scholarly journals Electrophysiologic Characteristics of Large Neurons in Dorsal Root Ganglia during Development and after Hind Paw Incision in the Rat

2008 ◽  
Vol 109 (1) ◽  
pp. 111-117 ◽  
Author(s):  
Douglas G. Ririe ◽  
Baogang Liu ◽  
Bridgette Clayton ◽  
Chuanyao Tong ◽  
James C. Eisenach
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Membrane Potential ◽  
Dorsal Root ◽  
Resting Membrane Potential ◽  
Similar Degree ◽  
Control Threshold ◽  
Before And After ◽  
The Central Nervous System ◽  
Large Neurons

Background Withdrawal thresholds in the paw are lower in younger animals, and incision further reduces these thresholds. The authors hypothesized that these differences result in part from changes in intrinsic electrophysiologic properties of large neurons. Methods Using isolated whole dorsal root ganglion, current clamping was performed to determine the electrophysiologic properties of large neurons before and after incision in animals aged 1 and 4 weeks. Mechanical withdrawal thresholds were used to follow paw sensitivity. Results After paw incision, withdrawal thresholds decreased to a similar degree at both ages, but returned to control threshold at 72 h only in the 1-week-old animals. The resting membrane potential was less negative and the rheobase and the resistance of the membrane were lower at baseline in the 1-week-old animals (P < 0.05). After incision, the membrane potential became more depolarized and the rheobase was less in both ages. These changes remained 72 h after the incision in both ages. Conclusion These findings suggest that lower mechanical thresholds in the younger animals may be partially attributed to the intrinsic electrophysiologic properties of the larger-diameter afferent neurons. The lack of resolution of the electrophysiologic changes in the young despite the resolution of the withdrawal response suggests that continued input from large fibers into the central nervous system may occur at this age despite the apparent resolution of behavioral changes. Further studies are needed to determine the etiology of these differences, their impact in the central nervous system, and whether theses changes can be prevented.

Effects of hypercapnia and hypoxia on inspiratory and expiratory diaphragmatic activity in conscious cats

1994 ◽  
Vol 77 (4) ◽  
pp. 1644-1652 ◽  
Author(s):  
M. Bonora ◽  
M. Boule
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Steady State ◽  
Electromyographic Activity ◽  
Large Reduction ◽  
Before And After ◽  
The Central Nervous System ◽  
State Changes ◽  
Chemical Stimuli ◽  
Adult Cats

The influence of steady-state changes in chemical stimuli on ventilation and electromyographic activity of the diaphragm during both inspiration (total DI) and expiration (total DE) was studied in unanesthetized intact adult cats before and after carotid denervation. In intact animals, during hypercapnia (2 4, and 6% CO2), tidal volume (VT) and total DI increase, whereas total DE did not consistently change. During ambient hypocapnic hypoxia (14, 12, and 10% O2), VT increased only at 10% O2, whereas total DI increased at all levels studied. Total DE increased substantially at 14% O2, persisting up to the end of expiration with 12 and 10% O2. This effect was markedly attenuated during normocapnic hypoxia. During CO hypoxemia (1,700 ppm in air), VT as well as total DI and total DE decreased because of a large reduction in inspiratory and expiratory time elicited by tachypneic breathing. The effects of hypercapnia and hypoxia persisted after carotid denervation. Therefore, 1) in contrast to hypercapnia, hypoxia markedly enhances the expiratory diaphragmatic activity, 1) this expiratory braking mechanism depends on the severity of hypoxia and is partly due to hypocapnia secondary to hypoxia; and 3) because this effect was observed after carotid denervation and during CO hypoxemia, it may arise in the central nervous system, possibly in bulbopontine structures.

Risperidone in the Treatment of Pervasive Developmental Disorder

1994 ◽  
Vol 39 (7) ◽  
pp. 400-405 ◽  
Author(s):  
Scot E. Purdon ◽  
Wilson Lit ◽  
Alain Labelle ◽  
Barry D.W. Jones
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Pervasive Developmental Disorder ◽  
Autistic Disorder ◽  
Developmental Disorder ◽  
Psychiatric Patients ◽  
High Likelihood ◽  
Before And After ◽  
History Of ◽  
The Central Nervous System

Elevated concentrations of blood serotonin have been documented in autistic children and mentally retarded adults. Antiserotonergic pharmacotherapy has been partially effective in treating a subgroup of children with autistic disorder. Therefore, the possibility is raised that an antiserotonergic treatment may be of value to adult psychiatric patients with a history of pervasive developmental disorder. Two such cases are described where the patients underwent psychiatric and neuropsychological examination before and after treatment with risperidone, a potent 5-HT2 antagonist with additional D2 antagonistic properties. Particular improvements were documented in both patients, despite long histories of cognitive compromise and high likelihood of damage to the central nervous system.

Energy metabolism of dogs after total destruction of the central nervous system

1963 ◽  
Vol 204 (2) ◽  
pp. 330-336 ◽  
Author(s):  
Paulo Enéas Galvão ◽  
Jacob Tarasantchi ◽  
Carlos Alberto E. De Magalhães
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Respiratory Muscles ◽  
Nacl Solution ◽  
Muscle Tonus ◽  
Male Adult ◽  
Total Destruction ◽  
Before And After ◽  
The Central Nervous System ◽  
Metabolic Action

The central nervous system of male adult dogs was destroyed by an injection in the cisterna magna, of a 20% NaCl solution, under 60 cm Hg pressure, during 6 min (technique of Galvão and Pereira). One hundred and sixteen O2 consumption determinations were made by analysis of the expired air or of the air pumped through the lungs, in 28 dogs, before and after CNS destruction. The metabolism level was generally well maintained during the first hours after the destruction and was materially unaltered in some dogs until death. However, in many dogs the heat production decreased more or less gradually in the later hours, and attained a mean lowering of 16.8%. The anesthesia employed, the abolition of muscle tonus and work of respiratory muscles, the respiration of the CNS, and the loss of a trophic or metabolic action of the CNS are discussed in an attempt to explain the metabolic rate of animals deprived of CNS.

