-
Neural Regeneration Research Jan 2024Adult neurogenesis, the process of creating new neurons, involves the coordinated division, migration, and differentiation of neural stem cells. This process is... (Review)
Review
Adult neurogenesis, the process of creating new neurons, involves the coordinated division, migration, and differentiation of neural stem cells. This process is restricted to neurogenic niches located in two distinct areas of the brain: the subgranular zone of the dentate gyrus of the hippocampus and the subventricular zone of the lateral ventricle, where new neurons are generated and then migrate to the olfactory bulb. Neurogenesis has been thought to occur only during the embryonic and early postnatal stages and to decline with age due to a continuous depletion of neural stem cells. Interestingly, recent years have seen tremendous progress in our understanding of adult brain neurogenesis, bridging the knowledge gap between embryonic and adult neurogenesis. Here, we discuss the current status of adult brain neurogenesis in light of what we know about neural stem cells. In this notion, we talk about the importance of intracellular signaling molecules in mobilizing endogenous neural stem cell proliferation. Based on the current understanding, we can declare that these molecules play a role in targeting neurogenesis in the mature brain. However, to achieve this goal, we need to avoid the undesired proliferation of neural stem cells by controlling the necessary checkpoints, which can lead to tumorigenesis and prove to be a curse instead of a blessing or hope.
PubMed: 37488837
DOI: 10.4103/1673-5374.375317 -
Phytotherapy Research : PTR Dec 2023Schizophrenia is a chronic brain disorder characterized by positive symptoms (delusions or hallucinations), negative symptoms (impaired motivation or social withdrawal),...
Schizophrenia is a chronic brain disorder characterized by positive symptoms (delusions or hallucinations), negative symptoms (impaired motivation or social withdrawal), and cognitive impairment. In the present study, we explored whether D-pinitol could ameliorate schizophrenia-like behaviors induced by MK-801, an N-methyl-D-aspartate receptor antagonist. Acoustic startle response test was conducted to evaluate the effects of D-pinitol on sensorimotor gating function. Social interaction and novel object recognition tests were employed to measure the impact of D-pinitol on social behavior and cognitive function, respectively. Additionally, we examined whether D-pinitol affects motor coordination. Western blotting was conducted to investigate the mechanism of action of D-pinitol. Single administration of D-pinitol at 30, 100, or 300 mg/kg improved the sensorimotor gating deficit induced by MK801 in the acoustic startle response test. D-Pinitol also reversed social behavior deficits and cognitive impairments induced by MK-801 without causing any motor coordination deficits. Furthermore, D-pinitol reversed increased expression levels of pNF-kB induced by MK-801 treatment and consequently increased expression levels of TNF-α and IL-6 in the prefrontal cortex. These results suggest that D-pinitol could be a potential candidate for treating sensorimotor gating deficits and cognitive impairment observed in schizophrenia by down-regulating transcription factor NF-κB and pro-inflammatory cytokines in the prefrontal cortex.
Topics: Mice; Animals; Dizocilpine Maleate; Reflex, Startle; Schizophrenia; Cognitive Dysfunction
PubMed: 37654104
DOI: 10.1002/ptr.8002 -
Journal of the American Academy of... Dec 2023Dysesthesia is an abnormal sensation in the skin that occurs in the absence of any extraordinary stimulus or other primary cutaneous disorders, excluding any delusions... (Review)
Review
Dysesthesia is an abnormal sensation in the skin that occurs in the absence of any extraordinary stimulus or other primary cutaneous disorders, excluding any delusions or tactile hallucinations. Clinicians have characterized dysesthesias to include sensations such as burning, tingling, pruritus, allodynia, hyperesthesia, or anesthesia. The etiology and pathogenesis of various generalized dysesthesias is largely unknown, though many dysesthesias have been associated with systemic pathologies including malignancy, infection, autoimmune disorders, and neuropathies. Dermatologists are often the first-line clinicians for patients presenting with such cutaneous findings, thus it is crucial for these physicians to be able to methodically work-up generalized dysesthesias to build a working differential diagnosis, follow up with key labs and/or imaging, and offer patients evidence-based treatment to relieve their symptoms. This broad literature review is an attempt to centralize key studies, cases, and series to help guide dermatologists in their assessment and evaluation of complaints of abnormal cutaneous sensations.
