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I. V. Pavlova - One of the best experts on this subject based on the ideXlab platform.
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Effects of Microinjections of a Serotonin Receptor (5-HT_2A/C) Agonist and Antagonist into the Amygdala in Rats on Anxiety Behavior and Conditioned Reflex Fear
Neuroscience and Behavioral Physiology, 2020Co-Authors: I. V. Pavlova, N. D. Broshevitskaya, M P RysakovaAbstract:The role of 5-HT_2A/C receptors in the amygdala in the acquisition, testing, and extinction of Conditioned Reflex fear and on anxiety behavior was studied. Microinjections of a receptor antagonist (ketanserin, 0.5 μg/0.5 μl) into the basolateral nucleus of the amygdala decreased signs of Conditioned Reflex fear in the form of freezing and prevented reacquisition, but had no effect on anxiety behavior in rats. Administration of an agonist (DOI, 1 μg/0.5 μl) led to an increase in movement activity, panic-like behavior, and decreased anxiety, with reductions in the signs of fear in the form of freezing. Both the agonist and the antagonist of 5-HT_2A/C receptors were able to accelerate fear extinction in rats with prolonged freezing, which does not extinguish easily. These results provide evidence that 5-HT_2A/C receptors in the amygdala play a significant role in the occurrence and persistence of Conditioned Reflex fear apparent as freezing.
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Conditioned Reflex Reactions in High-Impulsivity Rats Are Weaker than Those in Low-Impulsivity Animals
Neuroscience and Behavioral Physiology, 2020Co-Authors: I. V. Pavlova, M. I. Zaichenko, G. K. Merzhanova, G. A. GrigoryanAbstract:The delay discounting procedure was used to classify rats into high-impulsivity (preferring low-value immediate food reinforcement) and low-impulsivity (choosing a high-value reinforcement with a 5-sec delay), as well as ambivalent animals, which did not display any preference for reinforcement choice. In high-impulsivity rats, the Conditioned fear reaction assessed in terms of freezing reactions was less intense than in low-impulsivity and ambivalent rats. Between-group differences were apparent at the training stage and on testing the Reflex 24 h after training. Differences were seen both on exposure to the signal stimulus (a sound) and on exploration of the context. Extinction of the Conditioned Reflex fear reaction in high-impulsivity rats occurred more quickly than in low-impulsivity and ambivalent animals. Pain reaction thresholds (twitching and jumping) were no different in the three groups of animals. The results are assessed in relation to concepts of the functional and dysfunctional forms of impulsivity and their corresponding manifestations of Conditioned Reflex fear and negative affective disorders.
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behavior of rats with high and low levels of freezing in defensive situations and on selection of food reinforcement
Neuroscience and Behavioral Physiology, 2020Co-Authors: I. V. Pavlova, Maria P Rysakova, Maria Zaichenko, N. D. BroshevitskayaAbstract:Behavior in rats with different levels of freezing in a classical defensive Conditioned Reflex was compared on acquisition of Conditioned passive and active avoidance Reflexes and on selection of food reinforcement of different values. Rats with prolonged freezing acquired the passive avoidance Reflex better and retained it longer during extinction than animals with shorter freezing. At the same time, the active avoidance Reflex in the shuttle box was acquired more easily by animals with short periods of freezing. Rats with prolonged freezing preferred a delayed and more valuable reinforcement in the model of choosing food reinforcements of different values (low level of impulsivity), while animals with short freezing preferred the low-value reinforcement without a delay (high level of impulsivity). The thresholds of pain sensitivity were no different in rats of the different groups. Thus, rats with prolonged freezing demonstrated a passive behavioral strategy in defensive situations and a low level of impulsivity, while rats with short freezing used an active behavioral strategy and showed a high level of impulsivity.
