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1.
Epilepsia ; 65(6): 1589-1604, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38687128

ABSTRACT

OBJECTIVE: Although disparities have been described in epilepsy care, their contribution to status epilepticus (SE) and associated outcomes remains understudied. METHODS: We used the 2010-2019 National Inpatient Sample to identify SE hospitalizations using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)/ICD-10-CM codes. SE prevalence was stratified by demographics. Logistic regression was used to assess factors associated with electroencephalographic (EEG) monitoring, intubation, tracheostomy, gastrostomy, and mortality. RESULTS: There were 486 861 SE hospitalizations (2010-2019), primarily at urban teaching hospitals (71.3%). SE prevalence per 10 000 admissions was 27.3 for non-Hispanic (NH)-Blacks, 16.1 for NH-Others, 15.8 for Hispanics, and 13.7 for NH-Whites (p < .01). SE prevalence was higher in the lowest (18.7) compared to highest income quartile (18.7 vs. 14, p < .01). Older age was associated with intubation, tracheostomy, gastrostomy, and in-hospital mortality. Those ≥80 years old had the highest odds of intubation (odds ratio [OR] = 1.5, 95% confidence interval [CI] = 1.43-1.58), tracheostomy (OR = 2, 95% CI = 1.75-2.27), gastrostomy (OR = 3.37, 95% CI = 2.97-3.83), and in-hospital mortality (OR = 6.51, 95% CI = 5.95-7.13). Minority populations (NH-Black, NH-Other, and Hispanic) had higher odds of tracheostomy and gastrostomy compared to NH-White populations. NH-Black people had the highest odds of tracheostomy (OR = 1.7, 95% CI = 1.57-1.86) and gastrostomy (OR = 1.78, 95% CI = 1.65-1.92). The odds of receiving EEG monitoring rose progressively with higher income quartile (OR = 1.47, 95% CI = 1.34-1.62 for the highest income quartile) and was higher for those in urban teaching compared to rural hospitals (OR = 12.72, 95% CI = 8.92-18.14). Odds of mortality were lower (compared to NH-Whites) in NH-Blacks (OR = .71, 95% CI = .67-.75), Hispanics (OR = .82, 95% CI = .76-.89), and those in the highest income quartiles (OR = .9, 95% CI = .84-.97). SIGNIFICANCE: Disparities exist in SE prevalence, tracheostomy, and gastrostomy utilization across age, race/ethnicity, and income. Older age and lower income are also associated with mortality. Access to EEG monitoring is modulated by income and urban teaching hospital status. Older adults, racial/ethnic minorities, and populations of lower income or rural location may represent vulnerable populations meriting increased attention to improve health outcomes and reduce disparities.


Subject(s)
Healthcare Disparities , Hospital Mortality , Status Epilepticus , Humans , Male , Female , Aged , Status Epilepticus/mortality , Status Epilepticus/therapy , Status Epilepticus/epidemiology , Middle Aged , Healthcare Disparities/statistics & numerical data , Aged, 80 and over , Adult , United States/epidemiology , Young Adult , Prevalence , Hospitalization/statistics & numerical data , Adolescent , Morbidity/trends , Electroencephalography , Tracheostomy/statistics & numerical data
3.
Epilepsia ; 65(3): 533-541, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38279786

ABSTRACT

A variety of terms, such as "antiepileptic," "anticonvulsant," and "antiseizure" have been historically applied to medications for the treatment of seizure disorders. Terminology is important because using terms that do not accurately reflect the action of specific treatments may result in a misunderstanding of their effects and inappropriate use. The present International League Against Epilepsy (ILAE) position paper used a Delphi approach to develop recommendations on English-language terminology applicable to pharmacological agents currently approved for treating seizure disorders. There was consensus that these medications should be collectively named "antiseizure medications". This term accurately reflects their primarily symptomatic effect against seizures and reduces the possibility of health care practitioners, patients, or caregivers having undue expectations or an incorrect understanding of the real action of these medications. The term "antiseizure" to describe these agents does not exclude the possibility of beneficial effects on the course of the disease and comorbidities that result from the downstream effects of seizures, whenever these beneficial effects can be explained solely by the suppression of seizure activity. It is acknowledged that other treatments, mostly under development, can exert direct favorable actions on the underlying disease or its progression, by having "antiepileptogenic" or "disease-modifying" effects. A more-refined terminology to describe precisely these actions needs to be developed.