Topics: Humans; Paresthesia; Skin; Pruritus; Peripheral Nervous System Diseases; Skin Diseases
PubMed: 37517675
DOI: 10.1016/j.jaad.2023.06.063 -
Journal of Psychiatric Research Dec 2023Transcranial alternating current stimulation (tACS) is an innovative noninvasive technique in brain stimulation that involves applying a low-intensity electrical current... (Review)
Review
BACKGROUND
Transcranial alternating current stimulation (tACS) is an innovative noninvasive technique in brain stimulation that involves applying a low-intensity electrical current to the scalp. And increasing evidence has revealed its potential in schizophrenia treatment.
OBJECTIVE
This systematic review aimed to evaluate the efficacy of tACS as a novel neurostimulation technique for improving cognitive impairment and alleviating psychotic symptoms in schizophrenia. Additionally, this review attempted to explore the impact of stimulation parameters on the effectiveness of tACS treatment.
METHODS
A systematic literature search was conducted across five databases, including Web of Science, Embase, PubMed, CENTRAL, and PsycINFO, to identify studies investigating the use of tACS in schizophrenia. Only studies that involved the experimental use of tACS in patients with schizophrenia were included in this review.
RESULTS
Nineteen studies were included in this review. The most frequently used current intensities were 2 mA and 1 mA, and the most commonly used frequencies were alpha (10 Hz), theta (4.5 Hz and 6 Hz), and gamma (40 Hz). Some studies showed that tACS may have a potential therapeutic effect by improving cognitive functions in various cognitive domains and/or ameliorating negative symptoms, hallucinations, and delusions in patients with schizophrenia, while others showed no significant change. These studies also implicated that tACS treatment is safe and well tolerated.
CONCLUSIONS
Overall, this systematic review suggests that tACS has promise as a novel, effective, and adjunctive treatment approach for treating schizophrenia. Future research is needed to determine the optimal parameters of tACS for treating this complex disorder.
Topics: Humans; Schizophrenia; Transcranial Direct Current Stimulation; Hallucinations; Cognition
PubMed: 37897837
DOI: 10.1016/j.jpsychires.2023.10.021 -
Cureus Sep 2023Schizophrenia is characterized by psychotic symptoms such as delusions, hallucinations, and disorganized thinking and speech. Patients suffering from schizophrenia...
INTRODUCTION
Schizophrenia is characterized by psychotic symptoms such as delusions, hallucinations, and disorganized thinking and speech. Patients suffering from schizophrenia incited by these delusions react violently in response to real or imagined threats; this engages them in violent behaviours and thus poses a threat. Sparse data are available for patients from India with regard to schizophrenia patients acting on their delusions. The aim of this study was to assess the prevalence of delusional action in patients suffering from schizophrenia and to identify the phenomenological characteristics of those delusions which are associated with action.
MATERIAL METHODS
This study was conducted on patients with a diagnosis of schizophrenia admitted to the indoor patient department (IPD) of the Department of Psychiatry, K.D. Medical College, Hospital & Research Centre, Mathura, India, during the period of February 2022 to July 2022. A semi-structured, semi-open-ended questionnaire was used for interviewing patients regarding demographics, the course of illness, past medical illness, the family history of psychiatric disturbances, and substance use. The study tool used for delusion was the Maudsley Assessment of Delusions Schedule (MADS).
RESULTS
Out of 56 selected subjects, 34 acted on delusion and out of these, 19 were male and 15 female. In our study gender did not play any significant role in acting on delusion. Literacy and nuclear living households played a significant role in influencing delusion-driven behaviours, while the distinction between urban and rural living, though noteworthy, fell just short of achieving statistical significance. An emotional state like anger was significantly important to the patient's acting on delusion, which led to violent behaviour or self-harm.
CONCLUSION
Positive responses are more likely to be associated with leading action on delusion as compared to negative responses, which were also associated with action on delusion; for example, anger was significantly important in the patient's acting on delusion, which led to violent behaviour or self-harm.
