Biological Psychology and Drug Treatment - Essay Example

? Biological psychology Response to Question Part a. The means and standard deviations of the Racropride binding for the eight participants before and after rTMS which denotes the concentration of dopamine is the independent variable while the two structures i.e. the caudate nucleus and the putamen are the dependent variables. This implies plotting the type of structure against the means and standard deviations of the Racropride binding for the eight participants. Part b. The study design is the within participant study. This is because the same eight participants were used in each group. In this case, the eight participants were used in the before and after the repetitive Transcranial Magnetic Stimulation, as well as in the four listed structures (R caudate nucleus, L caudate nucleus, R putamen and L putamen. Part c. The study failed to take into consideration the daily sessions of rTMS, for each patient, which would be vital in indicating the motor threshold per session. The study only talks about the number of PET scan each patient underwent two. Statistically, it would have been vital to indicate the Stimulus intensity. It was also statistically important that the scan order be randomized among the ten participants and all the scans be conducted at the same time. However, this was not told about the study. Part d. From the data presented, the neuropsychological tests for all the eight individuals were high above seven. This implies that before the repetitive Transcranial Magnetic Stimulation (rTMS), all the eight patients had depression with two pairs of the patients having the same level of depression. However, after each patient undergoing Repetitive Transcranial Magnetic Stimulation treatment, there were noted variations in their responses to the rTMS. Three of the patients were no longer depressed after undergoing repetitive Transcranial Magnetic Stimulation (rTMS) while the remaining five were still under depression. One patient of the five witnessed an increase in his level of depression while the remaining four witnessed a slight drop in their depression levels. On the overall, considering their means and SD before and after the repetitive Transcranial magnetic Stimulation, there was a significant drop in their depression levels down from 17.4 plus or minus 2.6 to 10.4 plus or minus 6.0. This follows after the use of rTMS. This study, therefore, implies that repetitive Transcranial Magnetic Stimulation can be effective in treating depression (Ramony, S. 2008). Hence from the results above, it is true that repetitive Transcranial Magnetic Stimulation is capable of eliciting moderate antidepressant effects as claimed in several studies. Part e. Analysis of the results reveals that there is a significant increase in the caudate nuclei but a significant reduction in putamen for both left and right hemispheres. In light of data presented in the table above, the PET scans were used in quantifying the effect of left and right rTMS on the prefrontal dopamine with the main objectives of identifying dopaminergic changes in the ipsilateral prefrontal cortex. The raclopride and PET scan were used in measuring changes in dopamine concentration following the repetitive TMS of the eight subjects. There was increase in the means and standard deviations in right Caudate nucleus from 2.72 plus or minus 0.35 to 2.85 plus or minus 0.31. There was an increase in the means and standard deviations in the Left Caudate nucleus from 2.76 plus or minus 0.30 to 2.78 plus or minus 0.25. In the right putamen, the means and standard deviation dropped significantly from 3.46 plus or minus 0.44 to 3.40 plus or minus 0.31 while the left putamen witnessed a significant decrease in the means and the standard deviation dropping from 3.52 plus or minus 0.32 to 3.47 plus or minus 0.28. in changes in binding in the right putamen. On the overall, there was a significant increase in the levels of functional dopamine receptors in the Caudate nucleus and a significant drop in the putamen. The changes in both cases are compensational in terms of their means and SD since, whereas there seems to be low Raclopride binding prior to using rTMS for the Caudate nuclei with increase after the rTMS, this is compensated with a reduction in Raclopride binding for the case of Putamen. It is observed that there are significant changes in Raclopride. This, therefore, suggests that there is a measurable increase in the release of dopamine. This implies, therefore, that there is evident to suggest that rTMS has some effect on the dopamine system. Response to Question 2 Perhaps the accuracy of synaptic connections of the nervous system is the most remarkable feature for the nervous system. The circuit networks so formed by neuronal interactions aid in the generation of behaviors. Synapse formations are finely regulated involving processes at the sub cellular and cellular levels. This result in axons finding their targets from the many choices with the synapses formed on the correct cellular compartment alongside the formation of pre- and postsynaptic specialization which allows for efficient information transfer. This study discuses various mechanism used by the nervous system in guiding axonal growth, as well as how these mechanisms are used in determining the survival of the neurons. After the formation of a new cell or a neuroblast, the new cell differentiates into its adult form that has a particular function. In completing this function to enable it share information, as well as connect with other cells, it develops an axon. However, the projected axon has to find the right destination. The projections that come at the beginning stage are referred to as neutrites whose tip contains a growth cone. The growth cone located at the tip of the neutrite is specialized to finding the proper destination with the use of the probe-like structures. At the end of this neutrite, there is a lamellipodia which has flat pieces of cell membrane that extends forming a knob. A filapodia which is a tiny finger-like extension extends from the lamellipodia. While the lamellipodia extends exploring new environments, the filopodia probes in and out of the lamellipodia while pulling back and forth. The growth of the axon takes place when the filapodia attaches itself to support and pulls the lamellipodia forward. The support upon which this is attached to is