scholarly journals Proprioceptive feedback modulates coordinating information in a system of segmentally distributed microcircuits

2014 ◽  
Vol 112 (11) ◽  
pp. 2799-2809 ◽  
Author(s):  
Brian Mulloney ◽  
Carmen Smarandache-Wellmann ◽  
Cynthia Weller ◽  
Wendy M. Hall ◽  
Ralph A. DiCaprio
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neural Circuits ◽  
Rhythmic Activity ◽  
Pacifastacus Leniusculus ◽  
Power Stroke ◽  
Cycle Period ◽  
Return Stroke ◽  
Stretch Receptors ◽  
Phase Differences

The system of modular neural circuits that controls crustacean swimmerets drives a metachronal sequence of power-stroke (PS, retraction) and return-stroke (RS, protraction) movements that propels the animal forward efficiently. These neural modules are synchronized by an intersegmental coordinating circuit that imposes characteristic phase differences between these modules. Using a semi-intact preparation that left one swimmeret attached to an otherwise isolated central nervous system (CNS) of the crayfish, Pacifastacus leniusculus, we investigated how the rhythmic activity of this system responded to imposed movements. We recorded extracellularly from the PS and RS nerves that innervated the attached limb and from coordinating axons that encode efference copies of the periodic bursts in PS and RS axons. Simultaneously, we recorded from homologous nerves in more anterior and posterior segments. Maintained retractions did not affect cycle period but promptly weakened PS bursts, strengthened RS bursts, and caused corresponding changes in the strength and timing of efference copies in the module's coordinating axons. Changes in these efference copies then caused changes in the phase and duration, but not the strength, of PS bursts in modules controlling neighboring swimmerets. These changes were promptly reversed when the limb was released. Each swimmeret is innervated by two nonspiking stretch receptors (NSSRs) that depolarize when the limb is retracted. Voltage clamp of an NSSR changed the durations and strengths of bursts in PS and RS axons innervating the same limb and caused corresponding changes in the efference copies of this motor output.

scholarly journals Odorant Receptors Signaling Instructs the Development and Plasticity of the Glomerular Map

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Pablo Valle-Leija
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Olfactory System ◽  
Neural Circuits ◽  
Odorant Receptors ◽  
Great Opportunity ◽  
Essential Information ◽  
Olfactory Information ◽  
The Central Nervous System ◽  
And Function

The olfactory system provides a great opportunity to explore the mechanisms that underlie the formation and function of neural circuits because of the simplicity of its structure. Olfactory sensory neurons (OSNs) located in the peripheral olfactory epithelium (OE) take part in the initial formation and function of glomeruli in the olfactory bulb (OB) inside the central nervous system. Glomeruli are key in the process of transduction of olfactory information, as they constitute a map in the OB that sorts the different types of odorant inputs. This odorant categorization allows proper olfactory perception, and it is achieved through the anatomical organization and function of the different glomerular circuits. Once formed, glomeruli keep the capacity to undergo diverse plasticity processes, which is unique among the different neural circuits of the central nervous system. In this context, through the expression and function of the odorant receptors (ORs), OSNs perform two of the most important roles in the olfactory system: transducing odorant information to the nervous system and initiating the development of the glomerular map to organize olfactory information. This review addresses essential information that has emerged in recent years about the molecular basis of these processes.

Experiments on the central pattern generator for swimming in amphibian embryos

1982 ◽  
Vol 296 (1081) ◽  
pp. 229-243 ◽  
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Pattern Generator ◽  
Pattern Generation ◽  
Motor Output ◽  
Cycle Period ◽  
Sensory Stimuli ◽  
Swimming Pattern ◽  
Left And Right

The central nervous system of paralysed Xenopus laevis embryos can generate a motor output pattern suitable for swimming locomotion. By recording motor root activity in paralysed embryos with transected nervous systems we have shown that: (a) the spinal cord is capable of swimming pattern generation; (b) swimming pattern generator capability in the hindbrain and spinal cord is distributed; (c) caudal hindbrain is necessary for sustained swimming output after discrete stimulation. By recording similarly from embryos whose central nervous system was divided longitudinally into left and right sides, we have shown that: (a) each side can generate rhythmic motor output with cycle periods like those in swimming; (b) during this activity cycle period increases within an episode, and there is the usual rostrocaudal delay found in swimming; (c) this activity is influenced by sensory stimuli in the same way as swimming activity; ( d) normal phase coupling of the left and right sides can be established by the ventral commissure in the spinal cord. We conclude that interactions between the antagonistic (left and right) motor systems are not necessary for swimming rhythm generation and present a model for swimming pattern generation where autonomous rhythm generators on each side of the nervous system drive the motoneurons. Alternation is achieved by reciprocal inhibition, and activity is initiated and maintained by tonic excitation from the hindbrain.

