#شناسایی #سازوکارهای بالقوه ایجاد #الکلیزم
#Dopamine #Neurons #Change the #Type of #Excitability in #Response to #Stimuli
#پژوهشگران مدرسه عالی اقتصاد روسیه با همکاری موسسه ملی سلامت و وزارت آموزش روسیه 🇷🇺، دانشکده نرمال سوپریر فرانسه 🇫🇷، و دانشگاه ایندیانای ایالات متحده 🇺🇸، در پژوهش بر ریشه های #عصبی، #ژنتیک و #متابولیک #الکلیزم در افراد دریافتند که مکانیزم های #تغییریافته عمل در پاسخ #نورون های #دوپامینرژیک در پویایی های #کرتکس #پیش_پیشانی منجر به تغییر سطح #دوپامین مغز شده و فرد را به سمت الکلیزم سوق دهند.
Abstract
#The #dynamics of #neuronal #excitability #determine the #neuron’s response to stimuli, its #synchronization and #resonance properties and, ultimately, the computations it performs in the #brain. We investigated the dynamical #mechanisms underlying the excitability type of dopamine (#DA) neurons, using a #conductance-based #biophysical model, and its #regulation by intrinsic and #synaptic currents. #Calibrating the model to reproduce low frequency #tonic firing results in #N-methyl-D-aspartate (#NMDA) #excitation balanced by γ-Aminobutyric acid (#GABA)-mediated #inhibition and leads to type I excitable behavior characterized by a continuous decrease in firing frequency in response to #hyperpolarizing currents. Furthermore, we analyzed how excitability type of the DA neuron model is influenced by changes in the intrinsic current composition. A #subthreshold #sodium current is necessary for a continuous frequency decrease during application of a negative current, and the low-frequency “balanced” state during simultaneous activation of NMDA and GABA #receptors. Blocking this current switches the neuron to type II characterized by the abrupt onset of repetitive firing. Enhancing the #anomalous rectifier #Ih current also switches the excitability to type II. Key characteristics of synaptic conductances that may be observed in vivo also change the type of excitability: a #depolarized γ-Aminobutyric acid receptor (#GABAR) reversal potential or co-activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (#AMPARs) leads to an abrupt frequency drop to zero, which is typical for type II excitability. Coactivation of N-methyl-D-aspartate receptors (#NMDARs) together with AMPARs and GABARs shifts the type I/II boundary toward more hyperpolarized GABAR reversal potentials. To better understand how altering each of the aforementioned currents leads to changes in excitability profile of DA neuron, we provide a thorough dynamical analysis. Collectively, these results imply that type I excitability in dopamine neurons might be important for low firing rates and fine-tuning basal dopamine levels, while switching excitability to type II during NMDAR and AMPAR activation may facilitate a transient increase in dopamine concentration, as type II neurons are more amenable to synchronization by mutual excitation.
لینک منبع 👇🏻(further reading)👇🏻
journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1005233
✅(در صورت جذابیت و علاقمندی به موضوع، مطلب را برای دیگران نیز بازنشر فرمایید).
📢کانال #دکترامیرمحمدشهسوارانی
🍃🌹🌸💐🌸🌹🍃
@DrAmirMohammadShahsavarani
#Dopamine #Neurons #Change the #Type of #Excitability in #Response to #Stimuli
#پژوهشگران مدرسه عالی اقتصاد روسیه با همکاری موسسه ملی سلامت و وزارت آموزش روسیه 🇷🇺، دانشکده نرمال سوپریر فرانسه 🇫🇷، و دانشگاه ایندیانای ایالات متحده 🇺🇸، در پژوهش بر ریشه های #عصبی، #ژنتیک و #متابولیک #الکلیزم در افراد دریافتند که مکانیزم های #تغییریافته عمل در پاسخ #نورون های #دوپامینرژیک در پویایی های #کرتکس #پیش_پیشانی منجر به تغییر سطح #دوپامین مغز شده و فرد را به سمت الکلیزم سوق دهند.
