rats subjected to ethanol administration for 30 days was carried out. Chronic ethanol administration to vitamin E-supplemented rats elevated GP, GR and GST activities in the three regions and GSH levels in the CB. Chronic ethanol administration to vitamin E-deficient rats elevated GR activity in the three regions and GP activity in the CC and CB, decreased GST activity in the CC and CB, but did not alter GSH levels compared with normal rats subjected to chronic ethanol administration. The results indicate that vitamin E helps to maintain GSH levels to combat increased peroxidation while its absence has a deleterious effect.

Matched MeSH terms: Cerebellum
Fulltext Investigating brain activation and neural efficacy during simple arithmetic addition task in quiet and in noise: an fMRI study

Ng, Sok Bee, Ahmad Nazlim Yusoff, Teng, Xin Ling, Aini Ismafairus Abd. Hamid

Jurnal Sains Kesihatan Malaysia, 2014;12(1):23-33.
MyJurnal

Knowledge about the hemodynamic model that mediates synaptic activity and measured magnetic resonance signal is essential in understanding brain activation. Neural efficacy is a hemodynamic parameter that would change the evoked hemodynamic responses. In this work, brain activation and neural efficacy of the activated brain areas during simple addition task in two different backgrounds were studied using fMRI. The objectives were to determine the activated areas during the performance of arithmetic addition in quiet (AIQ) and noisy (AIN) background and to investigate the relationship between neural efficacy and height extent of activation for the respective areas. Eighteen healthy male participants performed simple arithmetic addition in quiet and in noise. Bilateral cerebellum, superior temporal gyrus (STG), temporal pole (TP) and supplementary motor area (SMA) were significantly (p < 0.05) activated during AIQ and AIN. Left middle frontal gyrus (L-MFG), right superior frontal gyrus (R-SFG), right superior orbital gyrus (R-SOG) and bilateral insula were more active in quiet as compared to in noise while the left middle cingulate cortex (L-MCC), left amygdala (L-AMG), right temporal pole (R-TP) and left cerebellum (L-CER) were more active in noise as compared to in quiet. The t value for most of the activated regions was found to be inversely proportional to the neural efficacy. Significant (p < 0.05) negative relationship between t value and neural efficacy were found for R-STG and bilateral cerebellum during AIQ, while for AIN, similar relationships were found in R-CER, R-STG and R-TP. This study suggests that while being significantly activated, the hemodynamic responses of these brain regions could have been suppressed by the stimulus resulting in an intensity decrease with increasing neural efficacy.

Matched MeSH terms: Cerebellum
Fulltext Dandy-walker syndrome in a child at rural Kelantan, Malaysia

Low, Qin Jia, Huan, Nai Chien, Tan, Wei Lun

Borneo Journal of Medical Sciences, 2018;12(2):41-45.
MyJurnal

Dandy-Walker syndrome is a rare congenital malformation of the brain that involves the cerebellum and the fourth ventricle. It is characterised by a classical triad of hydrocephalus, cystic dilatation of the fourth ventricle and complete or partial agenesis of the vermis. Majority of cases are diagnosed during neonatal or early infantile period. In this case report, a seven-year-old boy complained of recurrent headaches for the past one year. Physical examination was unremarkable. Examination of the fundus on the same day revealed bilateral papilloedema. His subsequent computed tomography scan of the brain done at a major district hospital demonstrated features in keeping with Dandy-Walker malformation. Our case highlighted the importance of embarking on a detailed and thorough approach when dealing with a child with chronic headache, especially in rural settings where advanced medical equipment is not readily available.

Matched MeSH terms: Cerebellum
Upward transtentorial herniation of posterior fossa structures

Wang CY, Chee CP, Delilkan AE

Eur J Anaesthesiol, 1991 Nov;8(6):469-70.
PMID: 1765045
Matched MeSH terms: Cerebellum/pathology*
Thymoquinone prevents β-amyloid neurotoxicity in primary cultured cerebellar granule neurons

Ismail N, Ismail M, Mazlan M, Latiff LA, Imam MU, Iqbal S, et al.

