KATP channel mutation disrupts hippocampal network activity and nocturnal gamma shifts

Investigation of the relationship between Body Mass Index and epilepsy

OBJECTIVE

To examine the clinical characteristics and influencing factors among epilepsy patients with varying Body Mass Index (BMI), and to propose new approaches for the prevention and treatment of epilepsy.

METHODS

A total of 250 adult patients, newly diagnosed with epilepsy and not yet treated with antiepileptic drugs at the First Affiliated Hospital of Dali University between January 2017 and December 2022, were randomly selected as the experimental group. Additionally, 250 healthy individuals from the same period served as the control group to investigate the relationship between BMI and epilepsy. Univariate analysis and ordered multiple logistic regression were used to further identify factors influencing BMI in patients with epilepsy.

RESULTS

A significant difference in BMI was found between adults newly diagnosed with epilepsy who had not yet used antiepileptic drugs, and healthy individuals (P = 0.001). The obesity rate was higher in epilepsy patients (20.4 %) compared to healthy adults (9.6 %).The ordered multiple logistic regression analysis revealed that gender(P = 0.003), age(P = 0.029), nation(P = 0.008), occupation(P < 0.001), etiology(P = 0.001), NLR(P = 0.022), and SIRI(P = 0.008) were all significant factors influencing BMI in epilepsy patients.

CONCLUSION

People with epilepsy are more likely to also be obese and is associated with factors such as gender, age, nation, occupation, etiology, and inflammatory markers. In clinical practice, it is essential to monitor and manage BMI in epilepsy patients, identify preventable risk factors, and ultimately enhance treatment outcomes and quality of life.

ATP-sensitive potassium channels alter glycolytic flux to modulate cortical activity and sleep

Metabolism plays a key role in the maintenance of sleep/wake states. Brain lactate fluctuations are a biomarker of sleep/wake transitions, where increased interstitial fluid (ISF) lactate levels are associated with wakefulness and decreased ISF lactate is required for sleep. ATP-sensitive potassium (KATP) channels couple glucose-lactate metabolism with excitability. Using mice lacking KATP channel activity (e.g., Kir6.2-/- mice), we explored how changes in glucose utilization affect cortical electroencephalography (EEG) activity and sleep/wake homeostasis. In the brain, Kir6.2-/- mice shunt glucose toward glycolysis, reducing neurotransmitter biosynthesis and dampening cortical EEG activity. Kir6.2-/- mice spent more time awake at the onset of the light period due to altered ISF lactate dynamics. Together, we show that Kir6.2-KATP channels act as metabolic sensors to gate arousal by maintaining the metabolic stability of sleep/wake states and providing the metabolic flexibility to transition between states.

Sulfonylurea Receptor Pharmacology Alters the Performance of Two Central Pattern Generating Circuits in Cancer borealis

Neuronal activity and energy supply must maintain a fine balance for neuronal fitness. Various channels of communication between the two could impact network output in different ways. Sulfonylurea receptors (SURs) are a modification of ATP-binding cassette proteins that confer ATP-dependent gating on their associated ion channels. They are widely expressed and link metabolic states directly to neuronal activity. The role they play varies in different circuits, both enabling bursting and inhibiting activity in pathological conditions. The crab, Cancer borealis, has central pattern generators (CPGs) that fire in rhythmic bursts nearly constantly and it is unknown how energy availability influences these networks. The pyloric network of the stomatogastric ganglion and the cardiac ganglion (CG) control rhythmic contractions of the foregut and heart, respectively. Known SUR agonists and antagonists produce opposite effects in the two CPGs. Pyloric rhythm activity completely stops in the presence of a SUR agonist, and activity increases in SUR blockers. This results from a decrease in the excitability of pyloric dilator neurons, which are a part of the pacemaker kernel. The neurons of the CG, paradoxically, increase firing within bursts in SUR agonists, and bursting slows in SUR antagonists. Analyses of the agonist-affected conductance properties present biophysical effects that do not trivially match those of mammalian SUR-dependent conductances. We suggest that SUR-associated conductances allow different neurons to respond to energy states in different ways through a common mechanism.

Sulfonylurea receptor coupled conductances alter the performace of two central pattern generating circuits in Cancer borealis

Neuronal activity and energy supply must maintain a fine balance for neuronal fitness. Various channels of communication between the two could impact network output in different ways. Sulfonylurea receptors (SURs) are a modification of ATP-binding cassette proteins (ABCs) that confer ATP-dependent gating on their associated ion channels. They are widely expressed and link metabolic states directly to neuronal activity. The role they play varies in different circuits, both enabling bursting and inhibiting activity in pathological conditions. The crab, Cancer borealis, has central patterns generators (CPGs) that fire in rhythmic bursts nearly constantly and it is unknown how energy availability influences these networks. The pyloric network of the stomatogastric ganglion (STG) and cardiac ganglion (GC) control rhythmic contractions of the foregut and heart respectively. Pharmacological manipulation of SURs results in opposite effects in the two CPGs. Neuronal firing completely stops in the STG when SUR-associated channels are open, and firing increases when the channels are closed. This results from a decrease in the excitability of pyloric dilator (PD) neurons, which are a part of the pacemaker kernel. The neurons of the CG, paradoxically, increase firing within bursts when SUR-associated channels are opened, and bursting slows when SUR-associated channels are closed. The channel permeability and sensitivities analyses present novel SUR-conductance biophysics, which nevertheless change activity in ways reminiscent of the predominantly studied mammalian receptor/channels. We suggest that SUR-associated conductances allow different neurons to respond to energy states in different ways through a common mechanism.

A Reduction in the Readily Releasable Vesicle Pool Impairs GABAergic Inhibition in the Hippocampus after Blood-Brain Barrier Dysfunction

Major burdens for patients suffering from stroke are cognitive co-morbidities and epileptogenesis. Neural network disinhibition and deficient inhibitive pulses for fast network activities may result from impaired presynaptic release of the inhibitory neurotransmitter GABA. To test this hypothesis, a cortical photothrombotic stroke was induced in Sprague Dawley rats, and inhibitory currents were recorded seven days later in the peri-infarct blood-brain barrier disrupted (BBBd) hippocampus via patch-clamp electrophysiology in CA1 pyramidal cells (PC). Miniature inhibitory postsynaptic current (mIPSC) frequency was reduced to about half, and mIPSCs decayed faster in the BBBd hippocampus. Furthermore, the paired-pulse ratio of evoked GABA release was increased at 100 Hz, and train stimulations with 100 Hz revealed that the readily releasable pool (RRP), usually assumed to correspond to the number of tightly docked presynaptic vesicles, is reduced by about half in the BBBd hippocampus. These pathophysiologic changes are likely to contribute significantly to disturbed fast oscillatory activity, like cognition-associated gamma oscillations or sharp wave ripples and epileptogenesis in the BBBd hippocampus.