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the role of β1 2 adrenoceptors in the amygdala in the behavior of rats with different levels of freezing in Conditioned Reflex fear
Neuroscience and Behavioral Physiology, 2019Co-Authors: I. V. Pavlova, M P RysakovaAbstract:Individual sensitivity to blockade of β1,2-adrenoceptors was studied by dividing rats into groups depending on the manifestation of Conditioned Reflex fear in a classical defensive Conditioned Reflex (low- and high-freezing animals) and on the level of anxiety in the elevated plus maze and dark-light box tests (highand low-anxiety animals). The effects due to local administration of the β1,2-adrenoceptor antagonist propranolol (1.25 μg/0.5 μl) and physiological saline (controls, 0.5 μl) into the basolateral amygdala were compared in the different groups of rats. Administration of propranolol into the amygdala before testing of previously acquired Conditioned Reflex fear led to a decrease in freezing time in response to the Conditioned signal only in low-freezing animals, but not in high-freezing animals. Administration of propranolol into the amygdala accelerated extinction and degraded the productivity of retraining in high-freezing rats, having virtually no effect on low-freezing animals. In addition, administration of propranolol into the amygdala did not induce any significant changes in measures of anxiety in these tests in either high- or low-anxiety rats. A difference in the sensitivity of high- and low-freezing rats to injections of propranolol into the amygdala was seen. Amygdalar β1,2-adrenoceptors play a significant role in the acquisition and extinction of Conditioned Reflex fear in high-freezing rats, facilitating the appearance of prolonged freezing and resistance to extinction of the Reflex.
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The Role of β_1,2-Adrenoceptors in the Amygdala in the Behavior of Rats with Different Levels of Freezing in Conditioned Reflex Fear
Neuroscience and Behavioral Physiology, 2019Co-Authors: I. V. Pavlova, M P RysakovaAbstract:Individual sensitivity to blockade of β_1,2-adrenoceptors was studied by dividing rats into groups depending on the manifestation of Conditioned Reflex fear in a classical defensive Conditioned Reflex (low- and high-freezing animals) and on the level of anxiety in the elevated plus maze and dark-light box tests (highand low-anxiety animals). The effects due to local administration of the β_1,2-adrenoceptor antagonist propranolol (1.25 μg/0.5 μl) and physiological saline (controls, 0.5 μl) into the basolateral amygdala were compared in the different groups of rats. Administration of propranolol into the amygdala before testing of previously acquired Conditioned Reflex fear led to a decrease in freezing time in response to the Conditioned signal only in low-freezing animals, but not in high-freezing animals. Administration of propranolol into the amygdala accelerated extinction and degraded the productivity of retraining in high-freezing rats, having virtually no effect on low-freezing animals. In addition, administration of propranolol into the amygdala did not induce any significant changes in measures of anxiety in these tests in either high- or low-anxiety rats. A difference in the sensitivity of high- and low-freezing rats to injections of propranolol into the amygdala was seen. Amygdalar β_1,2-adrenoceptors play a significant role in the acquisition and extinction of Conditioned Reflex fear in high-freezing rats, facilitating the appearance of prolonged freezing and resistance to extinction of the Reflex.
N B Saulskaya - One of the best experts on this subject based on the ideXlab platform.
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activity of the serotonin system of the prefrontal cortex in rats with high and low level of contextual fear generalization
Neuroscience and Behavioral Physiology, 2019Co-Authors: N B Saulskaya, O E MarchukAbstract:Intracerebral microdialysis studies in rats showed that acquisition of a Conditioned fear reaction (combination of Conditioned sound signal with pain reinforcement in chamber A) was accompanied by serotonin release in the medial prefrontal cortex, which did not occur in animals of the control group (same procedure but without pain stimulation). The level of serotonin release seen during acquisition of the fear reaction was high in animals demonstrating significant freezing (a measure of fear) in chamber B, not associated with pain reinforcement (high level of contextual fear generalization). Serotonin release in rats with low levels of freezing in chamber B (low contextual fear generalization) was low and did not correlate with freezing in chamber A. These data provide evidence that activation of the serotoninergic input of the medial prefrontal cortex on acquisition of the Conditioned Reflex fear reaction predicted the level of generalization of the contextual component of this reaction.