Cell Mol Neurobiol, 2013 Nov;33(8):1159-69.
PMID: 24101432 DOI: 10.1007/s10571-013-9982-z

Thymoquinone (TQ), a bioactive constituent of Nigella sativa Linn (N. sativa) has demonstrated several neuropharmacological attributes. In the present study, the neuroprotective properties of TQ were investigated by studying its anti-apoptotic potential to diminish β-amyloid peptide 1-40 sequence (Aβ1-40)-induced neuronal cell death in primary cultured cerebellar granule neurons (CGNs). The effects of TQ against Aβ1-40-induced neurotoxicity, morphological damages, DNA condensation, the generation of reactive oxygen species, and caspase-3, -8, and -9 activation were investigated. Pretreatment of CGNs with TQ (0.1 and 1 μM) and subsequent exposure to 10 μM Aβ1-40 protected the CGNs against the neurotoxic effects of the latter. In addition, the CGNs were better preserved with intact cell bodies, extensive neurite networks, a loss of condensed chromatin and less free radical generation than those exposed to Aβ1-40 alone. TQ pretreatment inhibited Aβ1-40-induced apoptosis of CGNs via both extrinsic and intrinsic caspase pathways. Thus, the findings of this study suggest that TQ may prevent neurotoxicity and Aβ1-40-induced apoptosis. TQ is, therefore, worth studying further for its potential to reduce the risks of developing Alzheimer's disease.

Matched MeSH terms: Cerebellum/pathology*
Fulltext Review on Cross Talk between Neurotransmitters and Neuroinflammation in Striatum and Cerebellum in the Mediation of Motor Behaviour

Abg Abd Wahab DY, Gau CH, Zakaria R, Muthu Karuppan MK, A-Rahbi BS, Abdullah Z, et al.

Biomed Res Int, 2019;2019:1767203.
PMID: 31815123 DOI: 10.1155/2019/1767203

Neurological diseases particularly Alzheimer's disease (AD), Parkinson's disease (PD), stroke, and epilepsy are on the rise all around the world causing morbidity and mortality globally with a common symptom of gradual loss or impairment of motor behaviour. Striatum, which is a component of the basal ganglia, is involved in facilitating voluntary movement while the cerebellum is involved in the maintenance of balance and coordination of voluntary movements. Dopamine, serotonin, gamma-aminobutyric acid (GABA), and glutamate, to name a few, interact in regulating the excitation and inhibition of motor neurons. In another hand, interestingly, the motor loss associated with neurological diseases is possibly resulted from neuroinflammation induced by the neuroimmune system. Toll-like receptors (TLRs) are present in the central nervous system (CNS), specifically and primarily expressed in microglia and are also found on neurons and astrocytes, functioning mainly in the regulation of proinflammatory cytokine production. TLRs are always found to be associated or involved in the induction of neuroinflammation in neurodegenerative diseases. Activation of toll-like receptor 4 (TLR4) through TLR4 agonist, lipopolysaccharide (LPS), stimulation initiate a signaling cascade whereby the TLR4-LPS interaction has been found to result in physiological and behavioural changes including retardation of motor activity in the mouse model. TLR4 inhibitor TAK-242 was reflected in the reduction of the spinal cord pathology along with the motor improvement in ALS mouse. There is cross talk with neuroinflammation and neurochemicals. For example, TLR4 activation by LPS is noted to release proinflammatory cytokines, IL-1β, from microglia that subsequently suppresses GABA receptor activities at the postsynaptic site and reduces GABA synthesis at the presynaptic site. Glial glutamate transporter activities are also found to be suppressed, showing the association between TLR4 activation and the related neurotransmitters and corresponding receptors and transporters in the event of neuroinflammation. This review is helpful to understand the connection between neurotransmitter and neuroinflammation in striatum- and cerebellum-mediated motor behaviour.

Matched MeSH terms: Cerebellum/drug effects*
Fulltext Computed tomography findings in maple syrup urine disease

Ong LC, Khoo TB, Zulfiqar A, Zarida H, Ruzana A

Singapore Med J, 1998 Aug;39(8):370-2.
PMID: 9844500

Maple syrup urine disease (MSUD) is an inherited metabolic disorder characterised by a severe, usually lethal, neonatal course unless dietary intake of branched chain amino acids is restricted. We describe a patient with MSUD who had computed tomography (CT) changes of diffuse white matter hypodensity, particularly in the deep white cerebellar matter, brain stem, cerebral peduncles, thalamus and posterior limb of the internal capsule. With dietary treatment, there was neurological improvement with simultaneous disappearance of the oedema. These CT changes are typical of MSUD, hence are relevant findings in the neuroradiologic differential diagnosis of a possible metabolic disorder.

