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Current Biology : CB Jan 2024Oxytocin has long been thought to play a substantial role in social behaviors, such as social attachment and parenting behavior. However, how oxytocin neurons respond to...
Oxytocin has long been thought to play a substantial role in social behaviors, such as social attachment and parenting behavior. However, how oxytocin neurons respond to social and non-social stimuli is largely unknown, especially in high temporal resolution. Here, we recorded the in vivo real-time responses of oxytocin neurons in the paraventricular nucleus of the hypothalamus (PVN) in freely behaving mice. Our results revealed that oxytocin neurons were activated more significantly by stressors than social stimuli. The activation of oxytocin neurons was precisely correlated with struggling behavior during stress. Furthermore, we found that oxytocin mediated stress-induced social memory impairment. Our results reveal an important role of PVN oxytocin neurons in stress-induced social amnesia.
Topics: Mice; Animals; Oxytocin; Hypothalamus; Paraventricular Hypothalamic Nucleus; Neurons; Receptors, Oxytocin; Memory Disorders
PubMed: 38103551
DOI: 10.1016/j.cub.2023.11.037 -
Brain Sciences Aug 2023Pesticides are chemicals used in agricultural fields for the prevention or destruction of pests. Inappropriate use of these substances, as well as handling them without... (Review)
Review
Pesticides are chemicals used in agricultural fields for the prevention or destruction of pests. Inappropriate use of these substances, as well as handling them without using personal protective equipment, may result in serious health problems such as neurodegenerative diseases and mental disorders. Previous studies have demonstrated the adverse effects of pesticides on brain function. However, some researchers have associated pesticide poisoning with the development of disorders such as dissociative amnesia, multiple personality disorders, and depersonalization disorder. The objective of this work was to perform a bibliographic review of the relationship between pesticide poisoning and the development of dissociative disorders. Previous studies suggest that the duration of pesticide exposure is a major determinant in the development of dissociative diseases and disorders. The information obtained in this review suggests that there is no specific relationship between dissociative disorders and pesticide poisoning. However, these results point to associating the most representative symptoms of dissociative disorder (such as amnesia and memory loss) with pesticide exposure. Based on the bibliographic search, possible mechanisms of action were suggested in an attempt to explain a possible association between exposure to pesticides and the appearance of dissociative disorders.
PubMed: 37626550
DOI: 10.3390/brainsci13081194 -
Cureus Sep 2023Kluver-Bucy Syndrome (KBS) is a rare neuropsychiatric disorder characterized by hyperorality, hypersexuality, bulimia, visual agnosia, and amnesia due to lesions... (Review)
Review
Kluver-Bucy Syndrome (KBS) is a rare neuropsychiatric disorder characterized by hyperorality, hypersexuality, bulimia, visual agnosia, and amnesia due to lesions affecting bilateral temporal lobes. It is attributed to a multitude of causes, including stroke, herpes simplex encephalitis, Alzheimer's disease, and head trauma. Current treatments for KBS include symptomatic management with antipsychotics, mood stabilizers, carbamazepine, and selective serotonin reuptake inhibitors. The bibliometric analysis was done to reflect the relevance and understanding of KBS in recent literature. The SCOPUS database was utilized to conduct a search for all articles with the terms "Kluver-Bucy" and "Kluver Bucy" from January 1, 1955 (the first available articles from the search) to February 1, 2023. The parameters included in this analysis were article title, citation numbers, citations per year, authors, institutions, publishing journals, country of origin, Source Normalized Impact per Paper, and Scopus CiteScore. Since 1937, when Kluver-Bucy Syndrome was first defined, the publications on KBS have steadily increased, with up to six publications a year in 2002. The most common institutions were SUNY Upstate Medical University, VA Medical Center, and the State University of New York (SUNY) System. Seven of these papers were published in . Almost 75% of the articles were published in journals of medicine and neuroscience. This is the first bibliometric analysis to evaluate the most influential publications about Kluver-Bucy Syndrome. A majority of the research is case-based and there is a dearth of clinical trials to identify the exact pathophysiology and physiotherapy management, possibly owing to the rarity of the disease. Our research suggests that there may be a significant overlap between Sanfilippo syndrome and KBS, suggesting that refined guidelines for establishing diagnosis may be required for children. Our study could bring a renewed interest in this field and lead to additional research focused on understanding the pathophysiology of KBS in order to promote the development of novel diagnostics and treatment.
PubMed: 37854727
DOI: 10.7759/cureus.45382 -
Alzheimer's & Dementia : the Journal of... Jan 2024Anesthesia often exacerbates memory recall difficulties in individuals with Alzheimer's disease (AD), but the underlying mechanisms remain unclear.
INTRODUCTION
Anesthesia often exacerbates memory recall difficulties in individuals with Alzheimer's disease (AD), but the underlying mechanisms remain unclear.
