scholarly journals Monosynaptic projections to excitatory and inhibitory preBötzinger Complex neurons

2019 ◽  
Author(s):  
Cindy F. Yang ◽  
Euiseok J. Kim ◽  
Edward M. Callaway ◽  
Jack L. Feldman

AbstractThe key driver of breathing rhythm is the preBötzinger Complex (preBötC) whose activity is modulated by various categorical inputs, e.g., volitional, physiological, emotional. While the preBötC is highly interconnected with other regions of the breathing central pattern generator (bCPG) in the brainstem, there is no data about the direct projections to either excitatory and inhibitory preBötC subpopulations from other elements of the bCPG or from suprapontine regions. Using modified rabies tracing, we identified neurons throughout the brain that send monosynaptic projections to identified excitatory and inhibitory preBötC neurons. Within the brainstem, neurons from sites in the bCPG, including the contralateral preBötC, Bötzinger Complex (BötC), the nucleus of the solitary tract (NTS), parafacial region (pFL/pFV or RTN/pFRG), and parabrachial nuclei, send direct projections to both excitatory and inhibitory preBötC neurons. Suprapontine inputs to the excitatory and inhibitory preBötC neurons include the superior colliculus, red nucleus, amygdala, hypothalamus, and cortex; these projections represent potential direct pathways for volitional, emotional, and physiological control of breathing.

2020 ◽  
Author(s):  
Valentin Slepukhin ◽  
Sufyan Ashhad ◽  
Jack L. Feldman ◽  
Alex J. Levine

The preBötzinger Complex, the mammalian inspiratory rhythm generator, encodes inspiratory time as motor pattern. Spike synchronization throughout this sparsely connected network generates inspiratory bursts albeit with variable latencies after preinspiratory activity onset in each breathing cycle. Using preBötC rhythmogenic microcircuit minimal models, we examined the variability in probability and latency to burst, mimicking experiments. Among various physiologically plausible graphs of 1000 point neurons with experimentally determined neuronal and synaptic parameters, directed Erdős-Rényi graphs best captured the experimentally observed dynamics. Mechanistically, preBötC (de)synchronization and oscillatory dynamics are regulated by the efferent connectivity of spiking neurons that gates the amplification of modest preinspiratory activity through input convergence. Furthermore, to replicate experiments, a lognormal distribution of synaptic weights was necessary to augment the efficacy of convergent coincident inputs. These mechanisms enable exceptionally robust yet flexible preBötC attractor dynamics that, we postulate, represent universal temporal-processing and decision-making computational motifs throughout the brain.


2001 ◽  
Vol 4 (9) ◽  
pp. 927-930 ◽  
Author(s):  
Paul A. Gray ◽  
Wiktor A. Janczewski ◽  
Nicholas Mellen ◽  
Donald R. McCrimmon ◽  
Jack L. Feldman

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Yong Zhang ◽  
Vivian Biancardi ◽  
Ana Miranda Tapia ◽  
Toka Abu Jaib ◽  
Alexander Gourine ◽  
...  

2021 ◽  
Vol 74 (3-4) ◽  
pp. 126-128
Author(s):  
Zsolt Kulcsár ◽  
Paolo Machi ◽  
Maria Isabel Vargas ◽  
Karl Schaller ◽  
Karl Olof Lovblad

The subtypes of brain arteriovenous malformations, with direct, single-hole fistulas without co-existing nidus are not described as existing entities inside the brain parenchyma but on the pial surface. True parenchymal arteriovenous malformations present with nidal structure, even if they are small, whereas surface lesions may present a direct fistulous configuration. In this case of midbrain haemorrhage a direct arteriovenous fistula was detected at the level of the red nucleus between a paramedian midbrain perforator artery and a paramedian parenchymal vein, with pseudo-aneurysm formation at the fistulous connection, without signs of adjacent nidus structure. The hypothesis whether a pre-existing arteriovenous fistula ruptured or a spontaneous haemorrhage has caused the fistulous connection is discussed.


2001 ◽  
Vol 85 (6) ◽  
pp. 2461-2467 ◽  
Author(s):  
Xuesi M. Shao ◽  
Jack L. Feldman

Cholinergic neurotransmission plays a role in regulation of respiratory pattern. Nicotine from cigarette smoke affects respiration and is a risk factor for sudden infant death syndrome (SIDS) and sleep-disordered breathing. The cellular and synaptic mechanisms underlying this regulation are not understood. Using a medullary slice preparation from neonatal rat that contains the preBötzinger Complex (preBötC), the hypothesized site for respiratory rhythm generation, and generates respiratory-related rhythm in vitro, we examined the effects of nicotine on excitatory neurotransmission affecting inspiratory neurons in preBötC and on the respiratory-related motor activity from hypoglossal nerve (XIIn). Microinjection of nicotine into preBötC increased respiratory frequency and decreased the amplitude of inspiratory bursts, whereas when injected into XII nucleus induced a tonic activity and an increase in amplitude but not in frequency of inspiratory bursts from XIIn. Bath application of nicotine (0.2–0.5 μM, approximately the arterial blood nicotine concentration immediately after smoking a cigarette) increased respiratory frequency up to 280% of control in a concentration-dependent manner. Nicotine decreased the amplitude to 82% and increased the duration to 124% of XIIn inspiratory bursts. In voltage-clamped preBötC inspiratory neurons (including neurons with pacemaker properties), nicotine induced a tonic inward current of −19.4 ± 13.4 pA associated with an increase in baseline noise. Spontaneous excitatory postsynaptic currents (sEPSCs) present during the expiratory period increased in frequency to 176% and in amplitude to 117% of control values; the phasic inspiratory drive inward currents decreased in amplitude to 66% and in duration to 89% of control values. The effects of nicotine were blocked by mecamylamine (Meca). The inspiratory drive current and sEPSCs were completely eliminated by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) in the presence or absence of nicotine. In the presence of tetrodotoxin (TTX), low concentrations of nicotine did not induce any tonic current or any increase in baseline noise, nor affect the input resistance in inspiratory neurons. In this study, we demonstrated that nicotine increased respiratory frequency and regulated respiratory pattern by modulating the excitatory neurotransmission in preBötC. Activation of nicotinic acetylcholine receptors (nAChRs) enhanced the tonic excitatory synaptic input to inspiratory neurons including pacemaker neurons and at the same time, inhibited the phasic excitatory coupling between these neurons. These mechanisms may account for the cholinergic regulation of respiratory frequency and pattern.


2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
Caroline C. Szujewski ◽  
Chrishon Campbell ◽  
Alfredo J. Garcia

2021 ◽  
Vol 35 (S1) ◽  
Author(s):  
Ana Miranda Tapia ◽  
Vivian Biancardi ◽  
Robert Reklow ◽  
Wei Zhang ◽  
Vladimir Rancic ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document