Functional role of median longitudinal fasciculus in evoked conjugate ocular deviations in cats

1961 ◽  
Vol 200 (5) ◽  
pp. 919-922 ◽  
Author(s):  
Jane E. Hyde ◽  
Margaret A. Slusher
Keyword(s):  
Zona Incerta ◽  
Single Group ◽  
Functional Deficits ◽  
Common Path ◽  
Nuclear Complex ◽  
Ocular Movements ◽  
Vestibular Nuclear Complex ◽  
The Common ◽  
Stimulation Of

Functional deficits of evoked conjugate ocular movements were assessed following acute surgical interruption of the median longitudinal fasciculus (MLF) in cats prepared as encéphale isolés. a) In horizontal deviations, adduction evoked by stimulation of dorsal midbrain, zona incerta and medial reticular substance of medulla was abolished by bilateral section of the MLF at or anterior to the level of the 6th nucleus. Unilateral sections differentially abolished adduction from the three stimulated areas. Abduction from dorsal midbrain stimulation required a higher voltage following section of MLF between or just posterior to the sixth nuclei. b) Conjugate ocular torsion evoked by stimulation of zona incerta was significantly altered by sections of internuclear MLF as well as by coagulating lesions in the vestibular nuclear complex. Results indicate first that no single group of fibers in the MLF serves as ‘the common path’ for ocular adduction in all types of horizontal conjugate movements. Second, the degree of torsion induced by stimulation of the zona incerta is at least partially dependent on vestibulomesencephalic impulses ascending the MLF.

Role of the vestibular nuclear complex in facilitating the jaw-opening reflex following stimulation of the red nucleus

2016 ◽  
Vol 110 ◽  
pp. 29-36 ◽  
Author(s):  
Yoshihide Satoh ◽  
Ken’Ichi Ishizuka ◽  
Mutsumi Takahashi ◽  
Shin-ichi Iwasaki
Keyword(s):  
Red Nucleus ◽  
Nuclear Complex ◽  
Jaw Opening ◽  
Vestibular Nuclear Complex ◽  
Jaw Opening Reflex ◽  
Stimulation Of

The zona incerta modulates spontaneous spike-wave discharges in the rat

2013 ◽  
Vol 109 (10) ◽  
pp. 2505-2516 ◽  
Author(s):  
Fu-Zen Shaw ◽  
Yi-Fang Liao ◽  
Ruei-Feng Chen ◽  
Yu-Hsing Huang ◽  
Rick C. S. Lin
Keyword(s):  
Functional Role ◽  
Significant Inhibition ◽  
Zona Incerta ◽  
Obvious Effect ◽  
Spike Wave Discharges ◽  
Long Evans ◽  
Oscillation Frequencies ◽  
Spike Wave ◽  
Stimulation Of

The contribution of the zona incerta (ZI) of the thalamus on spike-wave discharges (SWDs) was investigated. Chronic recordings of bilateral cortices, bilateral vibrissa muscle, and unilateral ZI were performed in Long-Evans rats to examine the functional role of SWDs. Rhythmic ZI activity appeared at the beginning of SWD and was accompanied by higher-oscillation frequencies and larger spike magnitudes. Bilateral lidocaine injections into the mystacial pads led to a decreased oscillation frequency of SWDs, but the phenomenon of ZI-related spike magnitude enhancement was preserved. Moreover, 800-Hz ZI microstimulation terminates most of the SWDs and whisker twitching (WT; >80%). In contrast, 200-Hz ZI microstimulation selectively stops WTs but not SWDs. Stimulation of the thalamic ventroposteriomedial nucleus showed no obvious effect on terminating SWDs. A unilateral ZI lesion resulted in a significant reduction of 7- to 12-Hz power of both the ipsilateral cortical and contralateral vibrissae muscle activities during SWDs. Intraincertal microinfusion of muscimol showed a significant inhibition on SWDs. Our present data suggest that the ZI actively modulates the SWD magnitude and WT behavior.

scholarly journals Hormesis in Plants: The Role of Oxidative Stress, Auxins and Photosynthesis in Corn Treated with Cd or Pb

2020 ◽  
Vol 21 (6) ◽  
pp. 2099 ◽  
Author(s):  
Eugeniusz Małkowski ◽  
Krzysztof Sitko ◽  
Michał Szopiński ◽  
Żaneta Gieroń ◽  
Marta Pogrzeba ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Shoot Growth ◽  
Photosynthetic Apparatus ◽  
Growth Stimulation ◽  
Photosynthetic Parameters ◽  
Toxic Substances ◽  
Wide Range ◽  
The Common ◽  
Stimulation Of