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activity of the nitrergic system of the medial prefrontal cortex in rats with high and low levels of generalization of a Conditioned Reflex fear reaction
Neuroscience and Behavioral Physiology, 2016Co-Authors: N B Saulskaya, P. V. SudorginaAbstract:In vivo intracerebral microdialysis/HPLC studies on Sprague–Dawley rats showed that acquisition of a Conditioned Reflex fear reaction (combined Conditioned sound stimulus and unavoidable electrocutaneous shock) was accompanied by an increase in the level of extracellular citrulline (a coproduct of NO synthesis) in the medial area of the prefrontal cortex. This increase was almost completely blocked by administration of the neuronal NO synthase inhibitor Nω-propyl-L-arginine (1 mM) into this area of the cortex and was not seen in animals of the control group. These increases were large in animals subsequently showing low levels of freezing (a measure of fear) in response to the differential signal not previously combined with the pain stimulus and low in rats with high levels of freezing in response to the differential signal, though they did not correlate with the level of freezing in response to the Conditioned signal. These data provide the first evidence that the formation of a Conditioned Reflex fear reaction is accompanied by activation of the nitrergic system of the medial prefrontal cortex, reflected in the extent of subsequent generalization but not expression of this Conditioned Reflex reaction.
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dopamine d1 receptors regulate the extracellular citrulline level in the nucleus accumbens during performance of a Conditioned Reflex fear reaction
Neuroscience and Behavioral Physiology, 2009Co-Authors: N B Saulskaya, N. V. FofonovaAbstract:Intracerebral microdialysis studies on Sprague–Dawley rats using HPLC showed that performance of a Conditioned Reflex fear reaction was accompanied by an increase in the extracellular citrulline (a co-product of nitric oxide synthesis) level in the nucleus accumbens. Administration of the selective D1 receptor antagonist SCH-23390 (100 μM) into the nucleus accumbens had no long-lasting effect on the extracellular citrulline level in this structure, but reduced the magnitude of the increase in the citrulline level seen on performance of the Conditioned Reflex fear reaction. These data suggest that the dopaminergic input of the nucleus accumbens acts via D1 receptors to increase NO synthase activity and nitric oxide production during performance of the Conditioned Reflex fear reaction.
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glutamatergic regulation of extracellular citrulline levels in the nucleus accumbens during an emotional Conditioned Reflex
Neuroscience and Behavioral Physiology, 2008Co-Authors: N B Saulskaya, N. V. Fofonova, S A SavelevAbstract:Intracerebral microdialysis and high-performance liquid chromatography were used to demonstrate that the acquisition and execution of an emotional Conditioned Reflex in Sprague-Dawley rats are accompanied by increases in extracellular citrulline (a co-product of nitric oxide synthesis) levels in the nucleus accumbens. Injection of the selective NMDA glutamate receptor antagonist MK-801 (100 µM) into the nucleus accumbens significantly decreased the increase in extracellular citrulline seen in this structure on acquisition of the emotional Conditioned Reflex and completely blocked the increase induced by execution of the Reflex. These data suggest that during the acquisition and execution of an emotional Conditioned revels, the glutamatergic input of the nucleus accumbens acts on NMDA receptors to stimulate nitric oxide production in this part of the brain.
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no synthase dependent increases in extracellular citrulline levels in the nucleus accumbens in an emotional Conditioned Reflex
Neuroscience and Behavioral Physiology, 2007Co-Authors: N B Saulskaya, S A Savelev, N A Soloveva, N. V. FofonovaAbstract:Intracerebral microdialysis/HPLC studies in Sprague-Dawley rats showed that the acquisition and execution of an emotional Conditioned Reflex was accompanied by an increase in the extracellular citrulline level in the nucleus accumbens; citrulline is a co-product of nitric oxide synthesis. The increase in the citrulline level evoked by execution of this Reflex decreased after injection of 7-nitroindazole (0.5 mM), a selective inhibitor of neuronal NO synthase, into the nucleus accumbens, and was completely blocked by injection of N-nitroarginine (0.5 mM), a non-selective inhibitor NO synthase. The increase in the nucleus accumbens citrulline level seen during execution of the emotional Conditioned Reflex was prevented by administration of both of these NO synthase inhibitors. These data suggest that during the acquisition and execution of the emotional Conditioned Reflex, there is an increase in nitric oxide production in the nucleus accumbens, which arises predominantly as a result of activation of neuronal NO synthase.
Nan Liu - One of the best experts on this subject based on the ideXlab platform.
