Deep Brain Stimulation
Electrical stimulation of the brain is an important therapy for refractory neurological disorders such as drug resistant Parkinson's disease and severe tremor and has become an area of active clinical research in both neurology and psychiatry. Using a technique called deep brain stimulation (DBS), small electrical leads are placed into the brain using stereotactic localization. A special head frame is attached to the skull under local anesthesia, and electrodes are implanted using internal brain targets located with reference to anatomical landmarks determined by brain imaging techniques such as computed tomography (CT) or magnetic resonance imaging (MRI). This technique allows for the precise targeting of specific brain sites or nuclei. Insertion of electrodes can be done without damage to adjacent tissue. These electrodes are connected by a wire to a pacemaker implanted in the chest that generates electrical stimulation. Stimulation parameters can be modified by manipulation of the...
Ryoichi Nakano, Department of Neurology, Brain Research Institute, Niigata University. His group revealed that the granular cytoplasmic aggregates were formed accompanied by collapse of the cytoplasm in cells expressing mutant SODs, but not in cells expressing wild-type SODs 16,17 .
On chemical reactions in individual visual cells. It would not be appropriate to assume that the timing of the output impulses is the same in all of the visual cells. In other words, it is very likely that at a given moment when you observe the straight line of Figure 4, the impulse data being input into your brain is almost random information. This state of affairs has continued from your birth to the present moment. It means, if we think naturally, we can conclude that human beings never receive symbolic information.
You suspect you have endometriosis, or your doctor may have diagnosed you with the disease. However, you're wondering how the endometriosis you have in your pelvic area can end up in your lungs or even your brain. It didn't catch the red-eye from your uterus to your lungs, so how does endometriosis travel to different areas in your body from the pelvic area
Several therapeutic modalities have been proposed for the treatment of patients in persistent vegetative state. Sensory and electrical stimulation is a method that attempts to increase arousal'' in vegetative patients. Deep brain stimulation of the mesencephalic reticular formation increases cerebral evoked potentials and EEG activity, whereas cervical cord spinal stimulation can activate cerebral glucose metabolism and blood flow. Pharmacological manipulation of the central nervous system has also been attempted in several cases of persistent vegetative state. Treatment with amantadine or Sinemet has been reported to improve the level of consciousness in some patients. However, these reports are anecdotal, and prospective, controlled trials with significant numbers of patients are required to determine the true efficacy of these treatment protocols. Nutrition should also be considered a component of the therapeutic regiment. The degree of nutritional support should correlate with the...
The biggest challenge to the dream theory that dreams have psychological meaning and are the fulfillment of unconscious wishes came from the brain researchers and neuroanatomists written in 1977 by J. Allan Hobson and Robert W. McCarley. Since the discovery of REM nearly 50 years ago, many brain researchers feel that Freud's theory of dreams is no longer in tune with the laboratory findings on sleep physiology. They play down past psychological traumas as psychological meaning in favor of memory consolidation and feel that dreams are mental nonsense, have no psychological references, and should not be taken seriously. Thus, the biological conception of dreams is at odds with the psychological, with a tendency to neglect the nonbiological explanation. Whatever the position taken, as Michael Gazzaniga points out in the 1990s in his split-brain research, the human brain inherently seeks to make sense of all stimuli, including dreams, through the work of what he calls the interpreter. The...
If you want to try medication without counseling first, your doctor may suggest one of the many antidepressants available. Most of these medications change the balance of the nerve chemicals in your brain. These chemical messengers, called neurotransmitters, are released by nerves and then taken up again by the nerves for reuse.
The finding of separable storage and retrieval mnemonic deficits restricted in the temporal domain in PD was followed up by a new set of experiments asking whether distinct neural pathways underlie those deficits. To this end, we applied the same encode-decode design in a series of studies testing PD patients OFF levodopa undergoing deep brain stimulation (DBS) either in the subthalamic nucleus (STn) or the pallidum. The effect of DBS is reversible, and the stimulation parameters (principally site and voltage) can be varied to achieve the optimal therapeutic result (Benabid et al., 1991, 1998). Moreover, the reversibility of DBS means that patients' cognitive performance can be assessed both with (ON) and without (OFF) DBS. This in turn presents the possibility of identifying specific patterns of impairment, including cognitive ones, associated with the stimulated basal ganglia substructures.
Analyzing the human brain transcriptome and interpreting the outcome of these experiments is a challenging task. Although many of the following considerations are not unique for genomic experiments and apply in general to postmortem brain research, they have a major impact on planning and interpreting the outcome of microarray experiments. Indeed, sample integrity remains one of the most critical aspects in postmortem brain research. In concordance with previous literature reports (Harrison et al., 1995), we found little evidence that samples with shorter PMIs would be more suitable for microarray analysis than those with longer PMIs. Rather, RNA integrity appears to be more dependent on the circumstances ofdeath. Currently, the best surrogate measurement of agonal state and RNA integrity appears to be brain pH values. In general, samples with pH values less than 6.25 have a high probability of containing significant amounts of degraded RNA, thereby preventing a high-quality...