Matched MeSH terms: Cerebellum/radiography
Fulltext Therapeutic roles of natural remedies in combating hereditary ataxia: A systematic review

Phang MWL, Lew SY, Chung I, Lim WK, Lim LW, Wong KH

Chin Med, 2021 Jan 28;16(1):15.
PMID: 33509239 DOI: 10.1186/s13020-020-00414-x

BACKGROUND: Hereditary ataxia (HA) represents a group of genetically heterogeneous neurodegenerative diseases caused by dysfunction of the cerebellum or disruption of the connection between the cerebellum and other areas of the central nervous system. Phenotypic manifestation of HA includes unsteadiness of stance and gait, dysarthria, nystagmus, dysmetria and complaints of clumsiness. There are no specific treatments for HA. Management strategies provide supportive treatment to reduce symptoms.
OBJECTIVES: This systematic review aimed to identify, evaluate and summarise the published literature on the therapeutic roles of natural remedies in the treatment of HA to provide evidence for clinical practice.
METHODS: A systematic literature search was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Web of Science, PubMed and Science Direct Scopus were thoroughly searched for relevant published articles from June 2007 to July 2020.
RESULTS: Ten pre-clinical and two clinical studies were eligible for inclusion in this systematic review. We identified the therapeutic roles of medicinal plants Brassica napus, Gardenia jasminoides, Gastrodia elata, Ginkgo biloba, Glycyrrhiza inflata, Paeonia lactiflora, Pueraria lobata and Rehmannia glutinosa; herbal formulations Shaoyao Gancao Tang and Zhengan Xifeng Tang; and medicinal mushroom Hericium erinaceus in the treatment of HA. In this review, we evaluated the mode of actions contributing to their therapeutic effects, including activation of the ubiquitin-proteasome system, activation of antioxidant pathways, maintenance of intracellular calcium homeostasis and regulation of chaperones. We also briefly highlighted the integral cellular signalling pathways responsible for orchestrating the mode of actions.
CONCLUSION: We reviewed the therapeutic roles of natural remedies in improving or halting the progression of HA, which warrant further study for applications into clinical practice.

Matched MeSH terms: Cerebellum
Glutamate receptors and transporters as comparative cues to the glutamatergic circuits of the avian and mammalian brain

Islam, M.R., Muzaimi, M., Abdullah, J.M.

Orient Neuron Nexus, 2011;2(1):2-9.
MyJurnal

Glutamate is the principal excitatory neurotransmitter in the central nervous system, and plays important roles in both physiological and pathological neuronal processes. Current understanding of the exact mechanisms involved in glutamate-induced neuronal excitotoxicity, in which excessive glutamate causes neuronal dysfunction and degeneration, whether acute or chronic, remain elusive. Conditions, due to acute insults such as ischaemia and traumatic brain injury, and chronic neurodegenerative disorders such as multiple sclerosis and motor neuron disease, suffer from the lack of translational neuroprotection in clinical setting to tackle glutamate excitotoxicity despite steady growth of animal studies that revealed complex cell death pathway interactions. In addition, glutamates are also released by non-neuronal cells including astrocytes and oligodendroglia. Thus, attempts to elucidate this complexity are closely related to our understanding of the glutamatergic circuitry in the brain. Neuronal cells develop a glutamatergic system at glutamatergic synapses that utilise glutamate as an intercellular signaling molecule to characterise the output, input, and termination of this signaling. As to signal input, various kinds of glutamate receptors have been identified and characterized. Na+-dependent glutamate transporters at the plasma membrane are responsible for the signal termination through sequestration of glutamate from the synaptic cleft. The signal output systems comprise vesicular storage and subsequent exocytosis of glutamate by using vesicular glutamate transporters. Similar to the mammalian brain, the regional differences of glutamatergic neurons and glutamate receptor neurons suggest many glutamatergic projections in the avian brain, as supported by recent evidence of glutamate-related genes distribution. Glutamatergic target areas are expected to show high activity of glutamate transporters that remove released glutamate from the synaptic clefts. This review summarises and compares glutamatergic circuits in the avian and mammalian brain, particularly in the olfactory pathway, the paffial organization of glutamatergic neurons and connection with the striatum, hippocampal-septal pathway, visual and auditory pathways, and granule cell-Purkinje cell pathway in the cerebellum. Comparative appreciation of these glutamatergic circuits, particularly with the localisation and/or expression of specific subtypes of glutamate transporters, would provide the morphological basis for physiological and pharmacological designs that supplement existing animal studies of the current proposed mechanisms that underlie glutamate-induced neuronal excitotoxicity.

Matched MeSH terms: Cerebellum
Fulltext Working Memory From the Psychological and Neurosciences Perspectives: A Review

