scholarly journals Long Term Induction of Kindled Seizures in Rats: Interhemispheric Factors

Author(s):  
José N. Nobrega ◽  
John Gaito

SUMMARY:Previous research indicated that sequential alternation of stimulation of certain homologous brain areas via chronically implanted electrodes resulted in oscillation of high and low latencies for convulsions. This phenomenon suggested the establishment of interhemispheric facilitatory-inhibitory effects as a result of repeated stimulation of the two brain sites. In the present study, the latency oscillation pattern was observed in split-brain rats as well as in bilaterally stimulated controls, but not in rats stimulated on one side only. Significant differences were observed between split-brain and control rats in terms of initial kindling rates, duration of convulsions and type of oscillation. Results are discussed in the context of possible interhemispheric mechanisms involved in long term kindling.

1998 ◽  
Vol 118 (4) ◽  
pp. 512-522
Author(s):  
Randal C. Paniello ◽  
J. David Dahm

Experimental induced phonation in the dog has been used in short-term studies by several investigators and has proved quite useful in laryngeal research. In this study a long-term canine phonation model is described that uses permanently implanted electrodes on the superior and recurrent laryngeal nerves. A serial induced phonation model has not been previously reported and is needed for laryngeal research in which voice results are a primary end point. Inexpensive, reliable, nontoxic electrodes were designed and fabricated. The laryngeal nerves were found to be quite susceptible to injury, necessitating a series of changes in electrode design. Electrode durability and laryngeal nerve viability improved with each design modification; the final design gave a recurrent laryngeal nerve viability rate of 100% at 6 weeks, 83% at 9 weeks, and 73% at 12 weeks. Induced phonation was successfully produced on a repeated basis by stimulating the recurrent laryngeal nerves while passing air through the larynx, in 22 (95.6%) of 23 animals. Stimulation of the superior laryngeal nerves increased vocal fold length and tension but was not required for phonation. Technical aspects of chronic implantation and stimulation of the laryngeal nerves are discussed. The development and successful long-term implantation of electrodes on the laryngeal nerves and their use in repeated induced phonation have not been reported previously.


1975 ◽  
Vol 65 (2) ◽  
pp. 163-176 ◽  
Author(s):  
K. BOER ◽  
D. W. LINCOLN ◽  
D. F. SWAAB

SUMMARY Labour was studied in 69 primiparous and multiparous rats by continuous observation and by the recording of intra-uterine activity. The effect of electrical stimulation of the neurohypophysis with stimulation parameters selected to create a pulsatile release of oxytocin was investigated. Stimulation was applied to the neurohypophysis through chronically implanted electrodes every 5 min, in 45 min sessions, from noon on Day 21 of gestation and at 3 h intervals thereafter. Electrical stimulation successfully promoted (or induced) the onset and facilitated the course of labour. Stimulation at 12.00 h on Day 21, or at a subsequent stimulation session 3, 6, 9 or more hours later, promoted an immediate increase in the frequency and amplitude of uterine contractions. Overt signs of abdominal straining followed within 5–30 min and the first pup was delivered shortly thereafter. These 'induced' deliveries were almost identical to those displayed by control rats; labour continued to completion despite the termination of the stimulation session after 45 min. By contrast, one third of the stimulated animals displayed an interrupted pattern of labour in which events virtually ceased for 30–60 min when stimulation was terminated. Stimulation, however, only advanced labour by 1–2 h in relation to control animals; this was not statistically significant. Stimulation accelerated the delivery of the first 5 pups in each litter. In both stimulated and control animals, the birth intervals declined over these first few deliveries to reach the lowest values of 5–6 min throughout the remainder of labour. The most common litter size was 12 pups. The distribution of labour on Day 21 and 22 was bimodal. Seventy per cent of the animals gave birth between 12.00 and 18.00 h on Day 21, a few gave birth during the following night and the remainder formed a second peak on Day 22. All litters of less than 6 pups were born during this later period. The implications of these results in the context of spontaneous labour are discussed. We conclude that endogenous oxytocin (with perhaps other neurohypophysial hormones) released in pulses of 1–3 mu. every 5 min can promote a pattern of labour on Day 21 of gestation that is almost indistinguishable from that which occurs naturally.


2011 ◽  
Vol 70 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Beat Meier ◽  
Anja König ◽  
Samuel Parak ◽  
Katharina Henke

This study investigates the impact of thought suppression over a 1-week interval. In two experiments with 80 university students each, we used the think/no-think paradigm in which participants initially learn a list of word pairs (cue-target associations). Then they were presented with some of the cue words again and should either respond with the target word or avoid thinking about it. In the final test phase, their memory for the initially learned cue-target pairs was tested. In Experiment 1, type of memory test was manipulated (i.e., direct vs. indirect). In Experiment 2, type of no-think instructions was manipulated (i.e., suppress vs. substitute). Overall, our results showed poorer memory for no-think and control items compared to think items across all experiments and conditions. Critically, however, more no-think than control items were remembered after the 1-week interval in the direct, but not in the indirect test (Experiment 1) and with thought suppression, but not thought substitution instructions (Experiment 2). We suggest that during thought suppression a brief reactivation of the learned association may lead to reconsolidation of the memory trace and hence to better retrieval of suppressed than control items in the long term.


