Is Spontaneous High-Voltage Rhythmic Spike Discharge in Long Evans Rats an Absence-Like Seizure Activity?

2004 ◽  
Vol 91 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Fu-Zen Shaw
Keyword(s):  
High Voltage ◽  
Slow Wave Sleep ◽  
Seizure Activity ◽  
Spectral Characteristics ◽  
Absence Seizure ◽  
Mu Rhythm ◽  
Behavioral Arousal ◽  
Ongoing Behavior ◽  
Long Evans ◽  
Electrical Stimuli

A distinct high-voltage rhythmic spike (HVRS) discharge characterized by a barrage of negative spikes oscillating at 5–12 Hz was observed in chronically implanted Long Evans rats. Spontaneous HVRS discharges were exhibited in 90% of 40 Long Evans rats and occurred during sudden arrest of ongoing behavior (immobility) with occasional facial/whisker twitching. However, the function of HVRS discharges in Long Evans rats remains inconclusive to date and has been associated with alpha tremor/mu rhythm, attentive mu wave, and absence seizure. To elucidate the function of HVRS discharges in Long Evans rats, several experiments were performed. In a 6-h recording session (12:00–18:00), HVRS activities primarily occurred in several specific vigilance states, being particularly abundant in a short-lasting period before vigilance changes. Several characteristics, such as durations, oscillatory frequencies, and interspike intervals (ISIs) of HVRS discharges, were altered during wake-sleep states. Oscillatory frequencies were negatively correlated with durations of HVRS segments. In addition, ISIs of a HVRS episode exhibited a crescendo-decrescendo pattern. These variable ISIs could explain why a negative correlation was found between oscillatory frequencies and durations of HVRS episodes. Moreover, HVRS discharges were demonstrated to have widespread and near-synchronous distribution to bilateral cortical areas. In addition, innocuous electrical stimuli were unable to stop ongoing HVRS discharges. By contrast, noxious stimuli elicited behavioral arousal and immediately terminated most HVRS discharges. Cortical-evoked potentials in response to mild electrical stimulation under HVRS discharges were different from those under waking state but resemble those under slow-wave sleep with a smaller magnitude. Moreover, the temporal and spectral characteristics of spontaneous HVRS activities were analogous to those of seizure activities induced by penicillin and pentylenetetrazol. The incidence of spontaneous HVRS discharges was significantly decreased by ethosuximide administration. Based on these results, HVRS discharge might not be associated with a voluntary mu-rhythm behavior, instead it behaves as an absence-like seizure activity. These results were also collaborated using other genetic absence-seizure rats, such as WAG/Rij and GAERS rats. Possible mechanisms for the generation and termination of paroxysmal HVRS discharges are also discussed.

7-12 Hz High-Voltage Rhythmic Spike Discharges in Rats Evaluated by Antiepileptic Drugs and Flicker Stimulation

2007 ◽  
Vol 97 (1) ◽  
pp. 238-247 ◽  
Author(s):  
Fu-Zen Shaw
Keyword(s):  
Antiepileptic Drugs ◽  
High Voltage ◽  
Wistar Rats ◽  
Barrel Cortex ◽  
Occipital Cortex ◽  
High Dose ◽  
Absence Seizure ◽  
Mu Rhythm ◽  
Flicker Stimulation ◽  
Long Evans

Paroxysmal 7- to 12-Hz high-voltage rhythmic spike (HVRS) or spike-wave discharges often appear in several particular strains of rats. However, functional hypotheses of these 7-12 Hz high-voltage cortical oscillations (absence seizure vs. idling mu rhythm) are inconclusive. The mu rhythm can be provoked by flicker stimulation (FS) in most people, but FS is less effective at eliciting absence epileptic activity. Therefore FS and antiepileptic drugs were used to verify the role of HVRS activity in Long-Evans rats with spontaneous HVRS discharges and Wistar rats without spontaneous HVRS discharges. The occurrence of HVRS discharges was significantly reduced by antiabsence drugs (ethosuximide, valproic acid, and diazepam) in dose-dependent manners, but high-dose carbamazepine displayed little effect. On the other hand, oscillation frequencies and durations of spontaneous HVRS discharges were not altered by FS. Under asynchronous brain activity, many FSs (>60%) elicited small-amplitude mu-rhythm-like activity in the barrel cortex concomitant with FS-related rhythms in the occipital cortex and resulted in significant augmentation of 7-12 Hz power in the parietal region. Furthermore, a large portion of FSs (>60%) revealed increase of 7-12 Hz power of the parietal cortex after ethosuximide administration (100 mg/kg ip) in Long-Evans rats. Similar FS-elicited phenomena also appeared in Wistar rats. Characteristics of FS-elicited mu-rhythm-like activities were consistent with those observed in humans, and they remarkably differed from those of spontaneous HVRS discharges. These results support the hypothesis that HVRS activity in Long-Evans rats may be an absence-like seizure activity rather than the mu rhythm.