METHODS
We used in vivo Ca imaging, viral-based circuit tracing, and chemogenetic approaches to investigate anesthesia-induced remote memory impairment in mouse models of presymptomatic AD.
RESULTS
Our study identified pyramidal neuron hyperactivity in the anterior cingulate cortex (ACC) as a significant contributor to anesthesia-induced remote memory impairment. This ACC hyperactivation arises from the disinhibition of local inhibitory circuits and increased excitatory inputs from the hippocampal CA1 region. Inhibiting hyperactivity in the CA1-ACC circuit improved memory recall after anesthesia. Moreover, anesthesia led to increased tau phosphorylation in the hippocampus, and inhibiting this hyperphosphorylation prevented ACC hyperactivity and subsequent memory impairment.
DISCUSSION
Hippocampal-cortical hyperactivity plays a role in anesthesia-induced remote memory impairment. Targeting tau hyperphosphorylation shows promise as a therapeutic strategy to mitigate anesthesia-induced neural network dysfunction and retrograde amnesia in AD.
Topics: Mice; Animals; Alzheimer Disease; Hippocampus; Memory; Memory, Long-Term; Memory Disorders; Anesthesia
PubMed: 37695022
DOI: 10.1002/alz.13464 -
Bio Systems Jun 2024A thermodynamic model for memory formation is proposed. Key points include: 1) Any thought or consciousness corresponds to a thermodynamic system of nerve cells. 2) The...
A thermodynamic model for memory formation is proposed. Key points include: 1) Any thought or consciousness corresponds to a thermodynamic system of nerve cells. 2) The system concept of nerve cells can only be described by thermodynamics of condensed matter. 3) The memory structure is logically associated with the system structure or the normal structure of biology. 4) The development of our thoughts is processed irreversibly, and numerous states or thoughts can be generated. 5) Memory formation results from the reorganization and change of cellular structures (or memory structures), which are related to nerve cell skeleton and membrane. Their alteration can change the excitability of nerve cells and the pathway of neural impulse conduction. 6) Amnesia results from the loss of thermodynamic stability of the memory structure, which can be achieved by different ways. Some related phenomena and facts are discussed. The analysis shows that thermodynamics can account for the basic properties of memory.
PubMed: 38866100
DOI: 10.1016/j.biosystems.2024.105247 -
The Journal of Neuroscience : the... Sep 2023A well orchestrated coupling hierarchy of slow waves and spindles during slow-wave sleep supports memory consolidation. In old age, the duration of slow-wave sleep and...
A well orchestrated coupling hierarchy of slow waves and spindles during slow-wave sleep supports memory consolidation. In old age, the duration of slow-wave sleep and the number of coupling events decrease. The coupling hierarchy deteriorates, predicting memory loss and brain atrophy. Here, we investigate the dynamics of this physiological change in slow wave-spindle coupling in a frontocentral electroencephalography position in a large sample ( = 340; 237 females, 103 males) spanning most of the human life span (age range, 15-83 years). We find that, instead of changing abruptly, spindles gradually shift from being driven by slow waves to driving slow waves with age, reversing the coupling hierarchy typically seen in younger brains. Reversal was stronger the lower the slow-wave frequency, and starts around midlife (age range, ∼40-48 years), with an established reversed hierarchy between 56 and 83 years of age. Notably, coupling strength remains unaffected by age. In older adults, deteriorating slow wave-spindle coupling, measured using the phase slope index (PSI) and the number of coupling events, is associated with blood plasma glial fibrillary acidic protein levels, a marker for astrocyte activation. Data-driven models suggest that decreased sleep time and higher age lead to fewer coupling events, paralleled by increased astrocyte activation. Counterintuitively, astrocyte activation is associated with a backshift of the coupling hierarchy (PSI) toward a "younger" status along with increased coupling occurrence and strength, potentially suggesting compensatory processes. As the changes in coupling hierarchy occur gradually starting at midlife, we suggest there exists a sizable window of opportunity for early interventions to counteract undesirable trajectories associated with neurodegeneration. Evidence accumulates that sleep disturbances and cognitive decline are bidirectionally and causally linked, forming a vicious cycle. Improving sleep quality could break this cycle. One marker for sleep quality is a clear hierarchical structure of sleep oscillations. Previous studies showed that sleep oscillations decouple in old age. Here, we show that, rather, the hierarchical structure gradually shifts across the human life span and reverses in old age, while coupling strength remains unchanged. This shift is associated with markers for astrocyte activation in old age. The shifting hierarchy resembles brain maturation, plateau, and wear processes. This study furthers our comprehension of this important neurophysiological process and its dynamic evolution across the human life span.
