Biology subjects

Kinard, E. A.

Publications and source records attributed to Kinard, E. A..

2 recordsLinked to original sources

bioRxiv2025

Changes in slow oscillations and sleep spindles by auditory stimulation positively correlate with memory consolidation in children with epilepsy and controls

BackgroundSleep-dependent memory consolidation is supported by sleep spindles during stages 2 and 3 non-rapid eye movement sleep. Sleep spindles and sleep-dependent memory consolidation are both decreased in Rolandic epilepsy (RE). Non-invasive auditory stimulation evokes SOs and SO-spindle complexes in healthy adults but the impact on memory consolidation has been inconsistent. ObjectiveWe investigated the effects of auditory stimulation during sleep on SOs, SO-spindle complexes, and sleep-dependent memory consolidation in children with RE and controls. MethodsA prospective cross-over study was conducted in children with RE and control. Children completed two nap visits with auditory or sham stimulation. SOs and SO-spindle complexes rates were measured offline using validated detectors. Sleep-dependent memory consolidation was assessed using the motor sequence typing task. ResultsAuditory stimulation evoked SOs and SO-spindle complexes broadly with maximal effect over frontal electrodes. Compared to sham, stimulation delivered during background activity evoked SOs (29.8% increase, p<0.001) and SO-spindle complexes (16.8% increase, p<0.001) and stimulations delivered near the peak of an ongoing SO upstate maximally evoked SOs (51.3% increase, p<0.001) and SO-spindle complexes (32.3% increase, p<0.001). Changes in frontal SO (1.9% improvement per increase in SO/min; p<0.001) and SO-spindle complexes (9.5% improvement per increase in SO-spindle/min) event rates due to auditory stimulation positively predicted changes in sleep-dependent memory consolidation. ConclusionAuditory stimulation reliably modulates sleep oscillations when delivered on background activity and during the upstate of SOs. As increased event rates improve memory consolidation, stimulation paradigms to increase SO and SO-spindle complex rates are required to enhance memory.

neuroscience↗

bioRxiv2024

Impaired sleep-dependent memory consolidation predicted by reduced sleep spindles in Rolandic epilepsy

Background and ObjectivesSleep spindles are prominent thalamocortical brain oscillations during sleep that have been mechanistically linked to sleep-dependent memory consolidation in animal models and healthy controls. Sleep spindles are decreased in Rolandic epilepsy and related sleep-activated epileptic encephalopathies. We investigate the relationship between sleep spindle deficits and deficient sleep dependent memory consolidation in children with Rolandic epilepsy. MethodsIn this prospective case-control study, children were trained and tested on a validated probe of memory consolidation, the motor sequence task (MST). Sleep spindles were measured from high-density EEG during a 90-minute nap opportunity between MST training and testing using a validated automated detector. ResultsTwenty-three children with Rolandic epilepsy (14 with resolved disease), and 19 age- and sex-matched controls were enrolled. Children with active Rolandic epilepsy had decreased memory consolidation compared to control children (p=0.001, mean percentage reduction: 25.7%, 95% CI [10.3, 41.2]%) and compared to children with resolved Rolandic epilepsy (p=0.007, mean percentage reduction: 21.9%, 95% CI [6.2, 37.6]%). Children with active Rolandic epilepsy had decreased sleep spindle rates in the centrotemporal region compared to controls (p=0.008, mean decrease 2.5 spindles/min, 95% CI [0.7, 4.4] spindles/min). Spindle rate positively predicted sleep-dependent memory consolidation (p=0.004, mean MST improvement of 3.9%, 95% CI [1.3, 6.4]%, for each unit increase in spindles per minute). DiscussionChildren with Rolandic epilepsy have a sleep spindle deficit during the active period of disease which predicts deficits in sleep dependent memory consolidation. This finding provides a mechanism and noninvasive biomarker to aid diagnosis and therapeutic discovery for cognitive dysfunction in Rolandic epilepsy and related sleep activated epilepsy syndromes.

neuroscience↗