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analog memristive characteristics and Conditioned Reflex study based on au zno ito devices
Electronics, 2018Co-Authors: Tiedong Cheng, Jingjing Rao, Xingui Tang, Lirong Yang, Nan LiuAbstract:As the fourth basic electronic component, the application fields of the memristive devices are diverse. The digital resistive switching with sudden resistance change is suitable for the applications of information storage, while the analog memristive devices with gradual resistance change are required in the neural system simulation. In this paper, a transparent device of ZnO films deposited by the magnetron sputtering on indium tin oxides (ITO) glass was firstly prepared and found to show typical analog memristive switching behaviors, including an I–V curve that exhibits a ‘pinched hysteresis loops’ fingerprint. The conductive mechanism of the device was discussed, and the LTspice model was built to emulate the pinched hysteresis loops of the I–V curve. Based on the LTspice model and the Pavlov training circuit, a Conditioned Reflex experiment has been successfully completed both in the computer simulation and the physical analog circuits. The prepared device also displayed synapses-like characteristics, in which resistance decreased and gradually stabilized with time under the excitation of a series of voltage pulse signals.
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Analog Memristive Characteristics and Conditioned Reflex Study Based on Au/ZnO/ITO Devices
'MDPI AG', 2018Co-Authors: Tiedong Cheng, Jingjing Rao, Xingui Tang, Lirong Yang, Nan LiuAbstract:As the fourth basic electronic component, the application fields of the memristive devices are diverse. The digital resistive switching with sudden resistance change is suitable for the applications of information storage, while the analog memristive devices with gradual resistance change are required in the neural system simulation. In this paper, a transparent device of ZnO films deposited by the magnetron sputtering on indium tin oxides (ITO) glass was firstly prepared and found to show typical analog memristive switching behaviors, including an I–V curve that exhibits a ‘pinched hysteresis loops’ fingerprint. The conductive mechanism of the device was discussed, and the LTspice model was built to emulate the pinched hysteresis loops of the I–V curve. Based on the LTspice model and the Pavlov training circuit, a Conditioned Reflex experiment has been successfully completed both in the computer simulation and the physical analog circuits. The prepared device also displayed synapses-like characteristics, in which resistance decreased and gradually stabilized with time under the excitation of a series of voltage pulse signals
Tiedong Cheng - One of the best experts on this subject based on the ideXlab platform.
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analog memristive characteristics and Conditioned Reflex study based on au zno ito devices
Electronics, 2018Co-Authors: Tiedong Cheng, Jingjing Rao, Xingui Tang, Lirong Yang, Nan LiuAbstract:As the fourth basic electronic component, the application fields of the memristive devices are diverse. The digital resistive switching with sudden resistance change is suitable for the applications of information storage, while the analog memristive devices with gradual resistance change are required in the neural system simulation. In this paper, a transparent device of ZnO films deposited by the magnetron sputtering on indium tin oxides (ITO) glass was firstly prepared and found to show typical analog memristive switching behaviors, including an I–V curve that exhibits a ‘pinched hysteresis loops’ fingerprint. The conductive mechanism of the device was discussed, and the LTspice model was built to emulate the pinched hysteresis loops of the I–V curve. Based on the LTspice model and the Pavlov training circuit, a Conditioned Reflex experiment has been successfully completed both in the computer simulation and the physical analog circuits. The prepared device also displayed synapses-like characteristics, in which resistance decreased and gradually stabilized with time under the excitation of a series of voltage pulse signals.
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Analog Memristive Characteristics and Conditioned Reflex Study Based on Au/ZnO/ITO Devices
'MDPI AG', 2018Co-Authors: Tiedong Cheng, Jingjing Rao, Xingui Tang, Lirong Yang, Nan LiuAbstract:As the fourth basic electronic component, the application fields of the memristive devices are diverse. The digital resistive switching with sudden resistance change is suitable for the applications of information storage, while the analog memristive devices with gradual resistance change are required in the neural system simulation. In this paper, a transparent device of ZnO films deposited by the magnetron sputtering on indium tin oxides (ITO) glass was firstly prepared and found to show typical analog memristive switching behaviors, including an I–V curve that exhibits a ‘pinched hysteresis loops’ fingerprint. The conductive mechanism of the device was discussed, and the LTspice model was built to emulate the pinched hysteresis loops of the I–V curve. Based on the LTspice model and the Pavlov training circuit, a Conditioned Reflex experiment has been successfully completed both in the computer simulation and the physical analog circuits. The prepared device also displayed synapses-like characteristics, in which resistance decreased and gradually stabilized with time under the excitation of a series of voltage pulse signals
V I Maiorov - One of the best experts on this subject based on the ideXlab platform.
