scholarly journals Respiratory coupling between prefrontal cortex and hippocampus of rats anesthetized with urethane in theta and non-theta states

2021 ◽  
Author(s):  
Rola Mofleh ◽  
Bernat Kocsis
Keyword(s):  
Prefrontal Cortex ◽  
Olfactory Bulb ◽  
Respiratory Rate ◽  
Higher Order ◽  
Theta Activity ◽  
Neural Mechanisms ◽  
Nasal Airflow ◽  
Freely Behaving ◽  
The Common ◽  
Respiratory Modulation

Respiratory modulation of forebrain activity, long considered hard to reliably separate from breathing artifacts, has been firmly established in recent years using a variety of advanced techniques. Respiratory related oscillation (RRO) is derived from rhythmic nasal airflow in the olfactory bulb (OB) and is conveyed to higher order brain networks, including the prefrontal cortex (PFC) and hippocampus (HC), where it may potentially contribute to communication between these structures by synchronizing their activities at the respiratory rate. RRO was shown to change with sleep-wake states, it is strongest in quiet waking, somewhat less in active waking, characterized with theta activity in the HC, and absent in sleep. The goal of this study was to test RRO synchronization between PFC and HC under urethane anesthesia where theta and non-theta states spontaneously alternate. We found that in theta states, PFC-HC coherences significantly correlated with OB-HC but not with OB-PFC, even though RRO was stronger in PFC than in HC. In non-theta states, PFC-HC synchrony correlated with coherences connecting OB to either PFC or HC. Thus, similar to freely behaving rats, PFC-HC synchrony at RRO was primarily dependent on the response of HC to the common rhythmic drive, but only in theta state. The findings help outlining the value and the limits of applications in which urethane-anesthetized rats can be used for modeling the neural mechanisms of RRO in behaving animals.

scholarly journals Delta-range coupling between prefrontal cortex and hippocampus supported by respiratory rhythmic input from the olfactory bulb in freely behaving rats

2020 ◽  
Author(s):  
Rola Mofleh ◽  
Bernat Kocsis
Keyword(s):  
Prefrontal Cortex ◽  
Olfactory Bulb ◽  
Cognitive Processes ◽  
Phase Modulation ◽  
Brain Activity ◽  
Current Source ◽  
Gamma Activity ◽  
Density Analysis ◽  
Freely Behaving ◽  
The Common

Abstract An explosion of recent findings firmly demonstrated that brain activity and cognitive function in rodents and humans are modulated synchronously with nasal respiration. Rhythmic respiratory (RR) coupling of wide-spread forebrain activity was confirmed using advanced techniques, including current source density analysis, single unit firing, and phase modulation of local gamma activity, creating solid premise for investigating how higher networks use this mechanism in their communication. Here we show essential differences in the way prefrontal cortex (PFC) and hippocampus (HC) process the RR signal from the olfactory bulb (OB) allowing dynamic PFC-HC coupling utilizing this input. We used inter-regional coherences and their correlations in rats, breathing at low rate (~ 2 Hz) at rest, outside of the short sniffing bouts. We found strong and stable OB-PFC coherence, contrasting OB-HC coherence which was low but highly variable. PFC-HC coupling, however, primarily correlated with the latter, indicating that HC access to the PFC output is dynamically regulated by the responsiveness of HC to the common rhythmic drive. This pattern was present in both theta and non-theta states of waking, whereas PFC-HC communication appeared protected from RR synchronization in sleep states. The findings help to understand the mechanism of rhythmic modulation of non-olfactory cognitive processes by the on-going regular respiration, reported in rodents as well as humans. These mechanisms may also be important to understand how OB-pathology may lead to neurological consequences, similar to known olfactory disturbances in COVID-19.

scholarly journals Delta-range coupling between prefrontal cortex and hippocampus supported by respiratory rhythmic input from the olfactory bulb in freely behaving rats

2020 ◽  
Author(s):  
Rola Mofleh ◽  
Bernat Kocsis
Keyword(s):  
Prefrontal Cortex ◽  
Olfactory Bulb ◽  
Cognitive Processes ◽  
Phase Modulation ◽  
Brain Activity ◽  
Current Source ◽  
Gamma Activity ◽  
Density Analysis ◽  
Freely Behaving ◽  
The Common