scholarly journals Regenerative Potential of Carbon Monoxide in Adult Neural Circuits of the Central Nervous System

2020 ◽  
Vol 21 (7) ◽  
pp. 2273
Author(s):  
Eunyoung Jung ◽  
Seong-Ho Koh ◽  
Myeongjong Yoo ◽  
Yoon Kyung Choi
Keyword(s):  
Central Nervous System ◽  
Carbon Monoxide ◽  
Nervous System ◽  
Neurotrophic Factors ◽  
Neural Circuits ◽  
Cns Injury ◽  
Cns Regeneration ◽  
The Central Nervous System ◽  
Endogenous Neural Stem Cells

Regeneration of adult neural circuits after an injury is limited in the central nervous system (CNS). Heme oxygenase (HO) is an enzyme that produces HO metabolites, such as carbon monoxide (CO), biliverdin and iron by heme degradation. CO may act as a biological signal transduction effector in CNS regeneration by stimulating neuronal intrinsic and extrinsic mechanisms as well as mitochondrial biogenesis. CO may give directions by which the injured neurovascular system switches into regeneration mode by stimulating endogenous neural stem cells and endothelial cells to produce neurons and vessels capable of replacing injured neurons and vessels in the CNS. The present review discusses the regenerative potential of CO in acute and chronic neuroinflammatory diseases of the CNS, such as stroke, traumatic brain injury, multiple sclerosis and Alzheimer’s disease and the role of signaling pathways and neurotrophic factors. CO-mediated facilitation of cellular communications may boost regeneration, consequently forming functional adult neural circuits in CNS injury.

Aspects of the Organization of Central Nervous Pathways in Aplysia Depilans

1962 ◽  
Vol 39 (1) ◽  
pp. 45-69
Author(s):  
G. M. HUGHES ◽  
L. TAUC
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ganglion Cells ◽  
Rhythmic Activity ◽  
Large Size ◽  
The Central Nervous System ◽  
The Individual ◽  
Two Sides ◽  
Pleural Ganglion

1. The organization of the central nervous system of Aplysia depilans has been investigated in whole animal and isolated ganglion preparations using mechanical and electrical stimulation. 2. Intracellular micro-electrodes have been used to record activity in nerve cells of the abdominal ganglia in situ. Some cells are spontaneously active and quite unaffected by mechanical stimulation, whereas others show varying degrees of responsiveness. Those which are unaffected may exhibit regular rhythmic activity or intermittent bursts which are intrinsic to the cells themselves but in other cases are due to synaptic input from other central neurones. 3. In isolated central nervous system preparations a special study of the pleural ganglion has revealed many types of cell with electrical activity similar to that shown in isolated abdominal ganglion preparations. A notable feature of the pleural ganglion cells was the large size of the excitatory post-synaptic potentials recorded in response to stimulation of pre-synaptic fibres. 4. Different types of branching of cells of the pleural ganglia were investigated. By observing the somatic potential it was possible to decide in which nerve a particular cell sent collateral branches and which nerves contained fibres affecting the cell synaptically. By this means it was clear that a large number of pathways connect the cerebral and pleural ganglia on each side. 5. A large number of direct pathways were found of nerve fibres passing through ganglia without any synapse. 6. Synaptic pathways varied in the number and intrinsic properties of the individual synapses along their route. Synapses between fibres in the nerves innervating the foot and parapodial lobes of the two sides were not as common as has been described for Ariolimax. 7. In general the results have shown a great variety in the extent to which afferent stimulation may affect the whole or part of the central nervous system. They have also revealed the great multiplicity in the pathways whereby this is achieved.

Optogenetics: The Key to Deciphering and Curing Neurological Diseases

2020 ◽  
Vol 35 (4) ◽  
pp. 224-235
Author(s):  
Fuzhou Wang
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Essential Role ◽  
Neural Circuits ◽  
Neurological Diseases ◽  
Nervous System Diseases ◽  
Central Nervous System Diseases ◽  
Light Control ◽  
Excitable Cells ◽  
Neuronal Membranes

