Brain stimulation technique

Lepore, Marino. 1993. "A Behavioral and Neurological Analysis of the Self-Administration of Brain-Stimulation Technique A Model of Drug Self-Administration." Ph.D. diss., McGill University. 

The most effective surgical technique is deep brain stimulation (DBS) of the STN, which decreases outflow from this region (as shown in Fig. 57-2S) and thus reduces input to the thalamus. STN DBS is especially useful for tremor, dyskinesias, gait disorder, and start hesitation. Thalamic DBS and thalamotomy (a focal destructive lesion of the thalamus) can reduce disabling tremor. Pallidotomy (a focal destructive lesion of the GPi) and GPi DBS can help with severe dyskinesias and on/off fluctuations but is not as helpful for bradykinesia. Destructive lesions are immediate and permanent, whereas DBS requires lifelong maintenance. Transplantation of autologous adrenal medulla tissue was unsuccessful, as has been more recent experience in most cases of fetal tissue transplantation. 

Coughing is a common physiological method to clear the respiratory passages. If it becomes uncontrolled, then medication often can help. Such medications are called antitussives. The cough control center has been located in the medulla of the brain by electrical stimulation techniques. Normally, coughing is caused by chemical or mechanical irritation of the respiratory tract. Therefore, to stop a cough, the source of the respiratory tract irritation should be eliminated and the signal to the medulla interrupted. 

Researchers at the MoneU Center (Philadelphia, Pennsylvania) are using a variety of electrophysical and biochemical techniques to characterize the ionic currents produced in taste and olfactory receptor cells by chemical stimuli. These studies are concerned with the identification and pharmacology of the active ion channels and mode of production. One of the techniques employed by the MoneU researchers is that of "patch clamp." This method aUows for the study of the electrical properties of smaU patches of the ceU membrane. The program at MoneU has determined that odors stimulate intraceUular enzymes to produce cycUc adenosine 3, 5 -monophosphate (cAMP). This production of cAMP promotes opening of the ion channel, aUowing cations to enter and excite the ceU. MoneU s future studies wiU focus on the connection of cAMP, and the production of the electrical response to the brain. The patch clamp technique also may be a method to study the specificity of receptor ceUs to different odors, as weU as the adaptation to prolonged stimulation (3). 

Electrochemical techniques in vivo use the standard three electrode voltammetric system described earlier with the electrodes implanted in the brain of the animal subject. Measurements are made by acquiring some stable baseline signal and then stimulating release of the biogenic amine neurotransmitters. The change in signal is then a measure of the concentration of neurotransmitter in the extracellular fluid. 

In Chapter 43 the incorporation of expertise and experience in data analysis by means of expert systems is described. The knowledge acquisition bottleneck and the brittleness of domain expertise are, however, the major drawbacks in the development of expert systems. This has stimulated research on alternative techniques. Artificial neural networks (ANN) were first developed as a model of the human brain structure. The computerized version turned out to be suitable for performing tasks that are considered to be difficult to solve by classical techniques. 

Since that time, over 35 heterotrimeric G protein subunits have been identified by a combination of biochemical and molecular cloning techniques [1-4]. In addition to G Gs and G , the other types of G protein in brain are designated G0, Golf, G, Gz, Gq and G 16. Moreover, for most of these G proteins, multiple subtypes show unique distributions in the brain and peripheral tissues. G proteins are now divided into four main categories (Table 19-1) the Gs family stimulates adenylyl cyclase the G family (which includes G0, G, Gz) can inhibit... 

Since the early 90s, noninvasive functional brain imaging of humans using NIR methods have been slowly gaining momentum despite existence of more established imaging modailties, such as PET, fMRI, and EEG. Part of the reason as stated previously, is because of its relatively high temporal resolution and its ability to monitor multiple tissue chromophores. The technique has been applied to adult as well as infant studies. NIR method is particularly suited for infant studies as the equipment, at least the CW kind, are minimally restraining, relatively safe, and portable [67]. Most neonatal studies focus on sensory stimulation such as visual, auditory and olfactory stimulations [69] [101] [89] [115] [6] [5], and cerebral disfunction [70, 71]. Our review will focus primarily on adult studies with some emphasis on defense and security applications. 

HT3 receptor agonists have been shown to enhance the release of endogenous dopamine from striatal slices [14] and to reduce acetylcholine release from sections of rat entorhinal cortex [15]. Furthermore, there are several electrophysiological techniques using a variety of neurones, including those in the gut [25] and primary cultures of brain tissue [26] which respond to 5-HT3 agonist stimulation. 

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