Neuroscience Research Notes

Understanding drug craving: evidence from fMRI studies

2024-05-25T02:56:21+08:00

Drug craving is a major crisis experienced by active or former drug abusers. The experience is characterised by an intense desire to abuse drugs for self-pleasure and satisfaction. This desire appears to be the main culprit behind the skyrocketing relapse rate. Neuroimaging has identified neural substrates associated with drug cravings. Here, we provide a mini-review of functional magnetic resonance imaging (fMRI) studies that have examined the brain regions associated with the common types of drug abuse — heroin, methamphetamine, and cocaine. Most studies use visual cues (that is drug-related images) to elicit brain responses in reward-related pathways. Studies have also focused on comparing brain activities between active drug abusers, drug-abstinent individuals, and healthy controls. Current evidence suggests that the dorsolateral prefrontal cortex (DLPFC) is associated with heroin craving, whereas the ventral striatum and medial prefrontal cortex (mPFC) underpin methamphetamine craving. Meanwhile, the hypothalamus is responsible for cocaine cravings. Compared to active drug abusers, drug-abstinent individuals demonstrated fewer brain activations when viewing drug-related images. The relationship between brain response and drug cravings is discussed in terms of brain functions and drug types. The findings offer valuable insights into the potential role of these brain areas in drug cravings and have important implications for drug addiction treatments.

Platelets as mediators of neuropsychiatric and neurodegenerative diseases

2024-05-10T16:46:41+08:00

Numerous studies showing platelets' role in mechanisms beyond hemostasis have sparked interest in investigating all the pathways in which they may be involved. A growing body of evidence indicates that platelets play a key role in immune response. Platelets carry various membrane receptors and release many bioactive molecules that recruit and activate immune cells. Consequently, platelets have a significant immunoregulatory role in infectious, inflammatory, and degenerative diseases. Moreover, immune cells contribute to neuronal development, neural plasticity, and neuroglial activation. The interaction between platelets and immune cells reveals an additional regulatory mechanism of brain function. This review explores the relationship between platelets and the central nervous system (CNS). It highlights the role of platelets in the development of severe neurodegenerative and neuropsychiatric diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) and depression.

The types of repairs, categories of repairs, repairs in doctor-patient communication, and repair strategies from the perspective of psycholinguistics

2024-05-03T01:53:44+08:00

The nature of human spontaneous speech brings about speech errors and typical disfluencies such as hesitation, pause, silence, repetition, and repair. Recent studies in spoken dialects across many countries reported that speakers produce speech errors or unclear expressions in daily verbal communication. When speakers realize their utterances are erroneous or inappropriate, they frequently make pervasive, highly systematic, and measurable repairs in conversation. Some researchers claim that the repairs in conversation are ubiquitous. This occurrence reflects that individuals make great efforts to ensure their utterances are understandable and acceptable to the listeners. This also triggered the question of what role do speech repairs play in building mutual understanding and enhancing therapeutic relationships between doctors and patients during clinical interactions. Most of these studies have predominantly focused on first (L1) and second language (L2) acquisition, while limited studies have investigated repairs in clinical settings. Repair is a key mechanism for building mutual understanding in clinical interactions and contributes to better therapeutic relationships and treatment adherence. Doctors and patients attempt to make their utterances understandable and acceptable to attain their purposes in the clinical encounter. Nevertheless, some studies do not describe the categories of repair strategies and the trouble source, while only limited research mentioned the types of repair. This gives no insights into the specific strategies and trouble sources in the communication. This study, therefore, sets out to review the types of repairs, categories of repairs, repairs in doctor-patient communication, and repair strategies in attempting to explain the repair mechanism that works in the communication setting between doctor-patient interactions from the perspective of epistemic, pragmatics, conversation analysis, and psycholinguistics.

Cognitive performance in Mongolian patients after transient ischemic attack and the impact of vascular risk factors: a case-controlled study

2024-04-15T01:43:45+08:00

Cognitive impairment is a prevalent occurrence after a transient ischemic attack (TIA), but there is currently insufficient evidence to understand the impact of vascular risk factors (VRFs) on this event. We aimed to determine the occurrence of cognitive impairment following a TIA and to explore whether VRFs correlate with cognitive impairment. This hospital-based case-controlled study recruited patients with TIA aged 45 to 65 years without prior stroke or cognitive decline who underwent the Mini Mental State Examination (MMSE) within 3 months at the Mongolia-Japan Hospital between May and December 2023. Age (±1 year) and sex-matched controls were selected from outpatient departments. One hundred thirty-four patients (N=134) with TIA (61.2% women, mean age, 56.4±6.5 years) were included and compared with 134 controls (61.2% women, mean age, 56.1±6.4 years). Significant differences in MMSE scores were noted between the study groups, with mean scores of 26.32±2.23 for TIA patients and 27.99±1.94 for non-TIA subjects (p<0.0001). In the crude model, the presence of hypertension, a family history of myocardial infarction, hypercholesterinaemia, atrial fibrillation, and having three or more VRFs were all significantly associated with global cognitive performance on the MMSE (all p<0.05). When age, gender and education are controlled for, performance on the MMSE is uniquely accounted for by the presence of atrial fibrillation and having three or more VRFs (all p<0.05). Our results suggest that global cognitive impairment following a TIA may be linked to the number of VRFs in these individuals. This emphasises the importance of sustained management of VRFs beyond the recovery period to mitigate the risk of cognitive impairment.