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δ and θ modulation of fast γ activity in the ventral tegmental area of the midbrain in rats during a Conditioned avoidance Reflex
Neuroscience and Behavioral Physiology, 2016Co-Authors: A N Serkov, V I MaiorovAbstract:Execution of a Conditioned avoidance Reflex in rats was associated with the disappearance of the δ rhythm (1–4 Hz) typical of the intersignal period and synchronized between the medial prefrontal cortex and the ventral tegmental area of the midbrain (VTA), and with an increase in the frequency of the synchronized θ rhythm in the same structures and the hippocampus from 6–8 to 8–11 Hz. In terms of the “Granger causality” criterion, the δ rhythm of the prefrontal cortex and the θ rhythm of the hippocampus had predictive value in relation to these rhythms, propagating in the direction of the VTA. Failed avoidance reactions (errors, activation of the Conditioned signal in the safe sector of the chamber, acquisition of a classical unavoidable Conditioned Reflex) led to generation of the δ rhythm in response to the Conditioned signal rather than during the prestimulus period, along with disappearance of the θ synchronization between the VTA and the prefrontal cortex. The amplitude and synchronization of the fast (70–160 Hz) γ activity in the VTA with γ activity in the cortex and hippocampus and the discharge frequency of VTA neurons were modulated in relation to the phases of the δ and θ rhythms.
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interaction of the medial prefrontal cortex ventral hippocampus and basolateral amygdala during performance of a Conditioned avoidance Reflex
Neuroscience and Behavioral Physiology, 2016Co-Authors: A N Serkov, V V Serkova, V I MaiorovAbstract:The interaction between the medial prefrontal cortex, the ventral hippocampus, and the basolateral amygdala was studied during execution of a Conditioned avoidance Reflex. Slow δ activity at 1–4 Hz was recorded during the prestimulus period, with a source meeting the “Granger causality” criterion located in the prefrontal cortex, along with a θ rhythm at 6–8 Hz with a source in the hippocampus. The Conditioned avoidance Reflex was accompanied by a burst of high-frequency synchronized θ activity (8–11 Hz) and disappearance of δ activity on entry into the safe sector of the chamber. All structures showed cross-frequency phase-amplitude modulation of the amplitude of the gamma-activity (frequency from ~30 to ~120 Hz) envelope by the δ and θ rhythms. Acquisition and simplification of the Conditioned Reflex were accompanied by suppression of the power and interstructure synchronization of the θ rhythm during the Conditioned Reflex, though not during the intersignal period.
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the interaction of the medial prefrontal cortex ventral hippocampus and basolateral amygdala in the course of performance of Conditioned avoidance Reflex
Zhurnal vyssheĭ nervnoĭ deiatelnosti imeni I P Pavlova, 2015Co-Authors: A N Serkov, V V Serkova, V I MaiorovAbstract:The interaction (synchronization) of activity of the medial prefrontal cortex, hippocampus and basolateral amygdala have been studied in the course of performance of Conditioned avoidance Reflex. The pre-stimulus expectation period was characterized by low-frequency delta-activity (1-4 Hz) with the source (according to criteria of Granger causality) in the prefrontal cortex and also by synchronized theta-rhythm (6-8 Hz) in the hippocampus. The performance of Conditioned avoidance Reflex was characterized by generation of high-frequency synchronized theta-rhythm (8-11 Hz) simultaneously with delta-activity elimination. The phase of delta- (theta-) activity modulates the envelope of gamma-rhythm (~30-120 Hz) in each of the structures. The elaboration and strengthening of Conditioned Reflex leads to concurrent theta power and synchronization growth in relation to Reflex performance, but not during the prestimulus expectation period.