Abstract An explosion of recent findings firmly demonstrated that brain activity and cognitive function in rodents and humans are modulated synchronously with nasal respiration. Rhythmic respiratory (RR) coupling of wide-spread forebrain activity was confirmed using advanced techniques, including current source density analysis, single unit firing, and phase modulation of local gamma activity, creating solid premise for investigating how higher networks use this mechanism in their communication. Here we show essential differences in the way prefrontal cortex (PFC) and hippocampus (HC) process the RR signal from the olfactory bulb (OB) allowing dynamic PFC-HC coupling utilizing this input. We used inter-regional coherences and their correlations in rats, breathing at low rate (~2 Hz) at rest, outside of the short sniffing bouts. We found strong and stable OB-PFC coherence, contrasting OB-HC coherence which was low but highly variable. PFC-HC coupling, however, primarily correlated with the latter, indicating that HC access to the PFC output is dynamically regulated by the responsiveness of HC to the common rhythmic drive. This pattern was present in both theta and non-theta states of waking, whereas PFC-HC communication appeared protected from RR synchronization in sleep states. The findings help to understand the mechanism of rhythmic modulation of non-olfactory cognitive processes by the on-going regular respiration, reported in rodents as well as humans. These mechanisms may also be important to understand how OB-pathology may lead to neurological consequences, similar to known olfactory disturbances in COVID-19.

scholarly journals Delta-range coupling between prefrontal cortex and hippocampus supported by respiratory rhythmic input from the olfactory bulb

2020 ◽  
Author(s):  
Rola Mofleh ◽  
Bernat Kocsis
Keyword(s):  
Prefrontal Cortex ◽  
Olfactory Bulb ◽  
Cognitive Processes ◽  
Phase Modulation ◽  
Theta Rhythm ◽  
Current Source ◽  
Respiratory Rhythm ◽  
Gamma Activity ◽  
The Common ◽  
Hippocampal Theta

AbstractRespiratory rhythm (RR) during sniffing is known to couple with hippocampal theta rhythm. However, outside of the short sniffing bouts, a more stable ~2Hz RR was recently shown to rhythmically modulate non-olfactory cognitive processes, as well. The underlying RR coupling with wide-spread forebrain activity was confirmed using advanced techniques, including current source density and phase modulation of local gamma activity, creating solid premise for investigating how higher networks use this mechanism in their communication. Here we show essential differences in the way prefrontal cortex (PFC) and hippocampus (HC) processes the RR signal from the olfactory bulb (OB) allowing dynamic PFC-HC coupling utilizing this input. We found stable OB-PFC coherence in waking contrasting low but highly variable OB-HC coherence. PFC-HC coupling however primarily correlated with the latter, indicating that HC access to the PFC output readily segmented and shaped by RR in the delta range is dynamically regulated by the responsiveness of HC to the common rhythmic drive.

scholarly journals Delta-range coupling between prefrontal cortex and hippocampus supported by respiratory rhythmic input from the olfactory bulb in freely behaving rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rola Mofleh ◽  
Bernat Kocsis
Keyword(s):  
Prefrontal Cortex ◽  
Olfactory Bulb ◽  
Cognitive Processes ◽  
Theta Rhythm ◽  
Respiratory Rhythm ◽  
Wide Spread ◽  
Nasal Breathing ◽  
Freely Behaving ◽  
Hippocampal Theta ◽  
Low Rate

AbstractRespiratory rhythm (RR) during sniffing is known to couple with hippocampal theta rhythm. However, outside of the short sniffing bouts, a more stable ~ 2 Hz RR was recently shown to rhythmically modulate non-olfactory cognitive processes, as well. The underlying RR coupling with wide-spread forebrain activity was confirmed using advanced techniques, creating solid premise for investigating how higher networks use this mechanism in their communication. Here we show essential differences in the way prefrontal cortex (PFC) and hippocampus (HC) process the RR signal from the olfactory bulb (OB) that may support dynamic, flexible PFC-HC coupling utilizing this input. We used inter-regional coherences and their correlations in rats, breathing at low rate (~ 2 Hz), outside of the short sniffing bouts. We found strong and stable OB-PFC coherence in wake states, contrasting OB-HC coherence which was low but highly variable. Importantly, this variability was essential for establishing PFC-HC synchrony at RR, whereas variations of RRO in OB and PFC had no significant effect. The findings help to understand the mechanism of rhythmic modulation of non-olfactory cognitive processes by the on-going regular respiration, reported in rodents as well as humans. These mechanisms may be impaired when nasal breathing is limited or in OB-pathology, including malfunctions of the olfactory epithelium due to infections, such as in Covid-19.

