Neuronal Responses in Cat Primary Auditory Cortex to Electrical Cochlear Stimulation: IV. Activation Pattern for Sinusoidal Stimulation

2003 ◽  
Vol 89 (6) ◽  
pp. 3190-3204 ◽  
Author(s):  
Marcia W. Raggio ◽  
Christoph E. Schreiner
Keyword(s):  
Electrical Stimulation ◽  
Auditory Cortex ◽  
Primary Auditory Cortex ◽  
High Threshold ◽  
Threshold Behavior ◽  
Activation Pattern ◽  
Short Term ◽  
Low Threshold ◽  
Response Thresholds

Patterns of threshold distributions for single-cycle sinusoidal electrical stimulation and single pulse electrical stimulation were compared in primary auditory cortex of the adult cat. Furthermore, the effects of auditory deprivation on these distributions were evaluated and compared across three groups of adult cats. Threshold distributions for single and multiple unit responses from the middle cortical layers were obtained on the ectosylvian gyrus in an acutely implanted animal; 2 wk after deafening and implantation (short-term group); and neonatally deafened animals implanted following 2–5 yr of deafness (long-term group). For all three cases, we observed similar patterns of circumscribed regions of low response thresholds in the region of primary auditory cortex (AI). A dorsal and a ventral region of low response thresholds were found separated by a narrow, anterior-posterior strip of elevated thresholds. The ventral low-threshold regions in the short-term group were cochleotopically arranged. By contrast, the dorsal region in the short-term animals and both low-threshold regions in long-term deafened animals maintained only weak cochleotopicity. Analysis of the spatial extent of the low-threshold regions revealed that the activated area for sinusoidal stimulation was smaller and more circumscribed than for pulsatile stimulation for both dorsal and ventral AI. The width of the high-threshold ridge that separated the dorsal and ventral low-threshold regions was greater for sinusoidal stimulation. Sinusoidal and pulsatile threshold behavior differed significantly for electrode configurations with low and high minimum thresholds. Differences in threshold behavior and cortical response distributions between the sinusoidal and pulsatile stimulation suggest that stimulus shape plays a significant role in the activation of cortical activity. Differences in the activation pattern for short-term and long-term deafness reflect deafness-induced reorganizational changes based on factors such as differences in excitatory and inhibitory balance that are affected by the stimulation parameters.

Neuronal Responses in Cat Primary Auditory Cortex to Electrical Cochlear Stimulation. III. Activation Patterns in Short- and Long-Term Deafness

1999 ◽  
Vol 82 (6) ◽  
pp. 3506-3526 ◽  
Author(s):  
Marcia W. Raggio ◽  
Christoph E. Schreiner
Keyword(s):  
Auditory Cortex ◽  
Primary Auditory Cortex ◽  
Cortical Response ◽  
High Threshold ◽  
Short Term ◽  
Acute Group ◽  
Low Threshold ◽  
Response Thresholds ◽  
Adult Cat

The effects of auditory deprivation on the spatial distribution of cortical response thresholds to electrical stimulation of the adult cat cochlea were evaluated. Threshold distributions for single- and multiple-unit responses from the middle cortical layers were obtained on the ectosylvian gyrus in three groups of animals: adult, acutely implanted animals (“acute group”); adult animals, 2 wk after deafening and implantation (“short-term group”); adult, neonatally deafened animals (“long-term group”) implanted after 2–5 years of deafness. For all three groups, we observed similar patterns of circumscribed regions of low response thresholds in the region of primary auditory cortex (AI). A dorsal and a ventral region of low response thresholds were found separated by a narrow, anterior-posterior strip of elevated thresholds. The two low-threshold regions in the acute and the short-term group were arranged cochleotopically. This was reflected in a systematic shift of the cortical locations with minimum thresholds as a function of cochlear position of the radial and monopolar stimulation electrodes. By contrast, the long-term deafened animals maintained only weak or no signs of cochleotopicity. In some cases of this group, significant deviations from a simple tri-partition of the dorsoventral axis of AI was observed. Analysis of the spatial extent of the low-threshold regions revealed that the activated area in acute cases was significantly smaller than the long- and the short-term cases for both dorsal and ventral AI. There were no significant differences in the rostrocaudal extent of activation between long- and short-term deafening, although the total activated area in the short-term cases was larger than in long-term deafened animals. The width of the narrow high-threshold ridge that separated the dorsal and ventral low-threshold regions was the widest for the acute cases and the narrowest for the short-term deafened animals. The findings of relative large differences in cortical response distributions between the acute and short-term animals suggests that the effects observed in long-term deafened animals are not solely a consequence of loss of peripheral innervation density. The effects may reflect electrode-specific effects or reorganizational changes based on factors such as differences in excitatory and inhibitory balance.