Abstract
#The #dynamics of #neuronal #excitability #determine the #neuron’s response to stimuli, its #synchronization and #resonance properties and, ultimately, the computations it performs in the #brain. We investigated the dynamical #mechanisms underlying the excitability type of dopamine (#DA) neurons, using a #conductance-based #biophysical model, and its #regulation by intrinsic and #synaptic currents. #Calibrating the model to reproduce low frequency #tonic firing results in #N-methyl-D-aspartate (#NMDA) #excitation balanced by γ-Aminobutyric acid (#GABA)-mediated #inhibition and leads to type I excitable behavior characterized by a continuous decrease in firing frequency in response to #hyperpolarizing currents. Furthermore, we analyzed how excitability type of the DA neuron model is influenced by changes in the intrinsic current composition. A #subthreshold #sodium current is necessary for a continuous frequency decrease during application of a negative current, and the low-frequency “balanced” state during simultaneous activation of NMDA and GABA #receptors. Blocking this current switches the neuron to type II characterized by the abrupt onset of repetitive firing. Enhancing the #anomalous rectifier #Ih current also switches the excitability to type II. Key characteristics of synaptic conductances that may be observed in vivo also change the type of excitability: a #depolarized γ-Aminobutyric acid receptor (#GABAR) reversal potential or co-activation of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (#AMPARs) leads to an abrupt frequency drop to zero, which is typical for type II excitability. Coactivation of N-methyl-D-aspartate receptors (#NMDARs) together with AMPARs and GABARs shifts the type I/II boundary toward more hyperpolarized GABAR reversal potentials. To better understand how altering each of the aforementioned currents leads to changes in excitability profile of DA neuron, we provide a thorough dynamical analysis. Collectively, these results imply that type I excitability in dopamine neurons might be important for low firing rates and fine-tuning basal dopamine levels, while switching excitability to type II during NMDAR and AMPAR activation may facilitate a transient increase in dopamine concentration, as type II neurons are more amenable to synchronization by mutual excitation.
لینک منبع 👇🏻(further reading)👇🏻
journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1005233
✅(در صورت جذابیت و علاقمندی به موضوع، مطلب را برای دیگران نیز بازنشر فرمایید).
📢کانال #دکترامیرمحمدشهسوارانی
🍃🌹🌸💐🌸🌹🍃
@DrAmirMohammadShahsavarani
journals.plos.org
Dopamine Neurons Change the Type of Excitability in Response to Stimuli
Author Summary Dopamine neurons play a central role in guiding motivated behaviors. However, complete understanding of computations these neurons perform to encode rewarding and salient stimuli is still forthcoming. Network connectivity influences neural…
♻️#هیجان و #بویایی: #آلکسی_تیمیا منجر به تغییر در #پردازش بویایی می شود.
#Alexithymia and #emotional #reactions to #odors
پژوهش های محققان نورساینس مرکز نوروساینس تریسته 🇮🇹، دانشگاه گراتز 🇦🇹، و دانشگاه رم 🇮🇹 مشخص ساخته است که پردازش های هیجانی تاثیر بسیار زیادی بر نحوه بویایی و واکنش افراد به بوهای مختلف دارند.
🔬در این پژوهش که بر 502 نفر داوطلب سالم انجام شد، افراد حسب نمرات آلکسی تیمیا به سه گروه آلکسی تیمیای شدید (HA)، آلکسی تیمیای متوسط (MA)، و آلکسی تیمیای خفیف (LA) تقسیم شدند. برای بویایی، افراد مورد ارزیابی توسط آزمون های اختصاصی بویایی قرار گرفتند. همچنین، شاخص های مختلف #شناختی، #روانی، و #فیزیولوژیک داوطلبان نیز سنجیده شد.
📚نتایج نشان دادند که افراد دارای آلکسی تیمیا در واکنش به #بو پاسخ های متفاوتی از افراد #غیرآلکسیتیمیک دارند. همچنین، مولفه های مختلف آلکسی تیمیا با ابعاد مختلفی از عملکرد بویایی، پاسخ های روانی-فیزولوژیک به #بوها، و زمان واکنش (#RT) در #آزمونهای #بوسنجی در ارتباطند.