Relation Between Activities of the Cortex and Vibrissae Muscles During High-Voltage Rhythmic Spike Discharges in Rats

2005 ◽  
Vol 93 (5) ◽  
pp. 2435-2448 ◽  
Author(s):  
Fu-Zen Shaw ◽  
Yi-Fang Liao
Keyword(s):  
High Voltage ◽  
Muscle Activity ◽  
Oscillation Frequency ◽  
Muscular Activity ◽  
Simultaneous Recording ◽  
Absence Seizure ◽  
Mu Rhythm ◽  
Oscillation Frequencies ◽  
Peripheral Sensory

Paroxysmal 5- to 12-Hz high-voltage rhythmic spike (HVRS) activities, which are accompanied by whisker twitching (WT), are found in Long Evans rats, but the function of these HVRS activities is still debated. In four major functional hypotheses of HVRS discharges, i.e., alpha tremor, attention/mu rhythm, idling/mu rhythm, and absence seizure, the first two hypotheses emphasize WT behavior in HVRS bouts. Whisker movement is primarily determined by activation of intrinsic and extrinsic muscles. To clarify the role of WT in HVRS activities, simultaneous recording of the activities from the cortex and intrinsic/extrinsic and neck muscles were performed. Most HVRS bouts (68.8%) revealed no time-locked WT behavior in a 2-h recording session. In addition, WT primarily arose from active protraction due to activation of intrinsic muscles followed by passive retraction. A small portion of WT resulted from activation of both vibrissae muscles with dynamic frequency-dependent phase shifts. Onset of the rhythmic vibrissae EMG significantly lagged behind HVRS onset, and the mean duration of vibrissae muscle activity was one-third to a one-half of a HVRS bout. Moreover, a greater number of HVRS bouts were associated with a longer HVRS duration and higher oscillation frequency. Oscillation frequencies of HVRS activities without WT behavior were significantly lower than those with WT. Under peripheral sensory/motor blockade by xylocaine injection, oscillation frequencies of HVRS bouts significantly decreased, but no remarkable changes in the number or duration of HVRS bouts were observed. Compared with vibrissa muscle activity during WT and exploratory whisking, the duration of muscular activity in each cycle was apparently longer during whisking bouts. Based on these results, overemphasis of the role of WT on HVRS activities might not be appropriate. Instead, HVRS discharges may be associated with absence seizure or idling state. In addition, peripheral inputs, including WT, may elevate the oscillation frequency of HVRS bouts. Moreover, different muscular controls may exist between WT and whisking.

Mozart K.448 attenuates spontaneous absence seizure and related high-voltage rhythmic spike discharges in Long Evans rats

2013 ◽  
Vol 104 (3) ◽  
pp. 234-240 ◽  
Author(s):  
Lung-Chang Lin ◽  
Chun-Ting Juan ◽  
Hsueh-Wen Chang ◽  
Ching-Tai Chiang ◽  
Ruey-Chang Wei ◽  
...  
Keyword(s):  
High Voltage ◽  
Absence Seizure ◽  
Long Evans

Neuroanatomical, neurochemical, and neurophysiological bases of waking and sleeping

2017 ◽  
Author(s):  
Barbara E. Jones
Keyword(s):  
Slow Wave Sleep ◽  
Muscle Tone ◽  
Paradoxical Sleep ◽  
Cortical Activity ◽  
Cortical Activation ◽  
Behavioral Arousal ◽  
Distinct Cell ◽  
Cell Groups ◽  
Descending Influences ◽  
And Behavior

Neurons distributed through the reticular core of the brainstem, hypothalamus, and basal forebrain and giving rise to ascending projections to the cortex or descending projections to the spinal cord promote the changes in cortical activity and behavior that underlie the sleep–wake cycle and three states of waking, NREM (slow wave) sleep, and REM (paradoxical) sleep. Forming the basic units of these systems, glutamate and GABA cell groups are heterogeneous in discharge profiles and projections, such that different subgroups can promote cortical activation (wake/REM(PS)-active) versus cortical deactivation (NREM(SWS)-active) by ascending influences or behavioral arousal with muscle tone (wake-active) versus behavioral quiescence with muscle atonia (NREM/REM(PS)-active) by descending influences. These different groups are in turn regulated by neuromodulatory systems, including cortical activation (wake/REM(PS)-active acetylcholine neurons), behavioral arousal (wake-active noradrenaline, histamine, serotonin, and orexin neurons), and behavioral quiescence (NREM/REM(PS)-active MCH neurons). By different projections, chemical neurotransmitters and discharge profiles, distinct cell groups thus act and interact to promote cyclic oscillations in cortical activity and behavior forming the sleep-wake cycle and states.