Subject(s)
Epilepsy , Humans , Epilepsy/drug therapy , Epilepsy/etiology , Anticonvulsants/therapeutic use , Behavior Therapy , Consensus , Caregivers
4.
J Pain ; 25(3): 642-658, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37777034

ABSTRACT

Women develop chronic pain during their reproductive years more often than men, and estrogen and progesterone regulate this susceptibility. We tested whether brain progesterone receptor (PR) signaling regulates pain susceptibility. During the estrous cycle, animals were more sensitive to mechanical stimulus during the estrus stage than in the diestrus stage, suggesting a role for reproductive hormones, estrogen, and progesterone. Progesterone treatment of ovariectomized and estrogen-primed mice caused a delayed reduction in the mechanical threshold. Segesterone, a specific agonist of PRs replicated this effect, whereas, the segesterone-induced reduction in mechanical threshold was blocked in the mice lacking PRs in the nervous system. Segesterone treatment also did not alter mechanical threshold in adult male and juvenile female mice. PR activation increased the cold sensitivity but did not affect the heat and light sensitivity. We evaluated whether PR activation altered experimental migraine. Segesterone and nitroglycerin when administered sequentially, reduced the pain threshold but not when given separately. PRs were expressed in several components of the migraine ascending pain pathway, and their deletion blocked the painful effects of nitroglycerin. PR activation also increased the number of active neurons in the components of the migraine ascending pain pathway. These studies have uncovered a pain-regulating function of PRs. Targeting PRs may provide a novel therapeutic avenue to treat chronic pain and migraine in women. PERSPECTIVE: This article provides evidence for the role of progesterone receptors in regulating pain sensitivity and migraine susceptibility in females. Progesterone receptors may be a therapeutic target to treat chronic pain conditions more prevalent in women than men.


Subject(s)
Chronic Pain , Migraine Disorders , Humans , Female , Male , Mice , Animals , Receptors, Progesterone/metabolism , Progesterone/pharmacology , Chronic Pain/drug therapy , Nitroglycerin , Migraine Disorders/drug therapy , Estrogens
5.
Anesthesiology ; 140(4): 729-741, 2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38157434

ABSTRACT

BACKGROUND: Previous research suggests that sevoflurane anesthesia may prevent the brain from accessing rapid eye movement (REM) sleep. If true, then patterns of neural activity observed in REM-on and REM-off neuronal populations during recovery from sevoflurane should resemble those seen after REM sleep deprivation. In this study, the authors hypothesized that, relative to controls, animals exposed to sevoflurane present with a distinct expression pattern of c-Fos, a marker of neuronal activation, in a cluster of nuclei classically associated with REM sleep, and that such expression in sevoflurane-exposed and REM sleep-deprived animals is largely similar. METHODS: Adult rats and Targeted Recombination in Active Populations mice were implanted with electroencephalographic electrodes for sleep-wake recording and randomized to sevoflurane, REM deprivation, or control conditions. Conventional c-Fos immunohistochemistry and genetically tagged c-Fos labeling were used to quantify activated neurons in a group of REM-associated nuclei in the midbrain and basal forebrain. RESULTS: REM sleep duration increased during recovery from sevoflurane anesthesia relative to controls (157.0 ± 24.8 min vs. 124.2 ± 27.8 min; P = 0.003) and temporally correlated with increased c-Fos expression in the sublaterodorsal nucleus, a region active during REM sleep (176.0 ± 36.6 cells vs. 58.8 ± 8.7; P = 0.014), and decreased c-Fos expression in the ventrolateral periaqueductal gray, a region that is inactive during REM sleep (34.8 ± 5.3 cells vs. 136.2 ± 19.6; P = 0.001). Fos changes similar to those seen in sevoflurane-exposed mice were observed in REM-deprived animals relative to controls (sublaterodorsal nucleus: 85.0 ± 15.5 cells vs. 23.0 ± 1.2, P = 0.004; ventrolateral periaqueductal gray: 652.8 ± 71.7 cells vs. 889.3 ± 66.8, P = 0.042). CONCLUSIONS: In rodents recovering from sevoflurane, REM-on and REM-off neuronal activity maps closely resemble those of REM sleep-deprived animals. These findings provide new evidence in support of the idea that sevoflurane does not substitute for endogenous REM sleep.


