Effects of lesions to the parafascicular nuclei of the thalamus on the development of a conditioned active escape reflex in rats

1998 ◽  
Vol 28 (4) ◽  
pp. 419-422 ◽  
Author(s):  
T. A. Dyubkacheva
Keyword(s):  
1998 ◽  
Vol 28 (5) ◽  
pp. 490-492
Author(s):  
E. V. Buzinova ◽  
Zh. E. Slesareva ◽  
M. F. Obukhova ◽  
I. P. Ashmarin

Development ◽  
2001 ◽  
Vol 128 (6) ◽  
pp. 883-894 ◽  
Author(s):  
B.E. Vogel ◽  
E.M. Hedgecock

him-4 mutations cause a novel syndrome of tissue fragility, defective cell migration and chromosome instability in Caenorhabditis elegans. Null mutants have abnormal escape reflex, mispositioning of the vas deferens and uterus, and mitotic chromosome loss and multinucleate cells in the germline. The him-4 gene product, hemicentin, is a conserved extracellular matrix protein with 48 tandem immunoglobulin repeats flanked by novel terminal domains. Secreted from skeletal muscle and gonadal leader cells, hemicentin assembles into fine tracks at specific sites, where it contracts broad regions of cell contact into oriented linear junctions. Some tracks organize hemidesmosomes in the overlying epidermis. Hemicentin tracks facilitate mechanosensory neuron anchorage to the epidermis, gliding of the developing gonad along epithelial basement membranes and germline cellularization.


1969 ◽  
Vol 53 (2) ◽  
pp. 211-237 ◽  
Author(s):  
A. A. Auerbach ◽  
M. V. L. Bennett

The adductor muscles of the pectoral fins of the hatchetfish Gasteropelecus are innervated by bilateral pools of about 40 motoneurons which lie primarily in the first spinal segment. A pair of giant fibers on each side of the medulla send processes ventroposteriorly to the motoneuron pools. Electrophysiological evidence indicates that giant fibers are presynaptic to ipsilateral motoneurons, but not to contralateral ones. Transmission across the giant fiber, motoneuron synapse is electrically mediated as is indicated by direct measurement of electrotonic spread in either direction across the synapse, and by the extremely short latency of the giant fiber postsynaptic potentials (PSP's) in the motoneuron. The coupling resistance across the synapse was calculated from measurements of input and transfer resistance. The coupling resistance rectifies in such a way as to facilitate spread of depolarization from giant fiber to motoneuron, and to oppose transmission in the opposite direction. As a consequence of rectification, the giant fiber PSP in a motoneuron is augmented by hyperpolarization of the motoneuron. The coupling resistance calculated on the basis of this effect is in good agreement with calculations from input and transfer resistance data. Rectification at the electrotonic synapses may permit the motoneurons to act in small swimming movements as well as to fire synchronously in an extremely fast escape reflex mediated by Mauthner and giant fibers.


2020 ◽  
Author(s):  
Atulya Srisudarshan Ram Iyengar ◽  
Hongyu Ruan ◽  
Chun-Fang Wu

AbstractWe examined several sensory-motor processing circuits in Drosophila across the lifespan and uncovered distinctive age-resilient and age-vulnerable trajectories in their established functional properties. We observed relatively little deterioration toward the end of lifespan in the giant-fiber (GF) and downstream circuit elements responsible for the jump-and-flight escape reflex. In contrast, we found substantial age-dependent modifications in the performance of GF inputs and other circuits driving flight motoneuron activities. Importantly, in high temperature (HT)-reared flies (29 °C), the characteristic age-dependent progression of these properties was largely maintained, albeit over a compressed time scale, lending support for the common practice of expediting Drosophila aging studies by HT rearing. We discovered shortened lifespans in Cu2+/Zn2+Superoxide Dismutase 1 (Sod) mutant flies were accompanied by alterations distinct from HT-reared flies, highlighting differential effects of oxidative vs temperature stressors. This work also establishes several age-vulnerable parameters that may serve as quantitative neurophysiological landmarks for aging in Drosophila.


2020 ◽  
Author(s):  
Gang Xu ◽  
Yikun Shi ◽  
Binda Sun ◽  
Lu Liu ◽  
Guoji E ◽  
...  