scholarly journals N-soliton solutions and the Hirota conditions in (1 + 1)-dimensions

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wen-Xiu Ma
Keyword(s):  
Common Factors ◽  
Soliton Solutions ◽  
Higher Order ◽  
Kdv Equations ◽  
The Common ◽  
Bilinear Formulation ◽  
Generalized Kdv Equations ◽  
Hirota Bilinear

Abstract We analyze N-soliton solutions and explore the Hirota N-soliton conditions for scalar (1 + 1)-dimensional equations, within the Hirota bilinear formulation. An algorithm to verify the Hirota conditions is proposed by factoring out common factors out of the Hirota function in N wave vectors and comparing degrees of the involved polynomials containing the common factors. Applications to a class of generalized KdV equations and a class of generalized higher-order KdV equations are made, together with all proofs of the existence of N-soliton solutions to all equations in two classes.

scholarly journals Retrieval practice facilitates memory updating by enhancing and differentiating medial prefrontal cortex representations

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Zhifang Ye ◽  
Liang Shi ◽  
Anqi Li ◽  
Chuansheng Chen ◽  
Gui Xue
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Pattern Analysis ◽  
Retrieval Practice ◽  
Neural Mechanisms ◽  
Neural Activation ◽  
Final Test ◽  
Memory Updating ◽  
Practice Condition ◽  
Memory Integration

Updating old memories with new, more current information is critical for human survival, yet the neural mechanisms for memory updating in general and the effect of retrieval practice in particular are poorly understood. Using a three-day A-B/A-C memory updating paradigm, we found that compared to restudy, retrieval practice could strengthen new A-C memories and reduce old A-B memory intrusion, but did not suppress A-B memories. Neural activation pattern analysis revealed that compared to restudy, retrieval practice led to stronger target representation in the medial prefrontal cortex (MPFC) during the final test. Critically, it was only under the retrieval practice condition that the MPFC showed strong and comparable competitor evidence for both correct and incorrect trials during final test, and that the MPFC target representation during updating was predictive of subsequent memory. These results suggest that retrieval practice is able to facilitate memory updating by strongly engaging MPFC mechanisms in memory integration, differentiation and consolidation.

Modes of Ventilation

2019 ◽  
Author(s):  
Michael J Harrison
Keyword(s):  
Respiratory Rate ◽  
Pulmonary Ventilation ◽  
Lung Ventilation ◽  
Intrathoracic Pressure ◽  
Jet Ventilation ◽  
Hemodynamic Stability ◽  
Advantages And Disadvantages ◽  
Basic Parameters ◽  
Anesthesia Machines ◽  
The Common

Lung ventilation is required to maintain oxygenation and eliminate carbon dioxide. The basic parameters of ventilation—tidal volume, respiratory rate, airway resistance, and lung and thoracic compliance—all combine to affect the airway pressure. These parameters, in turn, can affect cardiac output and hemodynamic stability through their effect on intrathoracic pressure and on venous return to the heart. Since the 1950s, many machines have been designed to allow the physician to optimize ventilation. These designs have revolved around three physical variables: volume, pressure, and time. Volume is required to overcome the anatomic respiratory dead space and allows gas exchange in the alveoli. Pressure is required to inflate the elastic system comprising the lungs and thorax, but must also be limited to prevent tissue damage. Time not only determines the respiratory rate but also the rate of flow of gas in and out of the lungs. Many permutations of these basic parameters in anesthesia machines are available today. Knowledge of the common forms of ventilation and their advantages and disadvantages will guide the anesthesiologist in choosing from among these various complex systems. This review contains 5 figures, 3 tables, and 27 references. Key words: CPAP, HFOV, IMV, IPPV, jet ventilation, PEEP, pressure cycled, pulmonary ventilation, SIMV, spontaneous, volume cycled

Respiratory modulation of olfactory bulb unit activity in the cat

1988 ◽  
Vol 7 ◽  
pp. S38
Author(s):  
Yoichi Ogawa ◽  
Fumiyo Shimomura ◽  
Fumiaki Motokizawa
Keyword(s):  
Olfactory Bulb ◽  
Unit Activity ◽  
Respiratory Modulation
Sign in / Sign up

Export Citation Format

Share Document