Subject(s)
Rodentia , Sleep, REM , Animals , Mice , Rats , Electroencephalography , Proto-Oncogene Proteins c-fos , Rodentia/metabolism , Sevoflurane , Sleep/physiology , Sleep Deprivation/metabolism , Sleep, REM/physiology
6.
Prog Neurobiol ; 231: 102531, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37778436

ABSTRACT

Repeated generalized tonic-clonic seizures (GTCSs) are the most critical risk factor for sudden unexpected death in epilepsy (SUDEP). GTCSs can cause fatal apnea. We investigated neuronal plasticity mechanisms that precipitate postictal apnea and seizure-induced death. Repeated seizures worsened behavior, precipitated apnea, and enlarged active neuronal circuits, recruiting more neurons in such brainstem nuclei as periaqueductal gray (PAG) and dorsal raphe, indicative of brainstem plasticity. Seizure-activated neurons are more excitable and have enhanced AMPA-mediated excitatory transmission after a seizure. Global deletion of the GluA1 subunit of AMPA receptors abolishes postictal apnea and seizure-induced death. Treatment with a drug that blocks Ca2+-permeable AMPA receptors also renders mice apnea-free with five-fold better survival than untreated mice. Repeated seizures traffic the GluA1 subunit-containing AMPA receptors to synapses, and blocking this mechanism decreases the probability of postictal apnea and seizure-induced death.


Subject(s)
Apnea , Receptors, AMPA , Mice , Animals , Receptors, AMPA/therapeutic use , Seizures/drug therapy , Brain Stem , Risk Factors
7.
bioRxiv ; 2023 Aug 07.
Article in English | MEDLINE | ID: mdl-37609239

ABSTRACT

Women develop chronic pain during their reproductive years more often than men, and estrogen and progesterone regulate this susceptibility. We tested whether brain progesterone receptor (PR) signaling regulates pain susceptibility. During the estrous cycle, animals were more sensitive to pain during the estrus stage than in the diestrus stage, suggesting a role for reproductive hormones, estrogen, and progesterone. We measured the pain threshold daily for four days in ovariectomized, estrogen-primed animals treated with progesterone. The pain threshold was lower 2 days later and stayed that way for the duration of the testing. A specific progesterone-receptor (PR) agonist, segesterone, promoted pain, and mice lacking PR in the brain (PRKO) did not experience lowered pain threshold when treated with progesterone or segesterone. PR activation increased the cold sensitivity but did not affect the heat sensitivity and had a small effect on light sensitivity. Finally, we evaluated whether PR activation altered experimental migraine. Segesterone and nitroglycerin (NTG) when administered sequentially, reduced pain threshold but not separately. These studies have uncovered a pain-regulating function of PRs. Targeting PRs may provide a novel therapeutic avenue to treat chronic pain in women.