Effect of Nicotine on the Synapse of the Central Nervous System

1958 ◽  
Vol 192 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Sadayuki F. Takagi ◽  
Yutaka Oomura
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Synaptic Transmission ◽  
Reflex Activity ◽  
Synaptic Delay ◽  
Synaptic Potential ◽  
Before And After ◽  
The Central Nervous System ◽  
High Concentrations

The effect of nicotine on synaptic transmission in the frog and cat spinal cord was studied. Both a regular wick electrode and a microelectrode of the Ling-Gerard type were used. The reflex activity of the bullfrog spinal cord is facilitated by 0.01% nicotine solution, but is depressed and abolished by 0.1% solution. In the cat, intravenous administration of 150 mg/kg fails to block reflex activity, but topical application does block. The intracellular potential, of both frog and cat motoneurones, shows no change in the synaptic potential after application of the drug, but the spike appears after a shorter synaptic delay and one or more additional spikes appear. When the synaptic delay becomes sufficiently short, however, all spikes suddenly disappear, leaving the still unchanged synaptic potential. Occasionally the synaptic delay is again increased just before the spike potentials disappear. The excitability of a frog motoneurone was measured, by a recording microelectrode, before and after nicotine application. The drug first increased and then decreases excitability. Epinephrine can restore a reflex discharge depressed or abolished by nicotine. It is concluded that high concentrations of nicotine block synaptic transmission in the central nervous system, acting on the cell body but not on the synaptic potential.

Su1934 Activation Status of the Central Nervous System and Lumbar Dorsal Root Ganglia in a Mouse Model of Polymicrobial Abdominal Septic Ileus

2016 ◽  
Vol 150 (4) ◽  
pp. S592-S593
Author(s):  
Sara Nullens ◽  
Steven Deleye ◽  
Joris De Man ◽  
Sven M. Francque ◽  
Steven Staelens ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mouse Model ◽  
Dorsal Root Ganglia ◽  
Dorsal Root ◽  
The Central Nervous System ◽  
Activation Status

scholarly journals Virulence profile of strains of Cryptococcus neoformans var. grubii evaluated by experimental infection in BALB/c mice and correlation with exoenzyme activity

2006 ◽  
Vol 55 (2) ◽  
pp. 139-142 ◽  
Author(s):  
Eriques Gonçalves da Silva ◽  
Francisco de Assis Baroni ◽  
Flavio César Viani ◽  
Luciana da Silva Ruiz ◽  
Rinaldo Ferreira Gandra ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cryptococcus Neoformans ◽  
Experimental Infection ◽  
The Other ◽  
Death Rates ◽  
Before And After ◽  
The Central Nervous System ◽  
Neurological Infection

To evaluate the virulence profile of strains of Cryptococcus neoformans var. grubii, 62 strains of this yeast were inoculated into BALB/c mice. It was found that 69 % of the strains were significantly more lethal to the mice and were recovered from a higher percentage (60 %) of the organs compared with the other 31 % of the strains, which were recovered from 35 % of organs tested. Those strains that provoked higher death rates were also recovered from the central nervous system at a higher rate (84 %) than the less lethal strains (32 %). This finding led to an investigation of the factors that enhanced the capacity for neurological infection and death of the animals. The results of this study suggested that environmental strains present different degrees of virulence. The correlation of exoenzyme production before and after inoculation and between the groups of mice indicated that exoenzyme production had no influence on differences in virulence among the strains studied.

A Method of Silvering the ‘Golgi Apparatus’ (Nissl Network) in Paraffin Sections of the Central Nervous System of Vertebrates

1960 ◽  
Vol s3-101 (54) ◽  
pp. 207-221
Author(s):  
G. B. DAVID ◽  
K. B. MALLION ◽  
A. W. BROWN
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Golgi Apparatus ◽  
Silver Nitrate ◽  
Metallic Silver ◽  
Paraffin Sections ◽  
Interference Microscope ◽  
Tentative Hypothesis ◽  
Before And After ◽  
The Central Nervous System

1. It was accidentally found that methods of silvering synaptic end-feet sometimes blackened Golgi's ‘internal reticular apparatus’ in neurones of the central nervous system of the cat. 2. A method of achieving this consistently was worked out: (a) paraffin sections are coated with a collodion membrane; (b) the collodion membrane is soaked in silver nitrate; (c) the silver nitrate is reduced to metallic silver with a buffered formaldehyde solution; (d) steps (b) and (c) are repeated until the sections appear quite black; (e) the silver attached to structures other than the Golgi apparatus is removed with a ferricyanide/thiosulphate bleach; (f) the section is ‘toned’ with gold chloride, fixed in thiosulphate, and washed thoroughly; (g) the section is dehydrated, cleared, and finally mounted in Canada balsam, DPX, or similar media. Results: Golgi-apparatus, black; connective-tissue fibres, black; axons, grey to black; everything else is light grey or colourless. 3. A tentative hypothesis is advanced to explain the results obtained. 4. The following advantages are claimed for the new method: the cytoplasmic reticulum thus blackened resembles that seen in living neurones with the interference microscope; special methods of fixation are not required; the cytoplasmic reticulum of given cells can be studied before and after silvering; and serial sections of the same piece of tissue can be used for histochemical purposes.

Sign in / Sign up

Export Citation Format

Share Document