Abstract Background: Studies revealed the protective effect of DL-3-n-butylphthalide (NBP) against ischemic hypoxia diseases. However, the role of NBP in animals with hypobaric hypoxia is elusive. This study investigated the effect of NBP on animals with acute and chronic hypobaric hypoxia.Methods: SD rats and Kunming mice administrated with NBP (90, 180 and 360 mg/kg for mice, and 60, 120, and 240 mg/kg for rats) were located in 10,000 m hypobaric hypoxia chamber. And survival analysis of animals implied that NBP could significantly improve survival percent at 30 min. Then, treated animals were evaluated for exhaustive time and exhaustive distance in forced exercise wheel-track treadmill and treadmill running experiments at 5,800 m for 3 or 21 days, to evaluate physical functions. Rats were also evaluated for times of active escape, average time of active escape, time of passive escape, and average time of passive escape in a shuttle-box experiment at 5,800 m for 7 or 28 days, to evaluate cognitive functions. ATP level was evaluated in the gastrocnemius muscle and maloaldehyde (MDA), superoxide dismutase (SOD), hydrogen peroxide (H2O2), lactate, and glutathione peroxiase (GSH-Px) measurements and routine blood tests were detected.Results: Exhaustive time for rats (NBP, 120 and 240 mg/kg) and exhaustive time and distance for mice (NBP, 90 mg/kg) significantly increased under acute hypoxia. And NBP treatment significantly increased the exhaustive time for rats under chronic hypoxia. Moreover, NBP of 120 and 240 mg/kg significantly increased the average time of passive escape under acute and chronic hypoxia. These results suggested that NBP could improve physical and cognitive functions under acute and chronic hypobaric hypoxia. Furthermore, the levels of MDA and H2O2 decreased but those of SOD and GSH-Px increased under acute and chronic hypoxia. Furthermore, the content of ATP significantly increased, while lactate level significantly decreased. The results presented that NBP could regulate redox homeostasis and improve energy metabolism.Conclusion: NBP could improve physical and cognitive functions under acute and chronic hypobaric hypoxia by increasing anti-oxidative capacity and energy supply.


1997 ◽  
Vol 17 (2) ◽  
pp. 709-716 ◽  
Author(s):  
Franklin B. Krasne ◽  
Ashkan Shamsian ◽  
Raghavendra Kulkarni

1965 ◽  
Vol 42 (2) ◽  
pp. 307-322 ◽  
Author(s):  
FRANKLIN B. KRASNE

1. Branchiomma's rapid escape from tactile stimuli is mediated by the pair of giant nerve axons which run the length of the body above the ventral nerve cord. 2. The giant neurons are connected by very stable, polarized junctions to giant motor axons. 3. The giant-fibre escape reflex fails if tactile stimuli are repeated; a non-giant system which continues to cause slower escape eventually fails also. 4. Recovery from reflex failure is slow. 5. The failure of the rapid escape reflex occurs prior to the giant fibre. It is not primarily due to sensory ending accommodation. It cannot be caused by direct stimulation of the giant fibres.


1973 ◽  
Vol 59 (2) ◽  
pp. 383-403
Author(s):  
N. F. ZILBER-GACHELIN ◽  
M. P. CHARTIER

1. The synaptic transfer properties within the 3rd thoracic ganglion (T.G.) from the abdominal cord axons to the motoneurones has been studied in the cockroach. This ganglion was completely de-afferented except for motor nerve 4, whose links with the muscles of the posterior legs were left intact. 2. The response of one of these nerves to electrical stimulation of the abdominal cord involves activation of 2 types of units: (a) Slow excitatory fibres which have a tonic discharge and respond to each lowthreshold abdominal cord stimulation by a transient increase of this firing rate; these units are responsible for muscular tonus and for low amplitude movements (startle reactions). (b) Fast excitatory fibres, which have no tonic discharge and require for their activation higher intensity and frequency of stimulation, i.e. an important temporal and spatial summation. They are responsible for larger and more rapid movements. They fire without any precise chronological relation with the stimuli, often in bursts which continue after the end of the stimulations and cause sudden rhythmic movements. 3. During repetition of the stimuli, the two types of synaptic pathways show both habituation and facilitation through temporal summation and post-tetanic potentiation. These two phenomena persist after the end of the stimulations and have long (minutes) but different time courses. Moreover, habituation always prevails over facilitation if stimulations are continued during a sufficient time. These antagonistic properties existing at the same time might explain the complex way in which the motor responses develop with the application of repetitive trains of stimuli to the cord. 4. The role of these properties in the changes of the reflex motor responses to successive air puffs applied to the cerci has been studied. These properties appear to be responsible for the sensitization of the responses which can be sometimes observed. They lead, in conjunction with the habituation properties of the 6th abdominal ganglion (A.G.), to the disappearance of the escape reflex involving firing of both fast and slow fibres. Finally, they seem to have a minor role in habituation of the startle reactions (involving firing of only the slow fibres) which would be mainly due to the 6th A.G. habituability.


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