Spatial Distribution and Discharge Characteristics of Superior Colliculus Neurons Antidromically Activated From the Omnipause Region in Monkey

1997 ◽  
Vol 78 (4) ◽  
pp. 2221-2225 ◽  
Author(s):  
Neeraj J. Gandhi ◽  
Edward L. Keller
Keyword(s):  
Spatial Distribution ◽  
Superior Colliculus ◽  
Oculomotor Control ◽  
Discharge Characteristics ◽  
Spatially Distributed ◽  
Superior Colliculus Neurons ◽  
Rostral Region ◽  
And Control ◽  
Omnipause Neurons

Gandhi, Neeraj J. and Edward L. Keller. Spatial distribution and discharge characteristics of superior colliculus neurons antidromically activated from the omnipause region in monkey. J. Neurophysiol. 78: 2221–2225, 1997. One proposed role of the superior colliculus (SC) in oculomotor control is to suppress or excite the activity of brain stem omnipause neurons (OPNs) to initiate or terminate saccades, respectively. Although connections from the SC to the OPNs have been demonstrated, the spatial distribution and discharge characteristics of the projecting neurons from the SC remain unknown. We mapped the spatial distribution of the deeper-layer neurons of the SC by stimulating the region of the OPNs to identify antidromic projections and found that the density of direct projections from the SC to the OPNs was greatest in the most rostral region and decreased gradually for more caudal sites. On the basis of saccade-related discharge characteristics, the antidromically driven neurons were predominantly fixation and buildup neurons. The spatially distributed SC projections to the OPNs and the discharge characteristics of the SC neurons suggest that the direct projections from SC to OPNs are excitatory. Finally, we propose how excitation and disfacilitation from SC activity can contribute to modulation of OPN response and control saccades.

Comparison of the Discharge Characteristics of Brain Stem Omnipause Neurons and Superior Colliculus Fixation Neurons in Monkey: Implications for Control of Fixation and Saccade Behavior

1998 ◽  
Vol 79 (2) ◽  
pp. 511-528 ◽  
Author(s):  
Stefan Everling ◽  
Martin Paré ◽  
Michael C. Dorris ◽  
Douglas P. Munoz
Keyword(s):  
Superior Colliculus ◽  
Brain Stem ◽  
Discharge Rate ◽  
Excitatory Input ◽  
Visual Fixation ◽  
Activity Level ◽  
Physiological Data ◽  
Discharge Characteristics ◽  
Omnipause Neurons ◽  
Saccade Generation

Everling, Stefan, Martin Paré, Michael C. Dorris, and Douglas P. Munoz. Comparison of the discharge characteristics of brain stem omnipause neurons and superior colliculus fixation neurons in monkey: implications for control of fixation and saccade behavior. J. Neurophysiol. 79: 511–528, 1998. Fixation neurons (SCFNs) in the rostral pole of the superior colliculus (SC) and omnipause neurons (OPNs) in the nucleus raphe interpositus (rip) in the pons share similar discharge properties. Both types of neurons discharge tonically during periods of visual fixation and pause for saccadic eye movements, and their activation by electrical stimulation suppresses saccade generation. On the basis of these similarities and the projection from the rostral SC to the rip, it was hypothesized that SCFNs provide a major excitatory input to OPNs. We investigated the role and relationship of SCFNs and OPNs with respect to both fixation behavior and saccade generation by comparing their activity recorded in the same monkeys performing a gap saccade task. In this task, the central fixation point was extinguished 200 ms before the presentation of an eccentric saccadic target, and the discharges of OPNs and SCFNs were contrasted during visual fixation, nonvisual (gap) fixation, and saccade generation. During visual fixation, the mean discharge rate of OPNs was higher and more regular than that of SCFNs. During the gap period, SCFNs decreased their discharge rate before target appearance, whereas no change in discharge rate was observed in OPNs. For both SCFNs and OPNs, the activity level before target appearance was not correlated to saccadic reaction time. In contrast to SCFNs, several OPNs responded with a transient phasic increase in discharge immediately after the target presentation. Before their saccade-related pause, there was a gradual reduction in the activity of SCFNs, whereas OPNs had an abrupt cessation of discharge. SCFNs paused earlier than OPNs, but the OPN pause onset was better synchronized to saccade onset than the SCFN pause onset. OPNs resumed firing after their pause in activity earlier than SCFNs, and the OPN pause end was better synchronized to saccade end than the SCFN pause end. These physiological data reveal differences in the discharge properties of SCFNs and OPNs that are irreconcilable with the hypothesis that the discharge pattern of OPNs reflects simply the excitatory input from SCFNs. It is most likely that additional inputs to OPNs compensate for the reduction in discharge of SCFNs during these periods.