Audiogenic seizure activity following HSV-1 GAD65 sense or antisense injection into inferior colliculus of Long–Evans rat

2017 ◽  
Vol 71 ◽  
pp. 238-242
Author(s):  
James R. Coleman ◽  
Karen C. Thompson ◽  
Marlene A. Wilson ◽  
Steven P. Wilson
Keyword(s):  
Inferior Colliculus ◽  
Seizure Activity ◽  
Audiogenic Seizure ◽  
Long Evans ◽  
Hsv 1

Temporal changes in growth hormone, cortisol, and glucose: relation to light onset and behavior

1975 ◽  
Vol 229 (2) ◽  
pp. 409-415 ◽  
Author(s):  
BH Natelson ◽  
J Holaday ◽  
J Meyerhoff ◽  
PE Stokes
Keyword(s):  
Growth Hormone ◽  
Light Cycle ◽  
Behavioral Arousal ◽  
Plasma Growth Hormone ◽  
Dark Cycle ◽  
Gh Secretion ◽  
Ongoing Behavior ◽  
Traditional Assumption ◽  
Episodic Fluctuations ◽  
And Behavior

Plasma growth hormone (GH), cortisol, and glucose were measured every 20 min in the last 2 h of a 12-h dark cycle and the first 4 h of a 12-h light cycle in eight environmentally limited rhesus monkeys; additionally, ongoing behavior was scored every 20 min in the last 4 h when the lights in the booths housing the monkeys were on. Episodic fluctuations in levels of GH, cortisol, and glucose occurred. Onset of booth illumination was associated with a significant number of GH secretory bursts (6 of 18), and more than twice as many bursts per hour occurred in the light than in the dark (L:D = 0.44:0.19). The onset of illumination was also associated with significant increases in glucose for the eight animals. In addition, plasma glucose increased concurrently with the onset of 13 of 18 bursts of GH secretion. Monkeys were rated as significantly more alert or aroused when plasma levels of GH and glucose were increasing than when they were decreasing. In contrast plasma cortisol showed small, rhythmic fluctuations over time that did not correlate with booth illumination or degree of behavioral arousal. This latter finding challenges the traditional assumption that cortisol is a sensitive index of behavioral arousal.

Sleep-promoting material from human urine and its relation to factor S from brain

1980 ◽  
Vol 238 (2) ◽  
pp. E116-E123
Author(s):  
J. M. Krueger ◽  
J. Bacsik ◽  
J. Garcia-Arraras
Keyword(s):  
Ion Exchange ◽  
Slow Wave ◽  
High Voltage ◽  
Human Urine ◽  
Time Course ◽  
Slow Wave Sleep ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Intraventricular Infusion ◽  
High Voltage Electrophoresis

A sleep-promoting factor was extracted from human urine. Intraventricular infusion of the purified material induced excess slow-wave sleep in rats and rabbits for 5--10 h after the infusion. Chemical properties of the urinary factor were similar to those of factor S derived from whole brains of sleep-deprived goats, sheep, and rabbits. The behavior of the urinary factor in two ion exchange chromatographic steps, high voltage electrophoresis, gel-filtration, and ultrafiltration was similar to that of factor S. Effects of the purified urinary factor on slow-wave sleep of rats and rabbits were similar in time-course and duration to those of factor S from brain. However, the factor obtained from human urine did not increase the amplitude of cortical slow waves to the same extent as did factor S from brains of sleep-deprived animals.

Low-Probability Transmission of Neocortical and Entorhinal Impulses Through the Perirhinal Cortex

2004 ◽  
Vol 91 (5) ◽  
pp. 2079-2089 ◽  
Author(s):  
Joe Guillaume Pelletier ◽  
John Apergis ◽  
Denis Paré
Keyword(s):  
Hippocampal Neurons ◽  
Slow Wave Sleep ◽  
Time Window ◽  
Activity Patterns ◽  
Perirhinal Cortex ◽  
Sharp Waves ◽  
Low Probability ◽  
Unanesthetized Animals ◽  
Artificial Nature ◽  
Electrical Stimuli

One model of episodic memory posits that during slow-wave sleep (SWS), the synchronized discharges of hippocampal neurons in relation to sharp waves “replay” activity patterns that occurred during the waking state, facilitating synaptic plasticity in the neocortex. Although evidence of replay was found in the hippocampus in relation to sharp waves, it was never shown that this activity reached the neocortex. Instead, it was assumed that the rhinal cortices faithfully transmit information from the hippocampus to the neocortex and reciprocally. Here, we tested this idea using 3 different approaches. 1) Stimulating electrodes were inserted in the entorhinal cortex and temporal neocortex and evoked unit responses were recorded in between them, in the intervening rhinal cortices. In these conditions, impulse transfer occurred with an extremely low probability, in both directions. 2) To rule out the possibility that this unreliable transmission resulted from the artificial nature of electrical stimuli, crosscorrelation analyses of spontaneous neocortical, perirhinal, and entorhinal firing were performed in unanesthetized animals during the states of waking and SWS. Again, little evidence of propagation could be obtained in either state. 3) To test the idea that propagation occurs only when large groups of neurons are activated within a narrow time window, we computed perievent histograms of neocortical, perirhinal, and entorhinal neuronal discharges around large-amplitude sharp waves. However, these synchronized entorhinal discharges also failed to propagate across the perirhinal cortex. These findings suggest that the rhinal cortices are more than a relay between the neocortex and hippocampus, but rather a gate whose properties remain to be identified.

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