PubMed: 37846265
DOI: 10.7759/cureus.45268 -
Psychological Medicine Oct 2023Successful leaders are at risk of developing exaggerated pride, contempt for others, and a diminished sense of reality. The ancient Greeks feared this syndrome and...
Successful leaders are at risk of developing exaggerated pride, contempt for others, and a diminished sense of reality. The ancient Greeks feared this syndrome and called it hubris. Although certain contemporaneous leaders show signs of hubris and pose a great danger, the hubris syndrome does not yet figure in our classification systems. The purpose of this paper is to examine several aspects of its validity, including clinical description, laboratory study, and exclusion of other disorders. Firstly, a substantial body of evidence indicates that the hubris syndrome may develop after a person has held substantial power for a considerable amount of time. Thus, the syndrome differs from a personality disorder with its characteristic onset in late adolescence or early adulthood. It is proposed, therefore, that the syndrome is a non-organic personality change after gaining substantial power or achieving overwhelming success, characterized by the emergence or marked increase of pathological personality traits within the domains of dissociality and disinhibition. Within the domain of dissociality, grandiosity is an obligatory trait. Secondly, with reference to laboratory study, recent evidence suggests that machine learning algorithms have the ability to differentiate hubristic from non-hubristic speech patterns. Thirdly, the exclusion of other disorders is difficult, because individuals with the hubris syndrome do not collaborate in any investigation. Some suggestions are made to overcome this problem. In conclusion, there is sufficient reason to further examine the validity of the hubris syndrome and to consider it for inclusion in our classification systems.
Topics: Adolescent; Humans; Adult; Algorithms; Delusions; Emotions; Fear; Machine Learning; Syndrome
PubMed: 37679027
DOI: 10.1017/S0033291723002672 -
International Journal of Molecular... Jul 2023Glutamate -methyl-D-aspartate receptor (NMDAR) hypofunction has been proposed to underlie schizophrenia symptoms. This theory arose from the observation that... (Review)
Review
Glutamate -methyl-D-aspartate receptor (NMDAR) hypofunction has been proposed to underlie schizophrenia symptoms. This theory arose from the observation that administration of NMDAR antagonists, which are compounds that inhibit NMDAR activity, reproduces behavioural and molecular schizophrenia-like phenotypes, including hallucinations, delusions and cognitive impairments in healthy humans and animal models. However, the role of specific NMDAR subunits in these schizophrenia-relevant phenotypes is largely unknown. Mounting evidence implicates the GluN2D subunit of NMDAR in some of these symptoms and pathology. Firstly, genetic and post-mortem studies show changes in the GluN2D subunit in people with schizophrenia. Secondly, the psychosis-inducing effects of NMDAR antagonists are blunted in GluN2D-knockout mice, suggesting that the GluN2D subunit mediates NMDAR-antagonist-induced psychotomimetic effects. Thirdly, in the mature brain, the GluN2D subunit is relatively enriched in parvalbumin (PV)-containing interneurons, a cell type hypothesized to underlie the cognitive symptoms of schizophrenia. Lastly, the GluN2D subunit is widely and abundantly expressed early in development, which could be of importance considering schizophrenia is a disorder that has its origins in early neurodevelopment. The limitations of currently available therapies warrant further research into novel therapeutic targets such as the GluN2D subunit, which may help us better understand underlying disease mechanisms and develop novel and more effective treatment options.
Topics: Animals; Humans; Mice; Brain; Interneurons; Mice, Knockout; Receptors, N-Methyl-D-Aspartate; Schizophrenia
PubMed: 37511595
DOI: 10.3390/ijms241411835 -
Scientific Reports Apr 2024Hallucinations and delusions can be symptoms of psychiatric illness, but more often—though less commonly known—are actually part of a healthy range of experiences...