called the extracellular matrix. The extracellular matrix is one of the structures of the brain found outside the neurons and is made up of glial cells. Additionally, cell adhesion molecule is sticky and allows the filopodia to get attached to allow the axon to grow together. The growth cone has small signals and is guided by cues within the environment. Chemo-attractant makes the growth cones to grow towards them with chemo-repellants turning the growth cones away. The growth cones contain special receptors that help in detecting the chemical cues. The synapses are formed from growth cones when they come in contact with the target. When growth cone reaches the target, chemicals it secrets signals the post-synaptic receptor formation. Certain proteins would interact between the target and the growth cone thereby binding them together. Ions such as Calcium are exchanging, which promote the neurotransmitter releasing from the growth cone when forming a pre-synaptic terminal. Changes in genes expression, as well takes place. This enables the making of new proteins for synaptic structures and receptors. The outgrowth of axons during the process of neuronal development, along with regeneration after the injury of the adult nervous system is often under the control of specific extracellular cues that are bound or diffusible to the cell membrane. The exact molecular mechanism through which the extracellular signals are all integrated by the growing axon, are not well defined. It is, however, widely accepted that most signaling cascades that are triggered by guidance cues converge the cytoskeleton. In essence, the action of the extracellular guidance factors is modulated by the cytoskeletal, specific receptors, as well as the cytoskeleton-associated molecules inside the axon. In this case, the cytoskeleton represents a point of integration and of convergence of the extrinsic and the neuron-intrinsic factors. How the mechanisms are used in determining the survival of the neurons. At the junction of the neuromuscular, synapses often compete for innervations of the muscle fiber. Even though the competition results into decrease in the number of synaptic that are inputs to the muscle, the synaptic input complexity increases with the strengths of each synapse, as well increasing. Some synapses get eliminated during development. The synapse elimination along the neuromuscular junction involves the withdrawal of the pre-synaptic terminal and a loss of AChEs. The activity-dependent competition occurring at the motor axons tend to favor the more active input. The direct competition existing between the nerve fibers always favors the axons that can compete for trophic factors that are provided by the target cell. The indirect competition enables the muscle to be able to select the axon most favored. In the adult, all the muscle fibers are always innervated by one motor neuron. In the early development most of the postsynaptic targets get innervated by many nerve terminals especially for the skeletal muscles. During the synapse maturation most terminals tend to disappear. The elimination of synapse is occurs by the pre-synaptic terminals withdrawal. Even though it is thought that the number of distinct synaptic inputs decreases for any given target during the process, Complexities of the individual terminals that are remaining actually increases. These mechanisms are vital for the development of the nervous system because of a number of reasons. For instance, in the development of the cerebellum, granule cells migrate long distances in the processes of radial glial cells. The migration starts from the external granule layer ending up at the granule cell layer (Ramony, S. 2008). For instance, the epithelial cells located at the neural tube luminal surface proliferate giving rise to neuroblasts The neuroblasts develops into the radial glial cells while extending their processes from luminal to pial surfaces. The granule neurons that occur during the development of the cerebellum, migrates to the molecular layer through the processes of radial glial cells. The key discoveries in this field has been the ability of growing axons to be able to navigate through a more complex cellular embryonic terrain in finding the appropriate synaptic partners that can be centimeters or millimeters away. Cellular mechanisms underlying these complex searching movements have increasingly become a major focus of cell biological studies concerning the axon growth and guidance. The experiment carried out by Purves Danson, and Augustine Justine have shown that such movements reflect, and controll the arrangements of the cytoskeleton elements especially the molecules that are related to the actin cytoskeleton. These molecules modulate the changes in the shape of the growth cone and it is said to be the course through the developing tissues. From this study it is imperative to make the following conclusions. First, repetitive Transcranial Magnetic Stimulation can be effective in treating depression and it is capable of eliciting moderate antidepressant effects. Secondly, there is evidence to suggest that rTMS has some effect on the dopamine system. Thirdly, there are various mechanism used by the nervous system in guiding axonal growth and these mechanisms are also used in determining the survival of the neurons. However, more research needs to be conducted in cellular mechanisms to find the principles that underlie these complex searching movements. Response to question 3. Experiment (C-Fos) comparing A amphetamine and S saline. Abstract. Drugs treatments and different types of experiences have the ability to change the spines and neuronal dendrites morphology in the regions of brain. We hypothesized that, a drug like amphetamine might have a more effect to the brain region than a saline environment. This hypothesis was tested by having rats treated continuously with amphetamine and saline and then having them housed in complex environments. First, the rats went through an amphetamine repeated treatment then followed by a saline treatment. Secondly, the rats were put into an environment that was complex for about three minutes. The brain of the rats was processed for quantified dendrites branching and density of spine on neurons in the cerebral part of the brain. It was reported that experience saline and amphetamine had a limitation in the ability of experience in complex environment by altering