Publications by authors named "Kwok Tung Lu"

Juvenile traumatic experiences can lead to adult cognitive impairments, including learning deficits and increased anxiety risk. Dysfunction of the hippocampus is crucial in stress-induced behavioral disorders, and recent evidence suggests that disrupted chloride homeostasis through the chloride transporter NKCC1 may alter GABAergic signaling and contribute to neuropathology. This study investigates the role of NKCC1 in long-term hippocampal dysfunction induced by juvenile immobilization (J_IMO).

View Article and Find Full Text PDF

Traumatic brain injury (TBI) is a major public health problem. Here, we developed a novel model of non-invasive TBI induced by laser irradiation in the telencephalon of adult zebrafish (Danio rerio) and assessed their behavior and neuromorphology to validate the model and evaluate potential targets for neuroreparative treatment. Overall, TBI induced hypolocomotion and anxiety-like behavior in the novel tank test, strikingly recapitulating responses in mammalian TBI models, hence supporting the face validity of our model.

View Article and Find Full Text PDF

Neuropathic pain indicates pain caused by damage to the somatosensory system and is difficult to manage and treat. A new treatment strategy urgently needs to be developed. Both autophagy and apoptosis are critical adaptive mechanisms when neurons encounter stress or damage.

View Article and Find Full Text PDF
Article Synopsis
  • Traumatic brain injury (TBI), especially mild TBI in juveniles (mTBI-J), can lead to long-term effects such as depression and other mental disorders, as studied in young male rats.
  • While physical brain damage was minimal, mTBI-J subjects displayed significant depression-like behaviors, indicated by increased immobility in the forced swimming test and decreased sucrose preference.
  • The study found reduced levels of brain-derived neurotrophic factor (BDNF) in the hippocampus of mTBI-J rats, suggesting a link between this protein and the observed behavioral changes, with potential therapeutic effects noted from a TrkB agonist treatment.
View Article and Find Full Text PDF

Our previous studies have shown that early systemic granulocyte colony-stimulating factor (G-CSF) treatment can attenuate neuropathic pain in rats with chronic constriction injury (CCI) by modulating expression of different proinflammatory cytokines, microRNAs, and proteins. Besides the modulation of inflammatory mediators' expression, previous studies have also reported that G-CSF can modulate autophagic and apoptotic activity. Furthermore, both autophagy and apoptosis play important roles in chronic pain modulation.

View Article and Find Full Text PDF
Article Synopsis
  • Previous studies indicate that granulocyte-colony stimulating factor (GCSF) can reduce neuropathic pain by influencing microRNA levels and cytokine activity.
  • In a controlled experiment with rats experiencing nerve injury, GCSF treatment significantly upregulated microRNA-122 expression, which was previously downregulated due to the injury.
  • GCSF treatment also led to lower levels of MCP-1—a cytokine associated with pain development—suggesting that increased microRNA-122 may help mitigate neuropathic pain by regulating specific inflammatory pathways.
View Article and Find Full Text PDF

Previous studies showed that neonatal dexamethasone treatment (NDT) transiently impaired hippocampal function in male rats. Hippocampal estrogen receptors (ERs) participate in avoidance learning. As previous studies focused on males only, this study was aimed to investigate the NDT effects on the hippocampal function of female rats.

View Article and Find Full Text PDF

Background And Purpose: Bumetanide has anxiolytic effects in rat models of conditioned fear. As a loop diuretic, bumetanide blocks cation-chloride co-transport and this property may allow bumetanide to act as an anxiolytic by modulating GABAergic synaptic transmission in the CNS. Its potential for the treatment of anxiety disorders deserves further investigation.

View Article and Find Full Text PDF

This study was aimed to evaluate the synaptic plasticity in projections from the dorsal lateral region (Dl) to the bilateral dorsal medial region (Dm) of the zebrafish telencephalon. The results showed that unilateral electrical stimulation of the Dl evokes a negative field potential (FP) in both the contralateral and ipsilateral side of the Dm. We tested synaptic plasticity, including high-frequency stimulation-induced LTP (HFS-LTP) and low-frequency stimulation-induced LTD (LFS-LTD).

View Article and Find Full Text PDF

Fragile X syndrome (FXS) is a generally hereditary form of human mental retardation that is caused by triplet repeat expansion (CGG) mutation in fragile X mental retardation 1 (fmr1) gene promoter and that results in the absence of the fragile X mental retardation protein (FMRP) expression. The common symptoms of FXS patients include learning disabilities, anxiety, autistic behaviors, as well as other behavioral abnormalities. Our previous results demonstrated the behavioral abnormalities in fmr1 knockout (KO) zebrafish such as fear memory impairment and autism-like behavior.

View Article and Find Full Text PDF

Na -K -2Cl co-transporter (NKCC1) plays an important role in traumatic brain injury (TBI)-induced brain edema via the MAPK cascade. The transient receptor potential vanilloid type 4 (TRPV4) channel participates in neurogenic inflammation, pain transmission, and edema. In this study, we investigated the relationship between NKCC1 and TRPV4 and the related signaling pathways in TBI-induced brain edema and neuronal damage.

View Article and Find Full Text PDF

Several studies have shown that the mu opioid receptor (MOR) located in the peripheral nerves can be activated after nerve injury and that it attenuates peripheral nociceptive signals to the spinal dorsal horn. Various cytokines and phosphorylated-p38 (p-p38) activation in the dorsal horn also play an important role in neuropathic pain development. Granulocyte-colony stimulating factor (GCSF) is a growth factor that can stimulate granulocyte formation and has been shown to exert an analgesic effect on neuropathic pain through recruiting opioid-containing leukocytes to the injured nerve.