Topics: Female; Male; Humans; Aged; Adolescent; Young Adult; Adult; Middle Aged; Aged, 80 and over; Aging; Sleep; Longevity; Sleep, Slow-Wave; Amnesia
PubMed: 37586871
DOI: 10.1523/JNEUROSCI.0586-23.2023 -
CNS & Neurological Disorders Drug... 2024One-trial appetitive learning developed from one-trial passive avoidance learning as a standard test of retrograde amnesia. It consists of one learning trial followed by... (Review)
Review
One-trial appetitive learning developed from one-trial passive avoidance learning as a standard test of retrograde amnesia. It consists of one learning trial followed by a retention test, in which physiological manipulations are presented. As in passive avoidance learning, food- or waterdeprived rats or mice finding food or water inside an enclosure are vulnerable to the retrograde amnesia produced by electroconvulsive shock treatment or the injection of various drugs. In one-trial taste or odor learning conducted in rats, birds, snails, bees, and fruit flies, there is an association between a food item or odorant and contextual stimuli or the unconditioned stimulus of Pavlovian conditioning. The odor-related task in bees was sensitive to protein synthesis inhibition as well as cholinergic receptor blockade, both analogous to results found on the passive avoidance response in rodents, while the task in fruit flies was sensitive to genetic modifications and aging, as seen in the passive avoidance response of genetically modified and aged rodents. These results provide converging evidence of interspecies similarities underlying the neurochemical basis of learning.
Topics: Animals; Avoidance Learning; Learning; Humans; Appetitive Behavior
PubMed: 37287290
DOI: 10.2174/1871527322666230607152758 -
Anasthesiologie, Intensivmedizin,... Jul 2023Electroconvulsive therapy (ECT) is an established therapeutic method for the treatment of severe mental disorders refractory to pharmaco- and psychotherapy. ECT is a...
Electroconvulsive therapy (ECT) is an established therapeutic method for the treatment of severe mental disorders refractory to pharmaco- and psychotherapy. ECT is a first-line treatment option in delusional disorders, severe depression with acute suicidal tendency or life-threatening catatonia. Usually, ECT is performed as a treatment series. Under short-term anaesthesia and muscle relaxation, tonic-clonic seizures are induced using an external stimulation electrode. Convulsion can be exerted by uni- or bipolar stimulation using an electric charge up to 1000 millicoulomb (mC) with an amperage of 900 mA. Muscular relaxation is necessary to prevent injuries caused by uncontrolled movements during convulsion. During paralysis, consciousness is blocked by general anaesthesia, although ECT is associated with antegrade amnesia for seizure induction and the seizure itself. In the context of ECT, the ideal hypnotic should be characterised by rapid onset, short duration of action and negligible anticonvulsive effects (i.e., least possible impact on seizure quality and duration). As mutual awareness of psychiatric and anaesthesiologic techniques is essential for safe and effective conduction of ECT, this article presents ECT both from the psychiatrist's and the anaesthesiologist's perspective.
Topics: Humans; Electroconvulsive Therapy; Anesthesia, General; Seizures
PubMed: 37582353
DOI: 10.1055/a-1925-6993 -
Nature Communications Oct 2023Ketamine commonly and rapidly induces dissociative and other altered states of consciousness (ASCs) in humans. However, the neural mechanisms that contribute to these... (Randomized Controlled Trial)
Randomized Controlled Trial
Ketamine commonly and rapidly induces dissociative and other altered states of consciousness (ASCs) in humans. However, the neural mechanisms that contribute to these experiences remain unknown. We used functional neuroimaging to engage key regions of the brain's affective circuits during acute ketamine-induced ASCs within a randomized, multi-modal, placebo-controlled design examining placebo, 0.05 mg/kg ketamine, and 0.5 mg/kg ketamine in nonclinical adult participants (NCT03475277). Licensed clinicians monitored infusions for safety. Linear mixed effects models, analysis of variance, t-tests, and mediation models were used for statistical analyses. Our design enabled us to test our pre-specified primary and secondary endpoints, which were met: effects of ketamine across dose conditions on (1) emotional task-evoked brain activity, and (2) sub-components of dissociation and other ASCs. With this design, we also could disentangle which ketamine-induced affective brain states are dependent upon specific aspects of ASCs. Differently valenced ketamine-induced ASCs mediated opposing effects on right anterior insula activity. Participants experiencing relatively higher depersonalization induced by 0.5 mg/kg of ketamine showed relief from negative brain states (reduced task-evoked right anterior insula activity, 0.39 SD). In contrast, participants experiencing dissociative amnesia showed an exacerbation of insula activity (0.32 SD). These results in nonclinical participants may shed light on the mechanisms by which specific dissociative states predict response to ketamine in depressed individuals.
Topics: Adult; Humans; Brain; Consciousness; Emotions; Ketamine
PubMed: 37857620
DOI: 10.1038/s41467-023-42141-5