Optogenetics is an emerging branch of biology that combines genetics and optics to achieve precise light control of specific cells in organisms. It is a method of studying excitable cells that uses proteins that are embedded in the cell membrane and are activated by light (i.e. “opto”). Such proteins (opsins) are found in most animals in the retina of the eyes, as well as in some plants, such as green algae. In order to integrate photoactivated proteins into neuronal membranes, it is necessary to introduce rhodopsin genes obtained from other organisms into neurons, hence the “genetics”. Optogenetics is widely used in the field of modern neurobiology, and plays an essential role in the study of the mechanism of neural circuits, behaviors, central nervous system diseases, and mental disorders. Based on the development of optogenetics technology, this paper introduces its optimization and localization expression, which not only provides references for the research and development of optogenetics, but also provides the possibility for in-depth research and treatment of neurological diseases.

scholarly journals The gateway reflex: breaking through the blood barriers

2021 ◽  
Author(s):  
Kaoru Murakami ◽  
Yuki Tanaka ◽  
Masaaki Murakami
Keyword(s):  
Central Nervous System ◽  
T Cells ◽  
Endothelial Cells ◽  
Nervous System ◽  
Neural Circuits ◽  
Inflammatory Diseases ◽  
Special Focus ◽  
Tissue Specific ◽  
The Central Nervous System ◽  
Pass Through

Abstract We have been studying inflammatory diseases, with a special focus on IL-6, and discovered two concepts related to inflammation development. One is the gateway reflex, which is induced by the activation of specific neural circuits followed by establishing gateways for autoreactive CD4+ T cells to pass through blood barriers toward the central nervous system (CNS) and retina during tissue-specific inflammatory diseases. We found that the formation of these gateways is dependent on the IL-6 amplifier, which is machinery for enhanced NF-κB activation in endothelial cells at specific sites. We have found five gateway reflexes in total. Here, we introduce the gateway reflex and the IL-6 amplifier.

scholarly journals Stereotyped terminal axon branching of leg motor neurons mediated by IgSF proteins DIP-α and Dpr10

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Lalanti Venkatasubramanian ◽  
Zhenhao Guo ◽  
Shuwa Xu ◽  
Liming Tan ◽  
Qi Xiao ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Neurons ◽  
Neural Circuits ◽  
Neuromuscular System ◽  
Morphological Complexity ◽  
Terminal Axon ◽  
Branching Patterns ◽  
Ig Superfamily ◽  
The Central Nervous System

For animals to perform coordinated movements requires the precise organization of neural circuits controlling motor function. Motor neurons (MNs), key components of these circuits, project their axons from the central nervous system and form precise terminal branching patterns at specific muscles. Focusing on the Drosophila leg neuromuscular system, we show that the stereotyped terminal branching of a subset of MNs is mediated by interacting transmembrane Ig superfamily proteins DIP-α and Dpr10, present in MNs and target muscles, respectively. The DIP-α/Dpr10 interaction is needed only after MN axons reach the vicinity of their muscle targets. Live imaging suggests that precise terminal branching patterns are gradually established by DIP-α/Dpr10-dependent interactions between fine axon filopodia and developing muscles. Further, different leg MNs depend on the DIP-α and Dpr10 interaction to varying degrees that correlate with the morphological complexity of the MNs and their muscle targets.

Acute cardiovascular response to isocapnic hypoxia. I. A mathematical model

2000 ◽  
Vol 279 (1) ◽  
pp. H149-H165 ◽  
Author(s):  
Mauro Ursino ◽  
Elisa Magosso
Keyword(s):  
Mathematical Model ◽  
Central Nervous System ◽  
Heart Rate ◽  
Blood Flow ◽  
Nervous System ◽  
Cardiac Output ◽  
Cardiovascular Response ◽  
Stretch Receptors ◽  
The Central Nervous System ◽  
Lung Stretch

A mathematical model of the acute cardiovascular response to isocapnic hypoxia is presented. It includes a pulsating heart, the systemic and pulmonary circulation, a separate description of the vascular bed in organs with the higher metabolic need, and the local effect of O2 on these organs. Moreover, the model also includes the action of several reflex regulatory mechanisms: the peripheral chemoreceptors, the lung stretch receptors, the arterial baroreceptors, and the hypoxic response of the central nervous system. All parameters in the model are given in accordance with the physiological literature. The simulated overall response to a deep hypoxia (28 mmHg) agrees with the experimental data quite well, showing a biphasic pattern. The early phase (8–10 s), caused by activation of peripheral chemoreceptors, exhibits a moderate increase in mean systemic arterial pressure, a decrease in heart rate, a quite constant cardiac output, and a redistribution of blood flow to the organs with higher metabolic need at the expense of other organs. The later phase (20 s) is characterized by the activation of lung stretch receptors and by the central nervous system hypoxic response. During this phase, cardiac output and heart rate increase together, and blood flow is restored to normal levels also in organs with lower metabolic need. The model may be used to gain a deeper understanding of the role of each mechanism in the overall cardiovascular response to hypoxia.

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