View Article and Find Full Text PDF

Rationale: The involvement of glutamate in fear extinction is perhaps the most promising in terms of facilitating clinical interventions for posttraumatic stress disorder (PTSD). This study was aimed at elucidating the possible role of zif268 on the D-cycloserine (DCS) facilitation effect on extinction.

Objective: We investigated the association between zif268 and the extinction of conditioned fear by using antisense oligodeoxynucleotide (ODN) of zif268 and the fear-potentiated startle paradigm.

View Article and Find Full Text PDF

The loop diuretic bumetanide (Bumex) is thought to have antiepileptic properties via modulate GABAA mediated signaling through their antagonism of cation-chloride cotransporters. Given that loop diuretics may act as antiepileptic drugs that modulate GABAergic signaling, we sought to investigate whether they also affect hippocampal function. The current study was performed to evaluate the possible role of NKCC1 on the hippocampal function.

View Article and Find Full Text PDF

Traumatic brain injury (TBI) is one of the most prevalent causes of worldwide mortality and morbidity. We previously had evidenced that TBI induced Na-K-2Cl co-transporter (NKCC1) upregulation in hippocampus. Here, we aim to investigate the role of NKCC1 in TBI-induced neurogenesis and the detailed mechanisms.

View Article and Find Full Text PDF

Synthetic glucocorticoid dexamethasone (DEX) is frequently used as a therapeutic agent to lessen the morbidity of chronic lung disease in premature infants. Previous studies suggested that neonatal DEX treatment altered brain development and cognitive function. It has been recognized that the amygdala is involved in emotional processes and also a critical site of neuronal plasticity for fear conditioning.

View Article and Find Full Text PDF

Fragile X syndrome (FXS) is the most frequent inherited form of human mental retardation. It is characterized by cognitive impairment and physical and behavioral problems and is caused by the silencing of fmr1 transcription and the absence of the fmr1 protein (FMRP). Recently, animal models of FXS have greatly facilitated the investigation of the molecular and cellular mechanisms of this loss-of-function disorder.

View Article and Find Full Text PDF

Recent studies have shown that opioid treatment can reduce pro-inflammatory cytokine production and counteract various neuropathic pain syndromes. Granulocyte colony-stimulating factor (G-CSF) can promote immune cell differentiation by increasing leukocytes (mainly opioid-containing polymorphonuclear (PMN) cells), suggesting a potential beneficial role in treating chronic pain. This study shows the effectiveness of exogenous G-CSF treatment (200 µg/kg) for alleviating thermal hyperalgesia and mechanical allodynia in rats with chronic constriction injury (CCI), during post-operative days 1-25, compared to that of vehicle treatment.

View Article and Find Full Text PDF

Background: Nogo-A is a member of the reticulon family of membrane-associated proteins and plays an important role in axonal remodeling. The present study aimed to investigate alterations in Nogo-A expression following traumatic brain injury (TBI)-induced inflammation and neuronal damage.

Methods: A weight-drop device was used to deliver a standard traumatic impact to rats.

View Article and Find Full Text PDF

In ray-finned fishes, the lateral (Dl) and medial (Dm) division of the dorsal telencephalon are important in learning and memory formation. Tract-tracing studies revealed that neural connections are formed between these regions via afferent Dl fibers projecting to the Dm. However, research analyzing Dl-Dm synaptic transmission is scant.

View Article and Find Full Text PDF

Alzheimer disease (AD) is an age-dependent neurodegenerative disease characterized by the formation of β-amyloid (Aβ)-containing senile plaque. The disease could be induced by the administration of Aβ peptide, which was also known to upregulate inducible nitric oxide synthase (iNOS) and stimulate neuronal apoptosis. The present study is aimed to elucidate the cellular effect of resveratrol, a natural phytoestrogen with neuroprotective activities, on Aβ-induced hippocampal neuron loss and memory impairment.

View Article and Find Full Text PDF

N-Methyl-D-aspartate (NMDA) receptors are implicated in a wide range of complex behavioral functions, including cognitive activity. Numerous studies have shown that using the repetitive administration of a noncompetitive NMDA receptor antagonist, MK-801, induces amnesia in rodents. In this study, the effect of a subchronic MK-801 treatment on the cognitive function of zebrafish was evaluated using a novel inhibitory avoidance task.

View Article and Find Full Text PDF

Drugs in clinical use with indole structure exhibit side effects. Therefore, to search for indole compounds with more efficacy and less side effect for cancer therapy, we developed a novel indole compound SK228 and examined its effects and mechanisms on antitumor growth and invasion inhibition in cell and tumor xenografts in nude mice models. SK228 significantly inhibited growth of different lung and esophageal cancer cell lines at sub-micromolar range, but not normal lung cells.

View Article and Find Full Text PDF

Rationale: Ginkgo biloba extract, EGb761, is widely used as herbal supplements throughout Western society. It has been used in the treatment of various common geriatric complaints including short-term memory loss. Our previous study has shown that acute systemic administration of EGb761 enhanced extinction of fear-potentiated startle (FPS) in rats.

View Article and Find Full Text PDF

Background: 3-Indole inhibits lung cancer growth by apoptosis. Here, the growth inhibition mechanism besides apoptosis was further characterized.

Materials And Methods: The Comet assay was used to examine 3-indole-induced DNA damage.

View Article and Find Full Text PDF