Two Cortical Areas Mediate Multisensory Integration in Superior Colliculus Neurons

2001 ◽  
Vol 85 (2) ◽  
pp. 506-522 ◽  
Author(s):  
Wan Jiang ◽  
Mark T. Wallace ◽  
Huai Jiang ◽  
J. William Vaughan ◽  
Barry E. Stein
Keyword(s):  
Superior Colliculus ◽  
Anterior Ectosylvian Sulcus ◽  
Cortical Areas ◽  
Reversible Deactivation ◽  
Response Enhancement ◽  
Multisensory Enhancement ◽  
Superior Colliculus Neurons ◽  
Cat Superior Colliculus ◽  
Single Modality

The majority of multisensory neurons in the cat superior colliculus (SC) are able to synthesize cross-modal cues (e.g., visual and auditory) and thereby produce responses greater than those elicited by the most effective single modality stimulus and, sometimes, greater than those predicted by the arithmetic sum of their modality-specific responses. The present study examined the role of corticotectal inputs from two cortical areas, the anterior ectosylvian sulcus (AES) and the rostral aspect of the lateral suprasylvian sulcus (rLS), in producing these response enhancements. This was accomplished by evaluating the multisensory properties of individual SC neurons during reversible deactivation of these cortices individually and in combination using cryogenic deactivation techniques. Cortical deactivation eliminated the characteristic multisensory response enhancement of nearly all SC neurons but generally had little or no effect on a neuron's modality-specific responses. Thus, the responses of SC neurons to combinations of cross-modal stimuli were now no different from those evoked by one or the other of these stimuli individually. Of the two cortical areas, AES had a much greater impact on SC multisensory integrative processes, with nearly half the SC neurons sampled dependent on it alone. In contrast, only a small number of SC neurons depended solely on rLS. However, most SC neurons exhibited dual dependencies, and their multisensory enhancement was mediated by either synergistic or redundant influences from AES and rLS. Corticotectal synergy was evident when deactivating either cortical area compromised the multisensory enhancement of an SC neuron, whereas corticotectal redundancy was evident when deactivation of both cortical areas was required to produce this effect. The results suggest that, although multisensory SC neurons can be created as a consequence of a variety of converging tectopetal afferents that are derived from a host of subcortical and cortical structures, the ability to synthesize cross-modal inputs, and thereby produce an enhanced multisensory response, requires functional inputs from the AES, the rLS, or both.

scholarly journals Symbolic Cue-Driven Activity in Superior Colliculus Neurons in a Peripheral Visual Choice Task

2006 ◽  
Vol 95 (6) ◽  
pp. 3585-3595 ◽  
Author(s):  
Kyoung-Min Lee ◽  
Edward L. Keller
Keyword(s):  
Superior Colliculus ◽  
Target Selection ◽  
Saccadic Eye Movements ◽  
Spatial Location ◽  
Choice Response ◽  
Visual Response ◽  
Superior Colliculus Neurons ◽  
Response Task ◽  
And Control

Recent evidence implicates the superior colliculus (SC) in cognitive processes, such as target selection and control of spatial attention, in addition to the execution of saccadic eye movements. We report here the presence of a cognitive response in some cells in the SC in a task that requires the long-term association of spatial location with an arbitrary color. In this study, using a visual choice response task, we demonstrate that visuomotor neurons in the SC were activated by the appearance of a central symbolic cue delivered outside of the visual response fields of the recorded neurons. This procedure ensures that cognitively generated activity in these SC cells is not confounded with modulation of activity from previous visual stimuli that appeared in the response field of the neurons. The experiments suggest that cognitive signals can activate SC cells by themselves instead of only being able to modulate activities already evoked by visual events. Furthermore, a substantial fraction of these cells accurately reflected cue-aligned target selection in advance of saccade initiation. Our results add further support to other studies that have demonstrated that internally generated signals exist in SC cells.