8.
Neurology ; 101(16): e1633-e1639, 2023 10 17.
Article in English | MEDLINE | ID: mdl-37580166

ABSTRACT

Most clinical trials of treatment efficacy evaluate benefits and harms separately. Investigators generally rate the primary outcome of a trial with a binary outcome measure and consider harms separately as adverse events. This approach fails to recognize finer gradations of patient response, correlations between benefits and harms, and the overall effects on individual patients. For example, in status epilepticus trials, efficacy is often defined as the absence of clinically apparent seizures with recovery of consciousness. Such an efficacy outcome fails to recognize that some causes of status epilepticus, such as subarachnoid hemorrhage or stroke, may not be accompanied by return of consciousness, and the need to intubate a patient may be classified as treatment failure even if status was successfully terminated. The Desirability of Outcome Ranking (DOOR) method uses a different approach. The DOOR method involves comparing the experiences of trial participants in different treatment arms by the desirability of the overall patient outcome. Using status epilepticus treatment as an example, a patient who experiences successful termination of status epilepticus but with major side effects would have a less desirable outcome than a patient with treatment success and minor side effects, who in turn would have a less desirable outcome than a patient with treatment success but no side effects. This is a patient-centered approach because it considers treatment efficacy in the context of the costs borne by the patient, for example, toxicity in achieving efficacy. Thus, DOOR considers both the benefits and harms to individual patients in assessing the outcome of a clinical trial. In this article, we present the rationale for the use of DOOR, the issues involved in the development of and statistical analyses of an ordinal outcome, and an example of the potential application of the DOOR method to a clinical trial of convulsive status epilepticus.


Subject(s)
Status Epilepticus , Humans , Status Epilepticus/drug therapy , Status Epilepticus/chemically induced , Seizures/drug therapy , Risk Assessment , Treatment Outcome , Outcome Assessment, Health Care , Anticonvulsants/therapeutic use
9.
Ann Clin Transl Neurol ; 10(10): 1873-1884, 2023 10.
Article in English | MEDLINE | ID: mdl-37632130

ABSTRACT

OBJECTIVE: Status epilepticus (SE) requires rapid intervention to prevent cerebral injury and mortality. The ketogenic diet, which bypasses glycolysis, is a promising remedy for patients with refractory SE. We tested the role of glycolytic lactate production in sustaining SE. METHODS: Extracellular lactate and glucose concentration during a seizure and SE in vivo was measured using lactate and glucose biosensors. A lactate dehydrogenase inhibitor, oxamate, blocked pyruvate to lactate conversion during SE. Video-EEG recordings evaluated seizure duration, severity, and immunohistochemistry was used to determine neuronal loss. Genetically encoded calcium indicator GCaMP7 was used to study the effect of oxamate on CA1 pyramidal neurons in vitro. Spontaneous excitatory postsynaptic currents (sEPSCs) were recorded from CA1 neurons to study oxamate's impact on neurotransmission. RESULTS: The extracellular glucose concentration dropped rapidly during seizures, and lactate accumulated in the extracellular space. Inhibition of pyruvate to lactate conversion with oxamate terminated SE in mice. There was less neuronal loss in treated compared to control mice. Oxamate perfusion decreased tonic and phasic neuronal activity of GCaMP7-expressing CA1 pyramidal neurons in vitro. Oxamate application reduced the frequency, but not amplitude of sEPSCs recorded from CA1 neurons, suggesting an effect on the presynaptic glutamatergic neurotransmission. INTERPRETATION: A single seizure and SE stimulate lactate production. Diminishing pyruvate to lactate conversion with oxamate terminated SE and reduced associated neuronal death. Oxamate reduced neuronal excitability and excitatory neurotransmission at the presynaptic terminal. Glycolytic lactate production sustains SE and is an attractive therapeutic target.