Abstract
#Alexithymia is a #psychological #construct characterized by #deficits in #processing #emotional #stimuli. However, little is known about the processing of #odours in alexithymia, even though there is extensive proof that emotion and #olfaction are closely linked. The present study is aimed at investigating how #alexithymic individuals process emotions conveyed by odors. Emotional responses to unpleasant, neutral odors and clean air were collected through self-report ratings and psychophysiological measures in a sample of 62 healthy participants with high (HA), medium (MA) and low (LA) levels of alexithymia. Moreover, participants performed tests on odors #identification and #threshold and completed questionnaires assessing olfactory #imagery and #awareness. Two main results have been found: first, HA and MA groups showed altered #physiological responses to odors, compared to LA, while no differences among the groups were observed in odor ratings; and second, #affective and #cognitive alexithymia components were differently associated with the performance on olfactory tests, #skin #conductance response to odors, #reaction #times in the rating task, and scores on olfactory questionnaires. We conclude that alexithymia is characterized by altered physiological reactions to olfactory stimuli; moreover, we stress the importance of evaluating the different alexithymia components since they affect emotional stimuli processing in different ways.
لینک منبع 👇🏻(further reading)👇🏻
http://neurosciencenews.com/alexithymia-olfaction-emotion-7826/
✅(در صورت جذابیت و علاقمندی به موضوع، مطلب را برای دیگران نیز بازنشر فرمایید).
📢کانال #دکترامیرمحمدشهسوارانی
🍃🌹🌸💐🌸🌹🍃
@DrAmirMohammadShahsavarani
#Alexithymia and #emotional #reactions to #odors
پژوهش های محققان نورساینس مرکز نوروساینس تریسته 🇮🇹، دانشگاه گراتز 🇦🇹، و دانشگاه رم 🇮🇹 مشخص ساخته است که پردازش های هیجانی تاثیر بسیار زیادی بر نحوه بویایی و واکنش افراد به بوهای مختلف دارند.
🔬در این پژوهش که بر 502 نفر داوطلب سالم انجام شد، افراد حسب نمرات آلکسی تیمیا به سه گروه آلکسی تیمیای شدید (HA)، آلکسی تیمیای متوسط (MA)، و آلکسی تیمیای خفیف (LA) تقسیم شدند. برای بویایی، افراد مورد ارزیابی توسط آزمون های اختصاصی بویایی قرار گرفتند. همچنین، شاخص های مختلف #شناختی، #روانی، و #فیزیولوژیک داوطلبان نیز سنجیده شد.
📚نتایج نشان دادند که افراد دارای آلکسی تیمیا در واکنش به #بو پاسخ های متفاوتی از افراد #غیرآلکسیتیمیک دارند. همچنین، مولفه های مختلف آلکسی تیمیا با ابعاد مختلفی از عملکرد بویایی، پاسخ های روانی-فیزولوژیک به #بوها، و زمان واکنش (#RT) در #آزمونهای #بوسنجی در ارتباطند.
Abstract
#Alexithymia is a #psychological #construct characterized by #deficits in #processing #emotional #stimuli. However, little is known about the processing of #odours in alexithymia, even though there is extensive proof that emotion and #olfaction are closely linked. The present study is aimed at investigating how #alexithymic individuals process emotions conveyed by odors. Emotional responses to unpleasant, neutral odors and clean air were collected through self-report ratings and psychophysiological measures in a sample of 62 healthy participants with high (HA), medium (MA) and low (LA) levels of alexithymia. Moreover, participants performed tests on odors #identification and #threshold and completed questionnaires assessing olfactory #imagery and #awareness. Two main results have been found: first, HA and MA groups showed altered #physiological responses to odors, compared to LA, while no differences among the groups were observed in odor ratings; and second, #affective and #cognitive alexithymia components were differently associated with the performance on olfactory tests, #skin #conductance response to odors, #reaction #times in the rating task, and scores on olfactory questionnaires. We conclude that alexithymia is characterized by altered physiological reactions to olfactory stimuli; moreover, we stress the importance of evaluating the different alexithymia components since they affect emotional stimuli processing in different ways.
لینک منبع 👇🏻(further reading)👇🏻
http://neurosciencenews.com/alexithymia-olfaction-emotion-7826/
✅(در صورت جذابیت و علاقمندی به موضوع، مطلب را برای دیگران نیز بازنشر فرمایید).
📢کانال #دکترامیرمحمدشهسوارانی
🍃🌹🌸💐🌸🌹🍃
@DrAmirMohammadShahsavarani
Neuroscience News
What the Nose Reveals About Our Relationship With Emotions
Those with alexithymia, a psychological condition in which people have difficulty in the emotions they are experiencing, may also have an altered physiological response to olfactory stimulation, researchers report.