Spectral and coupling characteristics of somatosensory cortex and centromedian thalamus differentiate between pre- and inter-ictal 5-9 Hz oscillations in a genetic rat model of absence epilepsy.

Spike-wave-discharges (SWD) are the electrophysiological hallmark of absence epilepsy. SWD are generated in the thalamo-cortical network and a seizure onset zone was identified in the somatosensory cortex (S1). We have shown before that inhibition of the centromedian thalamic nucleus (CM) in GAERS rats resulted in a selective suppression of the spike component while rhythmic cortical 5-9 Hz oscillations remained present.

Seizure Prediction in Genetic Rat Models of Absence Epilepsy: Improved Performance through Multiple-Site Cortico-Thalamic Recordings Combined with Machine Learning.

Seizure prediction is the grand challenge of epileptology. However, effort was devoted to prediction of focal seizures, while generalized seizures were regarded as stochastic events. Long-lasting local field potential (LFP) recordings containing several hundred generalized spike and wave discharges (SWDs), acquired at eight locations in the cortico-thalamic system of absence epileptic rats, were iteratively analyzed in all possible combinations of either two or three recording sites, by a wavelet-based algorithm, calculating the product of the wavelet-energy signaling increases in synchronicity.

Single-cell profiling of CNS border compartment leukocytes reveals that B cells and their progenitors reside in non-diseased meninges.

The CNS is ensheathed by the meninges and cerebrospinal fluid, and recent findings suggest that these CNS-associated border tissues have complex immunological functions. Unlike myeloid lineage cells, lymphocytes in border compartments have yet to be thoroughly characterized. Based on single-cell transcriptomics, we here identified a highly location-specific composition and expression profile of tissue-resident leukocytes in CNS parenchyma, pia-enriched subdural meninges, dura mater, choroid plexus and cerebrospinal fluid.

Stimulation of 5-HT receptors in anterodorsal BNST guides fear to predictable and unpredictable threat.

Through pharmacological manipulation of the serotonergic (5-Hydroxytryptamin, 5-HT) system, combined with behavioral analysis, we tested the hypothesis that fear responses to predictable and unpredictable threat are regulated through stimulation of 5-HT receptors (5-HT-R) in the anterodorsal section of the bed nucleus of the stria terminalis (adBNST). Local adBNST application of 5-HT1A-R antagonist WAY100635 and 5-HT1B-R antagonist NAS-181 before fear retrieval enhanced freezing, 24 h after predictable fear conditioning. In contrast, increased fear responses to unpredictable threat were blocked by 5-HT1A-R agonist Buspirone (given before conditioning or retrieval) and 5-HT1B-R agonist CP-94253 (applied before training).

Spike-wave discharges in absence epilepsy: segregation of electrographic components reveals distinct pathways of seizure activity.

Key Points: The major electrophysiological hallmarks of absence seizures are spike and wave discharges (SWDs), consisting of a sharp spike component and a slow wave component. In a widely accepted scheme, these components are functionally coupled and reflect an iterative progression of neuronal excitation during the spike and post-excitatory silence during the wave. In a genetic rat model of absence epilepsy, local pharmacological inhibition of the centromedian thalamus (CM) selectively suppressed the spike component, leaving self-contained waves in epidural recordings.