Hormesis, which describes the stimulatory effect of low doses of toxic substances on growth, is a well-known phenomenon in the plant and animal kingdoms. However, the mechanisms that are involved in this phenomenon are still poorly understood. We performed preliminary studies on corn coleoptile sections, which showed a positive correlation between the stimulation of growth by Cd or Pb and an increase in the auxin and H2O2 content in the coleoptile sections. Subsequently, we grew corn seedlings in hydroponic culture and tested a wide range of Cd or Pb concentrations in order to determine hormetic growth stimulation. In these seedlings the gas exchange and the chlorophyll a fluorescence, as well as the content of chlorophyll, flavonol, auxin and hydrogen peroxide, were measured. We found that during the hormetic stimulation of growth, the response of the photosynthetic apparatus to Cd and Pb differed significantly. While the application of Cd mostly caused a decrease in various photosynthetic parameters, the application of Pb stimulated some of them. Nevertheless, we discovered that the common features of the hormetic stimulation of shoot growth by heavy metals are an increase in the auxin and flavonol content and the maintenance of hydrogen peroxide at the same level as the control plants.

Central nystagmus. III. Functional correlations of mesodiencephalic nystagmogenic center

1959 ◽  
Vol 197 (2) ◽  
pp. 454-460 ◽  
Author(s):  
F. Bergmann ◽  
J. Lachmann ◽  
M. Monnier ◽  
P. Krupp
Keyword(s):  
Electrical Stimulation ◽  
Eye Movements ◽  
Vestibular Nuclei ◽  
Rabbit Brain ◽  
Vestibular Nystagmus ◽  
Posterior Commissure ◽  
Common Substrate ◽  
The Common ◽  
Stimulation Of

Transverse cuts at various levels of the rabbit brain stem have different effects on vestibular nystagmus and on central nystagmus elicited by electrical stimulation of the mesodiencephalic nystagmogenic area. While transections rostral to the sensitive region enhance both, probably by elimination of inhibitory influences from cortex or retina, transections caudal to this region, but rostral to the colliculi, abolish central nystagmus only. Transections at the level of the inferior colliculus abolish vestibular nystagmus only, while intermediate cuts may eliminate either response. When central nystagmus alone survives, its character is changed in a specific way indicating the important role of the vestibular nuclei in normal central nystagmus. These observations lead to an approximate localization of the common substrate for conjugate eye movements involved both in central and vestibular nystagmus. Longitudinal cuts through the posterior commissure provoke a temporary disconjugated nystagmus not described hitherto.

Electrical stimulation of the posteromedial thalamus modulates breathing in unanesthetized fetal sheep

2004 ◽  
Vol 96 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Brian J. Koos ◽  
Yoshikazu Kawasaki ◽  
Ashwinii Hari ◽  
Fanor Bohorquez ◽  
Calvin Jan ◽  
...  
Keyword(s):  
Zona Incerta ◽  
Thalamic Nuclei ◽  
Electrode Arrays ◽  
Fetal Sheep ◽  
Restricted Area ◽  
Expiratory Time ◽  
Nuclear Complex ◽  
Adjacent Structures ◽  
Central Gray ◽  
Stimulation Of

Having previously shown that lesions in the posteromedial group of thalamic nuclei abolish hypoxic inhibition of fetal breathing, we devised this study to identify thalamic loci that depress breathing by focal stimulation of specific sectors of the caudal thalamus and adjacent structures. Multipolar electrode arrays consisting of a series of eight stimulation contacts at 1.25-mm intervals were implanted vertically through guide cannulae into the caudal diencephalon of 12 chronically catheterized fetal sheep (>0.8 term), and central neural tissue was stimulated between adjacent contacts. Each site was stimulated repeatedly with increasing current searching for spatial and stimulus strength parameters for a reliable alteration in respiratory rate. Respiratory period increased when stimulation involved areas of the parafascicular nuclear complex (Pf), which more than doubled the mean period compared with the baseline of 0.90 ± 0.19 s. The change in respiratory period was due to an increase in expiratory time, whereas inspiratory time and breath amplitude were not significantly affected. Breathing period and expiratory time were also increased when the stimulations involved the intralaminar wing surrounding the mediodorsal nucleus, the rostral central gray, zona incerta, and ventral tegmental area. Reductions in respiratory frequency occurred less consistently, with stimulation involving surrounding zones including the sub-Pf, ventromedial nucleus, and ventrobasal nuclear complex. These findings support the hypothesis that a restricted area of the posteromedial thalamus (principally Pf) constitutes part of a neuronal circuitry that modulates respiratory motoneurons.