Electrical stimulation of referred sensation area alleviates phantom limb pain

2021 ◽  
pp. 1-10
Author(s):  
Michihiro Osumi ◽  
Daisuke Shimizu ◽  
Yuki Nishi ◽  
Shu Morioka
Keyword(s):  
Electrical Stimulation ◽  
Single Case ◽  
Phantom Limb Pain ◽  
Phantom Limb ◽  
Long Term Effects ◽  
Limb Pain ◽  
Short Term ◽  
Analgesic Effects ◽  
Stimulation Of

Background: Patients with brachial plexus avulsion (BPA) usually experience phantom sensations and phantom limb pain (PLP) in the deafferented limb. It has been suggested that evoking the sensation of touch in the deafferented limb by stimulating referred sensation areas (RSAs) on the cheek or shoulder might alleviate PLP. However, feasible rehabilitation techniques using this approach have not been reported. Objective: The present study sought to examine the analgesic effects of simple electrical stimulation of RSAs in BPA patients with PLP. Methods: Study 1: Electrical stimulation of RSAs for 60 minutes was conducted for six BPA patients suffering from PLP to examine short-term analgesic effects. Study 2: A single case design experiment was conducted with two BPA patients to investigate whether electrical stimulation of RSAs was more effective for alleviating PLP than control electrical stimulation (electrical stimulation of sites on side opposite to the RSAs), and to elucidate the long-term effects of electrical stimulation of RSAs. Results: Study 1: Electrical stimulation of RSAs evoked phantom touch sensations in the deafferented limb, and significantly alleviated PLP (p <  0.05). Study 2: PLP was alleviated more after electrical stimulation on RSAs compared with control electrical stimulation (p <  0.05). However, the analgesic effects of electrical stimulation on RSAs were observed only in the short term, not in the long term (p >  0.05). Conclusions: Electrical stimulation of RSAs not only evoked phantom touch sensation but also alleviated PLP in the short term. The results indicate that electrical stimulation of RSAs may provide a useful practical rehabilitation technique for PLP. Future studies will be required to clarify the mechanisms underlying immediate PLP alleviation via electrical stimulation of RSAs.

scholarly journals Auditory-Cortex Short-Term Plasticity Induced by Selective Attention

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Iiro P. Jääskeläinen ◽  
Jyrki Ahveninen
Keyword(s):  
Selective Attention ◽  
Auditory Cortex ◽  
Receptive Fields ◽  
Discrimination Performance ◽  
Primary Auditory Cortex ◽  
Attentional Focus ◽  
Subcortical Structures ◽  
Short Term ◽  
Functional Changes ◽  
Short Term Plasticity

The ability to concentrate on relevant sounds in the acoustic environment is crucial for everyday function and communication. Converging lines of evidence suggests that transient functional changes in auditory-cortex neurons, “short-term plasticity”, might explain this fundamental function. Under conditions of strongly focused attention, enhanced processing of attended sounds can take place at very early latencies (~50 ms from sound onset) in primary auditory cortex and possibly even at earlier latencies in subcortical structures. More robust selective-attention short-term plasticity is manifested as modulation of responses peaking at ~100 ms from sound onset in functionally specialized nonprimary auditory-cortical areas by way of stimulus-specific reshaping of neuronal receptive fields that supports filtering of selectively attended sound features from task-irrelevant ones. Such effects have been shown to take effect in ~seconds following shifting of attentional focus. There are findings suggesting that the reshaping of neuronal receptive fields is even stronger at longer auditory-cortex response latencies (~300 ms from sound onset). These longer-latency short-term plasticity effects seem to build up more gradually, within tens of seconds after shifting the focus of attention. Importantly, some of the auditory-cortical short-term plasticity effects observed during selective attention predict enhancements in behaviorally measured sound discrimination performance.

scholarly journals The Role of Adaptation in Generating Monotonic Rate Codes in Auditory Cortex

2019 ◽  
Author(s):  
Jong Hoon Lee ◽  
Xiaoqin Wang ◽  
Daniel Bendor
Keyword(s):  
Auditory Cortex ◽  
Single Unit ◽  
Discharge Rate ◽  
Primary Auditory Cortex ◽  
Stimulus Presentation ◽  
Single Neurons ◽  
Short Term ◽  
Acoustic Stimuli ◽  
Biophysical Mechanism

AbstractIn primary auditory cortex, slowly repeated acoustic events are represented temporally by phase-locked activity of single neurons. Single-unit studies in awake marmosets (Callithrix jacchus) have shown that a sub-population of these neurons also monotonically increase or decrease their average discharge rate during stimulus presentation for higher repetition rates. Building on a computational single-neuron model that generates phase-locked responses with stimulus evoked excitation followed by strong inhibition, we find that stimulus-evoked short-term depression is sufficient to produce synchronized monotonic positive and negative responses to slowly repeated stimuli. By exploring model robustness and comparing it to other models for adaptation to such stimuli, we conclude that short-term depression best explains our observations in single-unit recordings in awake marmosets. Using this model, we emulated how single neurons could encode and decode multiple aspects of an acoustic stimuli with the monotonic positive and negative encoding of a given stimulus feature. Together, our results show that a simple biophysical mechanism in single neurons can allow a more complex encoding and decoding of acoustic stimuli.