Formed closely to a predicted line of perfect matching where response ratios are matched to ratios of obtained reinforcements. The matching law is defined as the matching of response ratios to reinforcement ratios where the match is most robust when dealing with concurrent variable interval variable interval and concurrent variable interval variable ratio reinforcement schedules of operant behavior. Experiments using pigeons, rats, and people as participants show that the matching law applies when they choose between alternative sources of food, brain stimulation, and information, respectively. The three species, doing different things for different consequences, all crowd the theoretical matching line. The acknowledged qualifications on the matching law involve three empirical issues the equivalence of responses, the equivalence of rewards, and the interactions among drives. Much is unsettled about matching as a general principle, but various quantitative conclusions can be drawn...
Age and other factors in motor recovery from precentral lesions in monkeys. American Journal of Physiology, 115, 138-146. Kennard, M. A. (1940). Relation of age to motor impairment in man and subhuman primates. Archives of Neurology and Psychiatry, 44, 377-397. Schneider, G. E. (1979). Is it really better to have your brain lesion early A revision of the Kennard principle. Neuropsychology, 17, 557-583. Finger, S., & Wolf, C. (1988). The Kennard effect before Kennard The early history of age and brain lesions. Archives of Neurology, 45, 1136-1142. Webb, C., Rose, F., Johnson, D., & Attree, E.
A) Tom (aged 8 years) undergoes transcranial magnetic brain stimulation while his mother looks on. The coil is held against his head over the area of the cortical representation of his left hand. (Photograph used with child and parental consent.) B) An example of a motor evoked potential recorded from the first dorsal interosseous (index finger) muscle. The latency corresponds to the total motor conduction time. Figure 1. A) Tom (aged 8 years) undergoes transcranial magnetic brain stimulation while his mother looks on. The coil is held against his head over the area of the cortical representation of his left hand. (Photograph used with child and parental consent.) B) An example of a motor evoked potential recorded from the first dorsal interosseous (index finger) muscle. The latency corresponds to the total motor conduction time.
Deep brain stimulation raises special concerns because neuromodulation techniques deal with the direct stimulation of the brain. No other organ is so closely involved with concepts of mind or self, self-determination and consent. THERAPEUTIC VERSUS INVESTIGATIONAL USE. Given the rapid development of this field, it is important to determine whether the application of deep brain stimulation Today, the use of a device such as the deep brain stimulator goes through several investigational stages before it is accepted as therapeutic. Formal mechanisms are in place to codify this transition. The FDA uses the investigational device exemption process to regulate devices that pose significant risk, such as the deep brain stimulator (Pritchard, Abel, and Karanian). FDA procedures, which supplement institutional review board (IRB) oversight of clinical trials, are designed to establish the safety and efficacy of devices and are required by law.
Research in deep brain stimulation is blurring the disciplinary boundaries between neurology and psychiatry. French investigators have discovered that DBS caused transient acute depression in a patient with Parkinson's disease whose motor function had improved markedly through DBS intervention (Bejjani et al.). Investigators are conducting clinical trials for the use of DBS for severe psychiatric illnesses such as obsessive compulsive disorder using techniques pioneered in the treatment of movement disorders (Roth et al. Rapoport and Inoff-Germain). Nicholas D. Schiff and colleagues have proposed the use of DBS for the modulation of consciousness after severe traumatic brain injury (Schiff, Plum, and Rezai).
Your doctor will draw your blood and check your prolactin level before you begin treatment with Parlodel. If your prolactin level is elevated, you will probably undergo a magnetic resonance imaging (MRI) of your head. The purpose of that radiological study is to evaluate your brain's pituitary gland. Once you begin Parlodel, your doctor will order blood work to evaluate your response to the medication.
Tagliati M, Alterman RL, Shils JL, Miravite J, Bressman SB. Progressive improvement of generalized dystonia after pallidal deep brain stimulation. Neurology 2003 60(suppl 1) A344. Yianni J, Bain PG, Gregory RP, Nandi D, Joint C, Scott RB, et al. Postoperative progress of dystonia patients following globus pallidus internus deep brain stimulation. Eur J Neurol 2003 10 239-247.
The whole human situation is extremely complex, compounded by intricate interactions between nutrition, environment, and heredity on the overall development of physical and mental health. The brain stands in the center of this complex milieu, and, as noted by John Eccles, a great pioneer in brain research, we must continue to use our brains to understand how they show plasticity toward these and other possible
Singer I'm trying to take a neuroscientific perspective on your research on empathy and fit your data into this account. The easy neuroscientific story would be to suggest that the better your action perception resonance mechanism in your brain, the more you share the feelings of others and the more empathic you are. This would imply, however, that sharing negative emotions with others lead automatically to own distress. Now you are showing negative correlations between personal distress and helping behaviour, the latter again associated with empathy. According to such a view, any resonance mechanism resulting in personal distress by the sight of someone suffering negative emotions is hindering empathy.
The dosage of Clomid varies but usually ranges from 50 mg to 200 mg daily. Most women start with a daily dosage of 50 mg, and if ovulation does not occur, the dose will be increased. Take your Clomid tablets at approximately the same time each day. Because Clomid works by interrupting your normal hormonal messages and feedback between your brain and ovaries, you should time your Clomid hormonal messages just right.
Have you ever been envious of people who seem to have no end of clever ideas, who are able to think quickly in any situation, or who seem to have flawless memories? Could it be that they're just born smarter or quicker than the rest of us? Or are there some secrets that they might know that we don't?