Evaluating the psychometric properties of the Autism Stigma and Knowledge Questionnaire (ASK-Q) among Greek mental health professionals: an exploratory study

2024-05-28T00:49:42+08:00

Accurate knowledge about autism spectrum disorder (ASD), whether it is for children or adults, is necessary for healthcare professionals to address the increased needs of this population and decrease the disparities in the services provided. The study aims to adapt the Autism Stigma and Knowledge Questionnaire (ASK-Q) into Greek among mental health professionals (MHP), such as speech therapists, psychiatrists, and the general population (GP). The translated version was administered to 73 MHP and 140 GP according to the Scientific Advisory Committee of the Medical Outcomes Trust guidelines. Findings revealed that MHP had adequate knowledge of autism and did not endorse the stigma of autism. Statistically significant differences were indicated in ASK-Q subdomains between MHP and the GP and its four structural factors. The internal consistency was acceptable (α=0.646). The ROC analysis computed to determine the cut-off points of the ASK-Q four domains returned a result of 39.00 with a sensitivity of 0.616 and 1-specificity of 0.150. The proposed version of the ASK-Q has good psychometric properties and is valid and reliable for assessing the knowledge and stigma beliefs associated with autism among mental health professionals.

Cross-linguistic dissociations in Kannada-English bilingual persons with aphasia and alexia

2024-06-02T09:55:08+08:00

Individuals with alexia manifest reading impairments comparable to spoken language impairments. With escalating dependency on communication through texts, emails, and other social media sources, these individuals express their interest in improving written language skills as well. Alexia in bilinguals in the Indian scenario is of special interest, owing to diverse geographical, cultural, traditional, and linguistic demarcations in India. Although substantial research is reported on bilingual aphasia, evidence on bilingual alexia is scarce. The study aimed to explore the cross-linguistic dissociations in Kannada-English bilingual individuals with alexia in post-stroke survivors. Thirteen Kannada-English bilingual individuals (10 males and 3 females) with reading and language impairments post ictus, above 18 years of age were recruited. Participants were subjected to neurobehavioral linguistic and reading tasks in both Kannada and English. The performance of linguistic tasks and reading tasks were analysed for cross-linguistic distinctions, linguistics versus reading, and correlation between linguistics and reading abilities. Results revealed evident cross-linguistic dissociations, wherein participants outperformed in Kannada (L1) in both linguistics and reading domains. All performed superior in the linguistics domain compared to reading. In both languages, semantic abilities were best performed within the linguistic domains. Oral reading abilities fared poor scores relative to reading comprehension. The correlation analysis revealed strong correlation between oral reading and semantics > phonology > syntax. Reading comprehension strongly correlated to syntax > phonology > semantics. The study proved convincing linguistic influences on reading abilities in Kannada- English bilingual context. Most investigations have predominantly centred on case observations, and have often lacked thorough pre- and post-rehabilitation assessments of linguistic and reading impairments using equivalent tests in a bilingual context. This study proves to be a preliminary attempt in this context. A much larger bilingual alexia cohort would aid in substantiating the reading impairments in a variant of subgrouping of aphasia.

The effect of exclusive breastfeeding on synaptogenesis and cell survival in mouse offspring

2024-05-20T15:31:54+08:00

The first thousand days of life are critical for determining a child's cognitive development in humans. Breastfeeding may provide the nutrients needed for brain development. Cognitive function has been widely associated with neuronal turnover, driven by synaptogenesis and apoptosis. To explore this hypothesis, this study aimed to examine the effect of exclusive breastfeeding (EBF) on cognitive function and neuronal turnover in the dentate gyrus of the mice hippocampus. We conducted cognitive function assessments using the Morris Water Maze (MWM) test. We also examined neuronal apoptosis with TUNEL assay and synaptogenesis using PSD-95 antibodies. The newborn mice (mixed gender) aged 0 days were randomly divided into two groups. The first group received exclusive breastfeeding (EBF, n = 14), while the second group (MF, n = 14) received mixed breast milk and formula milk. At postnatal day 21 (PND21), the MWM test was performed, followed by an assessment of neuronal apoptosis and synaptogenesis. In the MWM test, the escape latency of the EBF group was shorter than the MF group. There was a significant increase in PSD-95 expression and a decrease in TUNEL expression in the EBF group (p < 0.001) than in the MF group. In conclusion, exclusive breastfeeding is associated with higher cognitive function. Exclusive breastfeeding affects neuronal turnover by increasing synaptogenesis and decreasing apoptosis in the dentate gyrus of the hippocampus. This has both scientific and clinical implications, pointing to nutritional practices early in life that could optimise the attainment of cognitive potential.

Frontiers in applied implication and research on combining sports science and cognitive neuroscience: Where are we heading?

2024-06-13T01:18:07+08:00