Subject(s)
Lactic Acid , Status Epilepticus , Humans , Mice , Animals , Glucose , Seizures , Glycolysis , Pyruvates
10.
Int J Mol Sci ; 24(14)2023 Jul 12.
Article in English | MEDLINE | ID: mdl-37511107

ABSTRACT

Over a third of patients with temporal lobe epilepsy (TLE) are not effectively treated with current anti-seizure drugs, spurring the development of gene therapies. The injection of adeno-associated viral vectors (AAV) into the brain has been shown to be a safe and viable approach. However, to date, AAV expression of therapeutic genes has not been regulated. Moreover, a common property of antiepileptic drugs is a narrow therapeutic window between seizure control and side effects. Therefore, a long-term goal is to develop drug-inducible gene therapies that can be regulated by clinically relevant drugs. In this study, a first-generation doxycycline-regulated gene therapy that delivered an engineered version of the leak potassium channel Kcnk2 (TREK-M) was injected into the hippocampus of male rats. Rats were electrically stimulated until kindled. EEG was monitored 24/7. Electrical kindling revealed an important side effect, as even low expression of TREK M in the absence of doxycycline was sufficient to cause rats to develop spontaneous recurring seizures. Treating the epileptic rats with doxycycline successfully reduced spontaneous seizures. Localization studies of infected neurons suggest seizures were caused by expression in GABAergic inhibitory neurons. In contrast, doxycycline increased the expression of TREK-M in excitatory neurons, thereby reducing seizures through net inhibition of firing. These studies demonstrate that drug-inducible gene therapies are effective in reducing spontaneous seizures and highlight the importance of testing for side effects with pro-epileptic stressors such as electrical kindling. These studies also show the importance of evaluating the location and spread of AAV-based gene therapies in preclinical studies.


Subject(s)
Drug-Related Side Effects and Adverse Reactions , Epilepsy, Temporal Lobe , Epilepsy , Rats , Male , Animals , Doxycycline/pharmacology , Neurons/metabolism , Epilepsy/metabolism , Epilepsy, Temporal Lobe/metabolism , Hippocampus/metabolism , Genetic Therapy , Drug-Related Side Effects and Adverse Reactions/metabolism , Disease Models, Animal
11.
Epilepsy Curr ; 23(3): 169-174, 2023.
Article in English | MEDLINE | ID: mdl-37334420

ABSTRACT

Mapping neuronal circuits that generate focal to bilateral tonic-clonic seizures is essential for understanding general principles of seizure propagation and modifying the risk of death and injury due to bilateral motor seizures. We used novel techniques developed over the past decade to study these circuits. We propose the general hypothesis that at the mesoscale, seizures follow anatomical projections of the seizure focus, preferentially activating more excitable neurons.

12.
Epilepsy Behav ; 141: 109148, 2023 04.
Article in English | MEDLINE | ID: mdl-36907083

ABSTRACT

Alterations to cardiac electrical conduction are some of the most frequently observed systemic complications of seizures, with autonomic dysregulation cited as the principal driver for these alterations. In this prospective study, we use 6-lead continuous ECG monitoring in hospitalized patients with epilepsy to trend heart rate patterns in the postictal period. A total of 117 seizures in 45 patients met the criteria for analysis. There was a postictal heart rate increase of 61% (n = 72 seizures), and a decline in heart rate (deceleration) following 38.5% (n = 45). Using 6-lead ECGs for waveform analysis revealed that there was PR prolongation accompanying those seizures that were associated with postictal bradycardia.


Subject(s)
Bradycardia , Epilepsy , Humans , Bradycardia/complications , Prospective Studies , Electroencephalography/adverse effects , Epilepsy/complications , Seizures/complications , Heart Rate/physiology , Electrocardiography
13.
Sci Rep ; 13(1): 2164, 2023 02 07.
Article in English | MEDLINE | ID: mdl-36750584