EFFECT OF LONG-TERM EMOTIONALPAINFUL STRESS ON THE HISTONE H3 PHOSPHORYLATION IN THE MEDIAL PREFRONTAL CORTEX AND BASOLATERAL AMYGDALA OF RATS WITH GENETIC DIFFERENCES IN EXCITABILITY OF THE NERVOUS SYSTEM

2020 ◽  
pp. 27-33
Author(s):  
Наталья Алековна Дюжикова ◽  
Марина Борисовна Павлова ◽  
Анна Сергеевна Левина ◽  
Диана Азрет-Алиевна Хлебаева ◽  
Александр Иванович Вайдо
Keyword(s):  
Nervous System ◽  
Prefrontal Cortex ◽  
Basolateral Amygdala ◽  
Histone H3 ◽  
High Threshold ◽  
Rat Strains ◽  
H3 Phosphorylation ◽  
Low Threshold ◽  
Histone H3 Phosphorylation

Цель - исследование влияния длительного эмоционально-болевого стрессорного воздействия (ДЭБС) в разные сроки после его окончания (24 ч, 2 нед, 2 мес) на фосфорилирование гистона Н3 (по серину 10) (phH3-Ser10) в клетках медиальной префронтальной коры (мПК) и базолатеральной области амигдалы (блА) у крыс двух линий с разным порогом возбудимости нервной системы к электрическому току (генетическая модель постстрессорных тревожно-депрессивных расстройств). Материал и методы. С использованием иммуногистохимического метода исследована иммунореактивность клеток мПК и блА к phH3-Ser10 у крыс 2 селекционных линий: низковозбудимых с высоким порогом возбудимости нервной системы (линия ВП) и высоковозбудимых с низким порогом возбудимости (линия НП). В качестве стрессора применяли длительное (15 сут) эмоционально-болевое воздействие по схеме К. Гехта. Результаты. У низковозбудимых крыс линии ВП в блА обнаружен более высокий базовый уровень phH3-Ser10 по сравнению с высоковозбудимыми крысами линии НП. В мПК межлинейных различий в базовом уровне phH3-Ser10 не обнаружено. Выявлено влияние ДЭБС на уровень phH3-Ser10 у крыс обеих линий. Показано кратковременное (через 24 ч) повышение phH3-Ser10 в мПК у крыс линии НП и устойчивое (до 2 мес после ДЭБС) у животных линии ВП. В блА только у высоковозбудимых крыс линии НП обнаружено индуцируемое ДЭБС возрастание и устойчивое до 2 мес сохранение уровня phH3-Ser10. Выводы. Выявлены долговременные изменения фосфорилирования гистона Н3, имеющие структурную специфичность и зависящие от генетически детерминированного функционального состояния нервной системы крыс. Objective - to study the effect of the long-term emotional-painful stress on the level of histone H3 phosphorylation at Ser10 (phH3-Ser10) in the medial prefrontal cortex (mPC) and basolateral amygdala (BLA) in the rats of two strains characterized by different excitability of the nervous system in normal conditions and at various intervals (24 hours, 2 weeks, 2 months) after the long-term emotional-painful stress (LEPS). Material and methods. The immunoreactivity of mPC and BLA cells to phH3-Ser10 was studied using the immunohistochemical method. The objects of investigation were selected rat strains: НТ (high threshold, low excitability of the nervous system) and LT (low threshold, high excitability of the nervous system). A long-term (15 days) exposure to emotional-painful stress according to K. Hecht’s scheme was used. Results. Intact rats with low nervous excitability (HT strain - high threshold) demonstrated more high basal level of phH3Ser10 in BLA cells than rats with high excitability (LT strain - low threshold). No differences in basal level of phH3-Ser10 between two rat strains were found. The exposure to emotional- painful stress caused alterations in the level of phH3-Ser10 in rats from both strains. Increase of phH3-Ser10 level in the mPC was short-term (24h after LEPS) in LT rats and long-term (up to 2 months) in HT rats. The long-term (up to 2 months) increase of phH3-Ser10 level after stress in the BLA was discovered in LT rats only. Conclusions. Long-term changes in histone H3 phosphorylation, which have structural specificity and depend on genetically determined functional state of rats nervous system, were revealed.

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