Morphogenesis of a New Human Herpes-Type Virus Isolate (Sasha Virus)

1973 ◽  
Vol 31 ◽  
pp. 592-593
Author(s):  
R. F. Zeigel ◽  
W. Munyon
Keyword(s):  
Virus Isolate ◽  
Calf Serum ◽  
Uranyl Acetate ◽  
Human Herpes ◽  
Human Embryonic Lung ◽  
Human Herpes Virus ◽  
Intracytoplasmic Inclusions ◽  
Hel Cells ◽  
And Control

In continuing studies on the role of viruses in biochemical transformation, Dr. Munyon has succeeded in isolating a highly infectious human herpes virus. Fluids of buccal pustular lesions from Sasha Munyon (10 mo. old) uiere introduced into monolayer sheets of human embryonic lung (HEL) cell cultures propagated in Eagles’ medium containing 5% calf serum. After 18 hours the cells exhibited a dramatic C.P.E. (intranuclear vacuoles, peripheral patching of chromatin, intracytoplasmic inclusions). Control HEL cells failed to reflect similar changes. Infected and control HEL cells were scraped from plastic flasks at 18 hrs. of incubation and centrifuged at 1200 × g for 15 min. Resultant cell packs uiere fixed in Dalton's chrome osmium, and post-fixed in aqueous uranyl acetate. Figure 1 illustrates typical hexagonal herpes-type nucleocapsids within the intranuclear virogenic regions. The nucleocapsids are approximately 100 nm in diameter. Nuclear membrane “translocation” (budding) uias observed.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

From Container to Claustrum: Projective Identification in Couples

2014 ◽  
Vol 4 (2) ◽  
Author(s):  
Tamara Feldman
Keyword(s):  
Psychological Health ◽  
Projective Identification ◽  
The Self ◽  
The Other ◽  
Intimate Partners ◽  
And Control ◽  
The Relationship ◽  
As If

This paper is a contribution to the growing literature on the role of projective identification in understanding couples' dynamics. Projective identification as a defence is well suited to couples, as intimate partners provide an ideal location to deposit unwanted parts of the self. This paper illustrates how projective identification functions differently depending on the psychological health of the couple. It elucidates how healthier couples use projective identification more as a form of communication, whereas disturbed couples are inclined to employ it to invade and control the other, as captured by Meltzer's concept of "intrusive identification". These different uses of projective identification affect couples' capacities to provide what Bion called "containment". In disturbed couples, partners serve as what Meltzer termed "claustrums" whereby projections are not contained, but imprisoned or entombed in the other. Applying the concept of claustrum helps illuminate common feelings these couples express, such as feeling suffocated, stifled, trapped, held hostage, or feeling as if the relationship is killing them. Finally, this paper presents treatment challenges in working with more disturbed couples.

The Estimation of prostate specific antigen (PSA) concentrations in patients with prostatitis by fully automated ELISA technique.

2020 ◽  
Vol 3 (11) ◽  
pp. 1100-1104
Author(s):  
Hussein Naeem Aldhaheri ◽  
Ihsan Edan AlSaimary ◽  
Murtadha Mohammed ALMusafer
Keyword(s):  
Personal Information ◽  
Receptor Gene ◽  
Specific Antigen ◽  
Gene Clusters ◽  
Control Group ◽  
P Value ◽  
Group Data ◽  
Elisa Technique ◽  
And Control

      The Aim of this study was to determine Immunogenetic expression of  Toll-like receptor gene clusters related to prostatitis, to give acknowledge about Role of TLR in prostatitis immunity in men from Basrah and Maysan provinces. A case–control study included 135 confirmed prostatitis patients And 50 persons as a control group. Data about age, marital status, working, infertility, family history and personal information like (Infection, Allergy, Steroid therapy, Residency, Smoking, Alcohol Drinking, Blood group, Body max index (BMI) and the clinical finding for all patients of Prostatitis were collected. This study shows the effect of PSA level in patients with prostatitis and control group, with P-value <0.0001 therefore the study shows a positive significant between elevated PSA levels and Prostatitis.

Sign in / Sign up

Export Citation Format

Share Document