ABSTRACT

Progesterone and its receptors (PRs) participate in mating and reproduction, but their role in spatial declarative memory is not understood. Male mice expressed PRs, predominately in excitatory neurons, in brain regions that support spatial memory, such as the hippocampus and entorhinal cortex (EC). Furthermore, segesterone, a specific PR agonist, activates neurons in both the EC and hippocampus. We assessed the contribution of PRs in promoting spatial and non-spatial cognitive learning in male mice by examining the performance of mice lacking this receptor (PRKO), in novel object recognition, object placement, Y-maze alternation, and Morris-Water Maze (MWM) tasks. In the recognition test, the PRKO mice preferred the familiar object over the novel object. A similar preference for the familiar object was also seen following the EC-specific deletion of PRs. PRKO mice were also unable to recognize the change in object position. We confirmed deficits in spatial memory of PRKO mice by testing them on the Y-maze forced alternation and MWM tasks; PR deletion affected animal's performance in both these tasks. In contrast to spatial tasks, PR removal did not alter the response to fear conditioning. These studies provide novel insights into the role of PRs in facilitating spatial, declarative memory in males, which may help with finding reproductive partners.


Subject(s)
Limbic System , Maze Learning , Receptors, Progesterone , Spatial Memory , Animals , Male , Mice , Entorhinal Cortex/physiology , Hippocampus/physiology , Limbic System/physiology , Maze Learning/physiology , Memory Disorders/physiopathology , Progesterone/physiology , Receptors, Progesterone/physiology , Spatial Memory/physiology
14.
Epilepsy Behav ; 141: 109066, 2023 04.
Article in English | MEDLINE | ID: mdl-36609129

ABSTRACT

We present the rationale for testing ketamine as an add-on therapy for treating benzodiazepine refractory (established) status epilepticus. In animal studies, ketamine terminates benzodiazepine refractory status epilepticus by interfering with the pathophysiological mechanisms and is a neuroprotectant. Ketamine does not suppress respiration when used for sedation and anesthesia. A Series of reports suggest that ketamine can help terminate refractory and super refractory status epilepticus. We propose to use 1 or 3 mg/Kg ketamine intravenously based on animal-to-human conversion and pharmacokinetic studies. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.


Subject(s)
Ketamine , Neuroprotective Agents , Status Epilepticus , Ketamine/administration & dosage , Ketamine/therapeutic use , Anticonvulsants , Benzodiazepines/pharmacology , Neuroprotective Agents/administration & dosage , Neuroprotective Agents/therapeutic use , Seizures/drug therapy , Status Epilepticus/drug therapy , Humans
15.
Alzheimers Dement ; 19(6): 2697-2706, 2023 06.
Article in English | MEDLINE | ID: mdl-36648207

ABSTRACT

Alzheimer's disease (AD) patients have a high risk of developing mesial temporal lobe epilepsy (MTLE) and subclinical epileptiform activity. MTLE in AD worsens outcomes. Therefore, we need to understand the overlap between these disease processes. We hypothesize that AD with MTLE represents a distinct subtype of AD, with the interplay between tau and epileptiform activity at its core. We discuss shared pathological features including histopathology, an initial mesial temporal lobe (MTL) hyperexcitability followed by MTL dysfunction and involvement of same networks in memory (AD) and seizures (MTLE). We provide evidence that tau accumulation linearly increases neuronal hyperexcitability, neuronal hyper-excitability increases tau secretion, tau can provoke seizures, and tau reduction protects against seizures. We speculate that AD genetic mutations increase tau, which causes proportionate neuronal loss and/or hyperexcitability, leading to seizures. We discuss that tau burden in MTLE predicts cognitive deficits among (1) AD and (2) MTLE without AD. Finally, we explore the possibility that anti-seizure medications improve cognition by reducing neuronal hyper-excitability, which reduces seizures and tau accumulation and spread. HIGHLIGHTS: We hypothesize that patients with Alzheimer's disease (AD) and mesial temporal lobe epilepsy (MTLE) represents a distinct subtype of AD. AD and MTLE share histopathological features and involve overlapping neuronal and cortical networks. Hyper-phosphorylated tau (pTau) increases neuronal excitability and provoke seizures, neuronal excitability increases pTau, and pTau reduction reduces neuronal excitability and protects against seizures. The pTau burden in MTL predicts cognitive deficits among (1) AD and (2) MTLE without AD. We speculate that anti-seizure medications improve cognition by reducing neuronal excitability, which reduces seizures and pTau.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Epilepsy, Temporal Lobe , Humans , Epilepsy, Temporal Lobe/drug therapy , Epilepsy, Temporal Lobe/pathology , Epilepsy, Temporal Lobe/psychology , Hippocampus/pathology , Alzheimer Disease/pathology , Temporal Lobe/pathology , Cognitive Dysfunction/pathology
16.
Brain Commun ; 5(1): fcac298, 2023.
Article in English | MEDLINE | ID: mdl-36655171