Chai WJ, Abd Hamid AI, Abdullah JM

Front Psychol, 2018;9:401.
PMID: 29636715 DOI: 10.3389/fpsyg.2018.00401

Since the concept of working memory was introduced over 50 years ago, different schools of thought have offered different definitions for working memory based on the various cognitive domains that it encompasses. The general consensus regarding working memory supports the idea that working memory is extensively involved in goal-directed behaviors in which information must be retained and manipulated to ensure successful task execution. Before the emergence of other competing models, the concept of working memory was described by the multicomponent working memory model proposed by Baddeley and Hitch. In the present article, the authors provide an overview of several working memory-relevant studies in order to harmonize the findings of working memory from the neurosciences and psychological standpoints, especially after citing evidence from past studies of healthy, aging, diseased, and/or lesioned brains. In particular, the theoretical framework behind working memory, in which the related domains that are considered to play a part in different frameworks (such as memory's capacity limit and temporary storage) are presented and discussed. From the neuroscience perspective, it has been established that working memory activates the fronto-parietal brain regions, including the prefrontal, cingulate, and parietal cortices. Recent studies have subsequently implicated the roles of subcortical regions (such as the midbrain and cerebellum) in working memory. Aging also appears to have modulatory effects on working memory; age interactions with emotion, caffeine and hormones appear to affect working memory performances at the neurobiological level. Moreover, working memory deficits are apparent in older individuals, who are susceptible to cognitive deterioration. Another younger population with working memory impairment consists of those with mental, developmental, and/or neurological disorders such as major depressive disorder and others. A less coherent and organized neural pattern has been consistently reported in these disadvantaged groups. Working memory of patients with traumatic brain injury was similarly affected and shown to have unusual neural activity (hyper- or hypoactivation) as a general observation. Decoding the underlying neural mechanisms of working memory helps support the current theoretical understandings concerning working memory, and at the same time provides insights into rehabilitation programs that target working memory impairments from neurophysiological or psychological aspects.

Matched MeSH terms: Cerebellum
Melatonin receptors: distribution in mammalian brain and their respective putative functions

Ng KY, Leong MK, Liang H, Paxinos G

Brain Struct Funct, 2017 Sep;222(7):2921-2939.
PMID: 28478550 DOI: 10.1007/s00429-017-1439-6

Melatonin, through its different receptors, has pleiotropic functions in mammalian brain. Melatonin is secreted mainly by the pineal gland and exerts its effects via receptor-mediated and non-receptor-mediated actions. With recent advancement in neuroanatomical mapping, we may now understand better the localizations of the two G protein-coupled melatonin receptors MT1 and MT2. The abundance of these melatonin receptors in respective brain regions suggests that receptor-mediated actions of melatonin might play crucial roles in the functions of central nervous system. Hence, this review aims to summarize the distribution of melatonin receptors in the brain and to discuss the putative functions of melatonin in the retina, cerebral cortex, reticular thalamic nucleus, habenula, hypothalamus, pituitary gland, periaqueductal gray, dorsal raphe nucleus, midbrain and cerebellum. Studies on melatonin receptors in the brain are important because cumulative evidence has pointed out that melatonin receptors not only play important physiological roles in sleep, anxiety, pain and circadian rhythm, but might also be involved in the pathogenesis of a number of neurodegenerative diseases including Alzheimer's disease, Parkinson's disease and Huntington's disease.

Matched MeSH terms: Cerebellum
Fulltext Functional Antagonism of Sphingosine-1-Phosphate Receptor 1 Prevents Harmaline-Induced Ultrastructural Alterations and Caspase-3 Mediated Apoptosis

Dahmardeh N, Shabani M, Basiri M, Kalantaripour TP, Asadi-Shekaari M

Malays J Med Sci, 2019 Jul;26(4):28-38.
PMID: 31496891 DOI: 10.21315/mjms2019.26.4.4

Background: There is a meaningful necessity for a targeted therapy of essential tremor (ET), as medications have not been developed specifically for ET. For nearly a century, many drugs have been applied in the treatment of tremor but the drug treatment of ET remains still unknown. Some potential therapeutic factors such fingolimod (FTY720) can be effectively used to treat ET in animals. In the present research, the effect of FTY720, the immunomodulatory sphingosine 1-phosphate (S1P) analog, on degeneration of cerebellar and olivary neurons induced by harmaline in male rats was investigated.
Methods: The animals were allotted into control dimethyl sulfoxide (DMSO), saline + harmaline [30 mg/kg, intraperitoneally, (i.p.)], harmaline + FTY720 (1 mg/kg, i.p, 1 h and 24 h before harmaline injection) groups (n = 10). The cerebellum and inferior olive nucleus (ION) were studied for neuronal degeneration using immunohistochemistry (IHC) and ultrastructural study by transmission electron microscopy (TEM) techniques.
Results: Harmaline caused neuronal cell loss, caspase-3 mediated apoptosis, astrocytosis and ultrastructural changes in cerebellar Purkinje cells and inferior olive neurons. FTY720 exhibited neuroprotective effects on cerebellar Purkinje cells and inferior olivary neurons.
Conclusion: These results suggest that FTY720 has potential efficacy for prevention of ET neurodegeneration and astrocytosis induced by harmaline in male rats.

Matched MeSH terms: Cerebellum

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