1960 ◽  
Vol XXXIII (II) ◽  
pp. 230-250 ◽  
Author(s):  
Eileen E. Hill

ABSTRACT A method for the fractionation of the urinary 17-ketogenic steroids with no oxygen grouping at C11 and those oxygenated at C11, is applied to the clinical problems of congenital adrenal hyperplasia. In normal children the mean ratio of the non-oxygenated to oxygenated steroids is 0.24. In childrern with congenital adrenal hyperplasia the ratio is 2.3. The reason for this difference in ratio is discussed. The changes in ratio found under stimulation of the adrenal gland with exogenous or endogenous corticotrophin and the suppression with cortisone therapy are studied. This test can be applied to isolated samples of urine, a major advantage in paediatric practice, and can be carried out in routine laboratories. It is found to be reliable in the diagnosis and sensitive in the control of congenital adrenal hyperplasia.


Author(s):  
Diana Hart

All countries are faced with the problem of the prevention and control of non-communicable diseases (NCD): implement prevention strategies eff ectively, keep up the momentum with long term benefi ts at the individual and the population level, at the same time tackling hea lth inequalities. Th e aff ordability of therapy and care including innovative therapies is going to be one of the key public health priorities in the years to come. Germany has taken in the prevention and control of NCDs. Germany’s health system has a long history of guaranteeing access to high-quality treatment through universal health care coverage. Th r ough their membership people are entitled to prevention and care services maintaining and restoring their health as well as long term follow-up. Like in many other countries general life expectancy has been increasing steadily in Germany. Currently, the average life expectancy is 83 and 79 years in women and men, respectively. Th e other side of the coin is that population aging is strongly associated with a growing burden of disease from NCDs. Already over 70 percent of all deaths in Germany are caused by four disease entities: cardiovascular disease, cancer, chronic respiratory disease and diabetes. Th ese diseases all share four common risk factors: smoking, alcohol abuse, lack of physical activity and overweight. At the same time, more and more people become long term survivors of disease due to improved therapy and care. Th e German Government and public health decision makers are aware of the need for action and have responded by initiating and implementing a wide spectrum of activities. One instrument by strengthening primary prevention is the Prevention Health Care Act. Its overarching aim is to prevent NCDs before they can manifest themselves by strengthening primary prevention and health promotion in diff erent sett ings. One of the main emphasis of the Prevention Health Care Act is the occupational health promotion at the workplace.


2020 ◽  
Vol 133 (3) ◽  
pp. 830-838 ◽  
Author(s):  
Andrea Franzini ◽  
Giuseppe Messina ◽  
Vincenzo Levi ◽  
Antonio D’Ammando ◽  
Roberto Cordella ◽  
...  

OBJECTIVECentral poststroke neuropathic pain is a debilitating syndrome that is often resistant to medical therapies. Surgical measures include motor cortex stimulation and deep brain stimulation (DBS), which have been used to relieve pain. The aim of this study was to retrospectively assess the safety and long-term efficacy of DBS of the posterior limb of the internal capsule for relieving central poststroke neuropathic pain and associated spasticity affecting the lower limb.METHODSClinical and surgical data were retrospectively collected and analyzed in all patients who had undergone DBS of the posterior limb of the internal capsule to address central poststroke neuropathic pain refractory to conservative measures. In addition, long-term pain intensity and level of satisfaction gained from stimulation were assessed. Pain was evaluated using the visual analog scale (VAS). Information on gait improvement was obtained from medical records, neurological examination, and interview.RESULTSFour patients have undergone the procedure since 2001. No mortality or morbidity related to the surgery was recorded. In three patients, stimulation of the posterior limb of the internal capsule resulted in long-term pain relief; in a fourth patient, the procedure failed to produce any long-lasting positive effect. Two patients obtained a reduction in spasticity and improved motor capability. Before surgery, the mean VAS score was 9 (range 8–10). In the immediate postoperative period and within 1 week after the DBS system had been turned on, the mean VAS score was significantly lower at a mean of 3 (range 0–6). After a mean follow-up of 5.88 years, the mean VAS score was still reduced at 5.5 (range 3–8). The mean percentage of long-term pain reduction was 38.13%.CONCLUSIONSThis series suggests that stimulation of the posterior limb of the internal capsule is safe and effective in treating patients with chronic neuropathic pain affecting the lower limb. The procedure may be a more targeted treatment method than motor cortex stimulation or other neuromodulation techniques in the subset of patients whose pain and spasticity are referred to the lower limbs.


Author(s):  
Maureen L. Whittal ◽  
Melisa Robichaud

The cornerstone of cognitive treatment (CT) for OCD is based upon the knowledge that unwanted intrusions are essentially a universal experience. As such, it is not the presence of the intrusion that is problematic but rather the associated meaning or interpretation. Treatment is flexible, depending upon the nature of the appraisals and beliefs, but can include strategies focused on inflated responsibility and overestimation of threat, importance and control of thoughts, and the need for perfectionism and certainty. The role of concealment and the relationship to personal values are important maintaining and etiological factors. The short-term and long-term treatment outcome is reviewed, along with predictors of treatment response and mechanisms of action, and the chapter concludes with future directions regarding CT for OCD.


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