the morphology of dendrites. It was concluded that in brain, repeated exposure to drug treatments limits the ability of experience that could lead to cognitive or behavioral deficits that are linked to drugs. Introduction. Experiences that depend on behavior come about because of altering the neurons physical structures. Research has shown that this is the central tenet of neuropsychological theory. Studies on experience- dependent changes within the regions of brain compared the housing of animals in a complex relative environment and standard cage laboratories (Ramony, S. 2008). This study reported an increased dendrite length of cells in the neocortical mantle in the complex environments and could give out changes in synaptic connectivity pattern. Ability of experiences to change structures of dendrites is of great importance and is believed to be the basic mechanism through which past experiences affects subsequent behavior. Dendrites structure alterations are also linked to pathological states. Particularly, studies have shown repeated treatment using psycho-stimulant drugs like amphetamine to give out a lasting increase in spine density and dendrite branching of the regions of brain. The fact that drug abuse and environmental manipulations like salinity have a similar effect on morphology neurons brings our questions on the degree to which these two types of experiences may compare and interact (Ramony, S. 2008). In attempt to answer these questions, a study is designed to investigate the comparison of amphetamine and saline effects to the regions of brain. In this regard, we hypothesized that amphetamine might have a more effect to the brain region than a saline environment. Method. The participants of this study were 27 female Sprague-Dawley rats. These subjects weighed 150 to 250 g during the experiment. The animals housed in a hanging cage room. They were divided into four groups according to the treatment condition. The first group was a group of rats treated with saline and housed in standard cage laboratory (n=5). The second group was one with rats that were given a saline treatment and housed in environments that are complex (n= 7). The third group consisted of rats that were given an amphetamine treatment and obtained standard cage laboratory housing (n= 6). The last group contained rats that were given an amphetamine treatment and housed in complex environment (n=9). The resources that were needed for this study include slides, i.p injection, amphetamine sulphate, saline, and a cell counter device. The rats were treated with 0.70mg/kg d-amphetamine sulphate. They were then given nine injections of 1mg/kg saline. After two days, the brains of the rats were obtained and cell count in the selected brain region (CP) determined. This experiment was repeated for all the slide numbers and the cell count for each treatment recorded in a table (Table1). Results. The results obtained were recorded in table 1. Table 1: A comparison of A (amphetamine) and S (saline). Treatment Rat number Brain region Slide number Cell count A 1 CP 1 67 A 1 CP 2 17 A 1 CP 3 27 A 1 CP 4 31 A 1 CP 5 67 A 1 CP 6 85 A 2 CP 1 70 A 2 CP 2 26 A 2 CP 3 67,89 A 2 CP 4 56,68 A 2 CP 5 18 A 2 CP 6 20 A 3 CP 1 31 A 3 CP 2 27 A 3 CP 3 28 A 2 CP 4 57 A 3 CP 5 28 A 3 CP 6 19 S 1 CP 1 2,6,2,10,2,3 S 1 CP 2 1 S 1 CP 3 2 S 2 CP 1 1 S 2 CP 2 2,1,2,2,2,1,5 S 2 CP 3 2 S 3 CP 1 0 S 3 CP 2 0 S 3 CP 3 0,1,0,0,0,0 Data analysis. The mean cell count for the amphetamine treatment is Mean = = = 43 The mean for the saline treatment is Mean = = 1 The mean for amphetamine treatment is higher than that of saline treatment. The standard deviation of saline treatment is Standard deviation = = 1.73 The standard deviation for the amphetamine treatment is = = 5.675. The p value for this study was 0.029. Discussion of the results. The experience in the amphetamine treatment increased the number of cell count compared to those of saline treatment. This was so because the amphetamine treatment increased the spine density to the level which appeared to be below that of the cells found in the saline treatment (Ramony, S. 2008). The interaction of experience in complex environments and amphetamine treatment gave out substantial evidence that exposure to amphetamine could prevent or even block the effects of experience subsequently. From the data, treatment with amphetamine appeared to tamper with the experience ability in an environment that was complex. In this case, it increased the spine density and dendritic branching in the cells resulting to increased cell count. For saline experience, there were no incremental effects over and above the counts recorded in the amphetamine treatment. However, the effect of amphetamine could be possibly due to an already maximum count, and that further morphological plasticity failed to be possible. The molecular and cellular mechanisms that are responsible in neuro-adaptations do occur in a consequence of experiences that have a number of similarities to those which occur due to exposure consequences to abuse of drugs. Research has shown that drug abuse interfere with the normal mechanisms that are responsible for experience-dependent plasticity including changes in the synaptic connectivity patterns. In this case, synaptic organization that is produced by drugs like the amphetamine interacts with those given out due to experience like saline. This study showed out a sensitive way for studying synaptic plasticity, which is linked to a complex environment, long-term potential, gonadal manipulation, learning, cortical injury, and drug treatment. From the study, the hypothesis of this study was, therefore, approved. Conclusion. This research reported that, the exposure to drug influences the experience in an environment that is complex so that it can shape the structure of dendrites in the neocortical brain region. This meditates functions of sensory-motor, and the number of dendrites spines in the brain. Measures of an amphetamine or saline treatment interfered with the chances of experiences hence increasing the arborization of the dendrites and the count of dentritic-spines in the brain. The results for this study proved that repeated exposure to drug treatments limits the ability of experience that could lead to cognitive or behavioral deficits that are linked to drugs. References Ramony, S., 2008. Biology psychology. London: Oxford University Press. Read More