Hallucinations and delusions can be symptoms of psychiatric illness, but more often—though less commonly known—are actually part of a healthy range of experiences found throughout the general population. The studies in this Special Collection paint a picture of the wide range of hallucinatory and delusional experiences across diverse populations, as well as comparative perspectives between clinical and non-clinical samples. In this editorial, I make three related points that are exemplified in the articles published here. First, that hallucinations and delusions are part of a normal distribution of human diversity; their mere presence does not indicate psychosis or psychiatric illness. Second, that the ubiquity of hallucinatory and delusional experiences across clinical and non-clinical populations suggests common cognitive and neural mechanisms. Finally, despite these commonalities, it is important to understand the difference between psychiatric symptoms and healthy experience. In summary, I conclude that it is important to investigate both common mechanisms and distinguishing factors to comprehensively elucidate these oft-misunderstood experiences. This Special Collection provides a showcase of the cutting-edge research that encompasses these objectives.
Topics: Humans; Delusions; Hallucinations; Psychotic Disorders; Forecasting
PubMed: 38600126
DOI: 10.1038/s41598-024-57472-6 -
The American Journal of Geriatric... Aug 2023Behavioral and psychological symptoms of dementia (BPSD) profiles vary depending on etiology in patients with mild-to-moderate BPSD. It is not known if similar...
OBJECTIVE
Behavioral and psychological symptoms of dementia (BPSD) profiles vary depending on etiology in patients with mild-to-moderate BPSD. It is not known if similar differences exist in patients with severe BPSD.
METHODS
We analyzed data collected at baseline in 398 patients with severe BPSD (NPI ≥ 32) and defined diagnosis of dementia (Alzheimer's disease [AD] 297; frontotemporal dementia [FTD] 39; Lewy body disease/Parkinsonian dementia [LBD/PD] 31; and vascular dementia [VD] 31) included in the European multicenter cohort RECAGE.
RESULTS
Mean total NPI was 52.11 (18.55). LBD/PD patients demonstrated more hallucinations, more anxiety and more delusions than patients with other dementia. FTD patients had less delusions and more disinhibition than patients with other neurodegenerative disorders. These profiles overlapped partially with those reported in the literature in patients with less severe symptoms.
CONCLUSION
Patients with severe BPSD display different and specific profiles of neuropsychiatric symptoms depending on dementia etiology.
Topics: Humans; Frontotemporal Dementia; Psychiatric Status Rating Scales; Alzheimer Disease; Lewy Body Disease; Dementia, Vascular
PubMed: 37183097
DOI: 10.1016/j.jagp.2023.03.014 -
BMC Neurology Mar 2024Neuropsychiatric symptoms and delusions are highly prevalent among people with dementia. However, multiple roots of neurobiological bases and shared neural basis of...
BACKGROUND
Neuropsychiatric symptoms and delusions are highly prevalent among people with dementia. However, multiple roots of neurobiological bases and shared neural basis of delusion and cognitive function remain to be characterized. By utilizing a fine-grained multivariable approach, we investigated distinct neuroanatomical correlates of delusion symptoms across a large population of dementing illnesses.
METHODS
In this study, 750 older adults with mild cognitive impairment and Alzheimer's disease completed brain structural imaging and neuropsychological assessment. We utilized principal component analysis followed by varimax rotation to identify the distinct multivariate correlates of cortical thinning patterns. Five of the cognitive domains were assessed whether the general cognitive abilities mediate the association between cortical thickness and delusion.
RESULTS
The result showed that distributed thickness patterns of temporal and ventral insular cortex (component 2), inferior and lateral prefrontal cortex (component 1), and somatosensory-visual cortex (component 5) showed negative correlations with delusions. Subsequent mediation analysis showed that component 1 and 2, which comprises inferior frontal, anterior insula, and superior temporal regional thickness accounted for delusion largely through lower cognitive functions. Specifically, executive control function assessed with the Trail Making Test mediated the relationship between two cortical thickness patterns and delusions.
DISCUSSION
Our findings suggest that multiple distinct subsets of brain regions underlie the delusions among older adults with cognitive impairment. Moreover, a neural loss may affect the occurrence of delusion in dementia largely due to impaired general cognitive abilities.
Topics: Humans; Aged; Alzheimer Disease; Delusions; Cognitive Dysfunction; Cognition; Brain
PubMed: 38448803
DOI: 10.1186/s12883-024-03568-5