ABSTRACT

Recent studies suggest that changes in neuronal metabolism are associated with epilepsy. High rates of ATP depletion, lactate dehydrogenase A and lactate production have all been found in epilepsy patients, animal and tissue culture models. As such, it can be hypothesized that chronic seizures lead to continuing elevations in neuronal energy demand which may lead to an adapted metabolic response and elevations of lactate dehydrogenase A. In this study, we examine elevations in the lactate dehydrogenase A protein as a long-term cellular adaptation to elevated metabolic demand from chronic neuronal activation. We investigate this cellular adaptation in human tissue samples and explore the mechanisms of lactate dehydrogenase A upregulation using cultured neurones treated with low Mg2+, a manipulation that leads to NMDA-mediated neuronal activation. We demonstrate that human epileptic tissue preferentially upregulates neuronal lactate dehydrogenase A, and that in neuronal cultures chronic and repeated elevations in neural activity lead to upregulation of neuronal lactate dehydrogenase A. Similar to states of hypoxia, this metabolic change occurs through the AMP-activated protein kinase/hypoxia-inducible factor-1α pathway. Our data therefore reveal a novel long-term bioenergetic adaptation that occurs in chronically activated neurones and provide a basis for understanding the interplay between metabolism and neural activity during epilepsy.

17.
IEEE Trans Neural Netw Learn Syst ; 34(10): 7608-7620, 2023 Oct.
Article in English | MEDLINE | ID: mdl-35120011

ABSTRACT

Transform-domain least mean squares (TDLMS) adaptive filters encompass the class of learning algorithms where the input data are subjected to a data-independent unitary transform followed by a power normalization stage as preprocessing steps. Because conventional transformations are not data-dependent, this preconditioning procedure was shown theoretically to improve the convergence of the least mean squares (LMS) filter only for certain classes of input data. So, one can tailor the transformation to the class of data. However, in reality, if the class of input data is not known beforehand, it is difficult to decide which transformation to use. Thus, there is a need to devise a learning framework to obtain such a preconditioning transformation using input data prior to applying on the input data. It is hypothesized that the underlying topology of the data affects the selection of the transformation. With the input modeled as a weighted finite graph, our method, called preconditioning using graph (PrecoG), adaptively learns the desired transform by recursive estimation of the graph Laplacian matrix. We show the efficacy of the transform as a generalized split preconditioner on a linear system of equations and in Hebbian-LMS learning models. In terms of the improvement of the condition number after applying the transformation, PrecoG performs significantly better than the existing state-of-the-art techniques that involve unitary and nonunitary transforms.

