Vasopressin increases the central nervous system suppressive control over gill reflex behaviours and associated neural activity in Aplysia

1980 ◽  
Vol 58 (5) ◽  
pp. 583-587 ◽  
Author(s):  
Ken Lukowiak ◽  
J. A. Thornhill ◽  
K. E. Cooper ◽  
W. L. Veale
Keyword(s):  
Central Nervous System ◽  
Neural Activity ◽  
Action Potentials ◽  
Membrane Properties ◽  
Synaptic Efficacy ◽  
Behavioural Responses ◽  
Withdrawal Reflex ◽  
Neurohypophyseal Hormone ◽  
The Central Nervous System ◽  
Passive Membrane Properties

Exposure of the abdominal ganglion of Aplysia to arginine vasopressin (10−12 M) reduces the amplitude of the gill withdrawal reflex, accelerates its rate of habituation, and causes a concomitant decrease in the number of action potentials evoked in gill motor neuron L7. The effects of vasopressin on both the reflex and the concomitant neural activity evoked in L7 were completely reversible. Vasopressin did not affect the passive membrane properties of L7. The results indicate that a vertebrate neurohypophyseal hormone can affect behavioural responses as well as modify the synaptic efficacy of the reflex pathway.

scholarly journals Reduced motoneuron excitability in a rat model of sepsis

2013 ◽  
Vol 109 (7) ◽  
pp. 1775-1781 ◽  
Author(s):  
Paul Nardelli ◽  
Jaffar Khan ◽  
Randall Powers ◽  
Tim C. Cope ◽  
Mark M. Rich
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Intensive Care ◽  
Motor Unit ◽  
Action Potentials ◽  
Cecal Ligation ◽  
Membrane Properties ◽  
Whole Body ◽  
Repetitive Firing ◽  
The Central Nervous System

Many critically ill patients in intensive care units suffer from an infection-induced whole body inflammatory state known as sepsis, which causes severe weakness in patients who survive. The mechanisms by which sepsis triggers intensive care unit-acquired weakness (ICUAW) remain unclear. Currently, research into ICUAW is focused on dysfunction of the peripheral nervous system. During electromyographic studies of patients with ICUAW, we noticed that recruitment was limited to few motor units, which fired at low rates. The reduction in motor unit rate modulation suggested that functional impairment within the central nervous system contributes to ICUAW. To understand better the mechanism underlying reduced firing motor unit firing rates, we moved to the rat cecal ligation and puncture model of sepsis. In isoflurane-anesthetized rats, we studied the response of spinal motoneurons to injected current to determine their capacity for initiating and firing action potentials repetitively. Properties of single action potentials and passive membrane properties of motoneurons from septic rats were normal, suggesting excitability was normal. However, motoneurons exhibited striking dysfunction during repetitive firing. The sustained firing that underlies normal motor unit activity and smooth force generation was slower, more erratic, and often intermittent in septic rats. Our data are the first to suggest that reduced excitability of neurons within the central nervous system may contribute to ICUAW.

scholarly journals Assessment of acute and sub-chronic neurotoxicity of Morus alba L. fruits in rodents

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Arpita Paul ◽  
Anshul Shakya ◽  
Md Kamaruz Zaman
Keyword(s):  
Central Nervous System ◽  
Morus Alba ◽  
Neuroprotective Activity ◽  
Repeated Treatment ◽  
Fruit Extract ◽  
Hot Plate ◽  
Organ Weights ◽  
Behavioural Responses ◽  
Limit Test ◽  
The Central Nervous System

Abstract Background Morus alba L. fruits are consumed since long for their nutritional and medicinal values. Although there were studies on the neuroprotective activity of the fruit extract, safety profile of the fruit extract is not yet explored as per the recommended standard guidelines over the central nervous system (CNS). The present work was aimed to assess the neurotoxicity profile of chemically characterized extract of M. alba L. fruits (MA) using validated OECD guidelines, i.e., 425 and 424 in rodents. Results Neurobehavioural parameters were examined for motor, sensory and behavioural responses using actophotometer, hot plate and light and dark box test, respectively as per OECD 424. Interestingly, no sign of mortality and/or adversity on mice treated per-orally with MA (2000 mg/kg) was observed during the limit test as per OECD 425. Further, rats treated with MA (1000, 300 and 100 mg/kg, p.o.) for 28 days, showed insignificant (p < 0.05) changes in body weight, food consumption, neurobehavioural responses, organ weights and biochemical, haematological and histopathological features when compared with vehicle-treated animals. Conclusion The outcome of findings suggests that MA is safe in acute oral as well as sub-chronic (28 days) administration in mice and rats respectively. MA (1000 mg/kg) did not pose any toxic sign and symptoms on neurobehavioural responses in rats even after 28 days repeated treatment in compliance with OECD 424.

Synaptic transmission in the chronically decentralized middle cervical and stellate ganglia of the dog

1983 ◽  
Vol 61 (10) ◽  
pp. 1149-1155 ◽  
Author(s):  
J. A. Armour
Keyword(s):  
Central Nervous System ◽  
Action Potentials ◽  
Autonomic Nerves ◽  
Autonomic Ganglia ◽  
Afferent Nerves ◽  
Stellate Ganglia ◽  
Compound Action Potentials ◽  
The Central Nervous System ◽  
Compound Action ◽  
Stimulation Of

Afferent stimulation of one thoracic cardiopulmonary nerve generated compound action potentials in the efferent axons of other ipsilateral cardiopulmonary nerves in dogs, 14 days after their thoracic autonomic ganglia had been decentralized. The compound action potentials were influenced by the frequency of activation and (in 5 of 12 dogs) by pharmacological autonomic blocking agents (hexamethonium, atropine, phentolamine, and propranolol). Moreover, they were abolished transiently when chymotrypsin was injected locally into the ganglia, and extendedly when manganese was injected. Thus, synapses that can be activated by stimulation of afferent nerves exist in chronically decentralized thoracic autonomic nerves and ganglia. It is proposed that regulation of the heart and lungs occurs in part via thoracic autonomic neural elements independent of the central nervous system.