Neuronal locus and cellular signaling for stimulation of ileal giant migrating and phasic contractions

2003 ◽  
Vol 284 (5) ◽  
pp. G789-G797 ◽  
Author(s):  
Sushil K. Sarna
Keyword(s):  
Ruthenium Red ◽  
Signaling Cascades ◽  
Receptor Subtype ◽  
Calcitonin Gene ◽  
Intracellular Ca ◽  
The Common ◽  
Higher Doses ◽  
Pkc Activation ◽  
Stimulation Of

We investigated the neuronal locus, the role of PKC activation, and utilization of extracellular Ca2+ and intracellular Ca2+ release in smooth muscle cells for the generation of giant migrating contractions (GMCs) and rhythmic phasic contractions (RPCs) in intact normal and inflamed canine ileum. Calcitonin gene-related peptide (CGRP), administered close intra-arterially, stimulated GMCs at higher doses and RPCs at smaller doses. These effects were blocked by prior close intra-arterial infusions of CGRP8–37, atropine, hexamethonium, and TTX but not by tachykinin, serotonin, and histaminergic receptor subtype antagonists. Both types of contractions were blocked by verapamil in normal and inflamed ileums. Dantrolene and ruthenium red blocked only the RPCs in normal ileum but blocked both GMCs and RPCs in the inflamed ileum. PKC inhibition by chelerythrine blocked GMCs only in inflamed ileum but blocked RPCs in both normal and inflamed ileums. The inhibition of phospholipase C by neomycin blocked both RPCs and GMCs in normal and inflamed ileums. In conclusion, acetylcholine is the common neurotransmitter for the stimulation of both GMCs and RPCs, but the signaling cascades for their stimulation are partially divergent, and they differ also in the normal and inflamed states.

Modulation of the jaw-opening reflex by stimulation of the vestibular nuclear complex in rats

2009 ◽  
Vol 457 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Yoshihide Satoh ◽  
Ken’Ichi Ishizuka ◽  
Toshiki Murakami
Keyword(s):  
Nuclear Complex ◽  
Jaw Opening ◽  
Vestibular Nuclear Complex ◽  
Jaw Opening Reflex ◽  
Stimulation Of

scholarly journals Palatability: response to nutritional need or need-free stimulation of appetite?

2004 ◽  
Vol 92 (S1) ◽  
pp. S3-S14 ◽  
Author(s):  
Martin R. Yeomans ◽  
John E. Blundell ◽  
Micah Leshem
Keyword(s):  
Brain Structures ◽  
Neural Systems ◽  
Short Term ◽  
Motivational System ◽  
Nutritional Deficit ◽  
The Common ◽  
Disparate Data ◽  
Common Observation ◽  
Stimulation Of

The traditional view of palatability was that it reflected some underlying nutritional deficit and was part of a homeostatically driven motivational system. However, this idea does not fit with the common observation that palatability can lead to short-term overconsumption. Here, we attempt to re-evaluate the basis of palatability, first by reviewing the role of salt-need both in the expression of liking for salty tastes, and paradoxically, in dissociating need from palatability, and second by examining the role of palatability in short-term control of appetite. Despite the clarity of this system in animals, however, most salt (NaCl) intake in man occurs in a need-free state. Similar conclusions can be drawn in relation to the palatability of food in general. Importantly, the neural systems underlying the hedonic system relating to palatability and homeostatic controls of eating are separate, involving distinct brain structures and neurochemicals. If palatability was a component of homeostatic control, reducing need-state should reduce palatability. However, this is not so, and if anything palatability exerts a stronger stimulatory effect on eating when sated, and over-consumption induced by palatability may contribute to obesity. Differential responsivity to palatability may be a component of the obese phenotype, perhaps through sensitisation of the neural structures related to hedonic aspects of eating. Together, these disparate data clearly indicate that palatability is not a simple reflection of need state, but acts to promote intake through a distinct hedonic system, which has inputs from a variety of other systems, including those regulating need. This conclusion leads to the possibility of novel therapies for obesity based on modulation of hedonic rather than homeostatic controls. Potential developments are discussed.

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