18.
Brain ; 146(5): 1888-1902, 2023 05 02.
Article in English | MEDLINE | ID: mdl-36346130

ABSTRACT

Repetitively firing neurons during seizures accelerate glycolysis to meet energy demand, which leads to the accumulation of extracellular glycolytic by-product lactate. Here, we demonstrate that lactate rapidly modulates neuronal excitability in times of metabolic stress via the hydroxycarboxylic acid receptor type 1 (HCA1R) to modify seizure activity. The extracellular lactate concentration, measured by a biosensor, rose quickly during brief and prolonged seizures. In two epilepsy models, mice lacking HCA1R (lactate receptor) were more susceptible to developing seizures. Moreover, HCA1R deficient (knockout) mice developed longer and more severe seizures than wild-type littermates. Lactate perfusion decreased tonic and phasic activity of CA1 pyramidal neurons in genetically encoded calcium indicator 7 imaging experiments. HCA1R agonist 3-chloro-5-hydroxybenzoic acid (3CL-HBA) reduced the activity of CA1 neurons in HCA1R WT but not in knockout mice. In patch-clamp recordings, both lactate and 3CL-HBA hyperpolarized CA1 pyramidal neurons. HCA1R activation reduced the spontaneous excitatory postsynaptic current frequency and altered the paired-pulse ratio of evoked excitatory postsynaptic currents in HCA1R wild-type but not in knockout mice, suggesting it diminished presynaptic release of excitatory neurotransmitters. Overall, our studies demonstrate that excessive neuronal activity accelerates glycolysis to generate lactate, which translocates to the extracellular space to slow neuronal firing and inhibit excitatory transmission via HCA1R. These studies may identify novel anticonvulsant target and seizure termination mechanisms.


Subject(s)
Lactic Acid , Neurons , Mice , Animals , Neurons/physiology , Pyramidal Cells/physiology , Mice, Knockout , Seizures , Hippocampus
19.
Cereb Cortex ; 33(8): 4645-4653, 2023 04 04.
Article in English | MEDLINE | ID: mdl-36137566

ABSTRACT

Postnatal maturation of the motor cortex is vital to developing a variety of functions, including the capacity for motor learning. The first postnatal weeks involve many neuronal and synaptic changes, which differ by region and layer, likely due to different functions and needs during development. Motor cortex layer II/III is critical to receiving and integrating inputs from somatosensory cortex and generating attentional signals that are important in motor learning and planning. Here, we examined the neuronal and synaptic changes occurring in layer II/III pyramidal neurons of the mouse motor cortex from the neonatal (postnatal day 10) to young adult (postnatal day 30) period, using a combination of electrophysiology and biochemical measures of glutamatergic receptor subunits. There are several changes between p10 and p30 in these neurons, including increased dendritic branching, neuronal excitability, glutamatergic synapse number and synaptic transmission. These changes are critical to ongoing plasticity and capacity for motor learning during development. Understanding these changes will help inform future studies examining the impact of early-life injury and experiences on motor learning and development capacity.


Subject(s)
Motor Cortex , Mice , Animals , Motor Cortex/physiology , Pyramidal Cells/physiology , Neurons/physiology , Synaptic Transmission , Synapses/physiology
20.
Stat Biopharm Res ; 15(4): 820-825, 2023.
Article in English | MEDLINE | ID: mdl-38361772

ABSTRACT

Ordinal outcomes are common in medicine and can be analyzed in many ways, but the distribution of ordinal data can present unique challenges. The proposed KESETT study is a three-armed, randomized trial comparing two doses of ketamine plus levetiracetam to levetiracetam alone for treating patients with benzodiazepine-refractory status epilepticus. A Bayesian, adaptive clinical trial is proposed employing an ordinal primary outcome at 60 minutes ranging from 1 (improving consciousness and seizure cessation) to 5 (life-threatening event/death). Based on a previous study, the ordinal outcome is expected to have a bimodal distribution, with the effect of treatment expected to be non-proportional across the outcome scale. As such, approaches relying on assuming proportionality of the odds are not appropriate. We propose for this scenario an analytic approach to compare ordinal outcomes using the expected score derived from the posterior distribution for each treatment group. This approach requires minimal assumptions, maintains the benefit of using the full ordinal scale, is interpretable, and can be used in a Bayesian analysis framework. We compare this new approach under multiple simulated scenarios to 3 traditional frequentist approaches. The new approach controls type I error and power, resulting in a sizable reduction in sample size relative to a non-parametric test.

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