The development of central nervous system control of the gill withdrawal reflex evoked by siphon stimulation in Aplysia

1979 ◽  
Vol 57 (9) ◽  
pp. 987-997 ◽  
Author(s):  
Ken Lukowiak
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Abdominal Ganglion ◽  
System Control ◽  
Reflex Amplitude ◽  
Withdrawal Reflex ◽  
Reflex Latency ◽  
Neural Processes ◽  
The Central Nervous System ◽  
Cns Control

In older Aplysia, the central nervous system (CNS) (abdominal ganglion) exerts suppressive and facilitatory control over the peripheral nervous system (PNS) which initially mediates the gill withdrawal reflex and its subsequent habituation evoked by tactile stimulation of the siphon. In young animals, both the suppressive and facilitatory CNS control were found to be absent. In older animals, removal of branchial nerve (Br) input to the gill resulted in a significantly reduced reflex latency and, with ctenidial (Ct) and siphon (Sn) nerves intact, a significantly increased reflex amplitude and an inability of the reflex to habituate with repeated siphon stimulation. In young animals, removal of Br had no effect on reflex latency and with Ct and Sn intact, the reflex amplitude latency was not increased and the reflex habituated. Older animals can easily discriminate between different intensity stimuli applied to the siphon as evidenced by differences in reflex amplitude, rates of habituation, and evoked neural activity. On the other hand, young animals cannot discriminate well between different stimulus intensities. The lack of CNS control in young animals was found to be due to incompletely developed neural processes within the abdominal ganglion and not the PNS. The lack of CNS control in young Aplysia results in gill reflex behaviours being less adaptive in light of changing stimulus conditions, but may be of positive survival value in that the young will not habituate as easily. The fact that CNS control is present in older animals strengthens the idea that in any analysis of the underlying neural mechanisms of habituation the entire integrated CNS–PNS must be taken into account.

Dopamine modulation of gill reflex behavior in Aplysia

1979 ◽  
Vol 57 (3) ◽  
pp. 329-332 ◽  
Author(s):  
Peter Ruben ◽  
Ken Lukowiak
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Motor Neuron ◽  
Peripheral Nervous System ◽  
Motor Neurons ◽  
Withdrawal Reflex ◽  
Dopaminergic Pathway ◽  
The Central Nervous System ◽  
Dopamine Modulation

We have studied the effects of dopamine on the gill withdrawal reflex evoked by tactile siphon stimulation in the margine mollusc Aplysia. Physiological concentrations of dopamine (diluted in seawater) were perfused through the gill during siphon stimulation series. The amplitude of the reflex was potentiated by dopamine and habituation of the reflex was prevented. This occurred with no change in the activity evoked in central motor neurons. These results lead us to conclude that the dopaminergic motor neuron L9 is modulating habituation in the periphery and that the central nervous system facilitatory control of the peripheral nervous system may act via a dopaminergic pathway.

scholarly journals Dendritic Spines and Development: Towards a Unifying Model of Spinogenesis—A Present Day Review of Cajal's Histological Slides and Drawings

2010 ◽  
Vol 2010 ◽  
pp. 1-29 ◽  
Author(s):  
Pablo García-López ◽  
Virginia García-Marín ◽  
Miguel Freire
Keyword(s):  
Central Nervous System ◽  
Dendritic Spines ◽  
Neural Activity ◽  
Molecular Mechanisms ◽  
Three Dimensional ◽  
Practical Interest ◽  
High Quality ◽  
Spine Development ◽  
Dimensional Reconstruction ◽  
The Central Nervous System

Dendritic spines receive the majority of excitatory connections in the central nervous system, and, thus, they are key structures in the regulation of neural activity. Hence, the cellular and molecular mechanisms underlying their generation and plasticity, both during development and in adulthood, are a matter of fundamental and practical interest. Indeed, a better understanding of these mechanisms should provide clues to the development of novel clinical therapies. Here, we present original results obtained from high-quality images of Cajal's histological preparations, stored at the Cajal Museum (Instituto Cajal, CSIC), obtained using extended focus imaging, three-dimensional reconstruction, and rendering. Based on the data available in the literature regarding the formation of dendritic spines during development and our results, we propose a unifying model for dendritic spine development.

scholarly journals Noninvasive recording of the Mauthner neurone action potential in larval zebrafish

1982 ◽  
Vol 101 (1) ◽  
pp. 83-92 ◽  
Author(s):  
J. I. Prugh ◽  
C. B. Kimmel ◽  
W. K. Metcalfe
Keyword(s):  
Neural Activity ◽  
Action Potentials ◽  
Cell Function ◽  
Recording Site ◽  
M Cell ◽  
Larval Zebrafish ◽  
System 2 ◽  
The Central Nervous System ◽  
Freely Behaving ◽  
M Spike

We describe the identification of Mauthner (M-) cell action potentials in an intact zebrafish larva, utilizing recording electrodes located outside the fish: 1. The externally recorded spike occurs at approximately the same time, and its waveform changes with recording site in the same way, as the extracellular M-spike recorded within the central nervous system. 2. The externally recorded M-spike may be readily distinguished from other forms of neural activity. 3. The M-spike can be identified in recordings from unrestrained larvae. This finding permits the direct study of M-cell function in the freely behaving animal.

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