The Influence of Lithium Chloride on Rats Exploratory Behavior - Assignment Example

The Influence of Lithium Chloride on Rat’s Exploratory Behavior in an Open Field Apparatus Mehrdad Ghorayshi Department of Neuroscience, of Texas at Dallas ABSTRACT The effects of Lithium chloride (LiCl) on Sprague Dawley male rats were assessed to examine how LiCl versus a control solution Sodium Chloride (NaCl) changed the innate fear and exploratory behavior of these rats. This experiment was accomplished in an open field apparatus, which is an enclosed box measuring 4 inches by 4 inches. The movement of the rats within the apparatus and the time a rat spent at the center of the apparatus served as measures of determining the rat’s exploratory behavior after the injection of LiCl. The obtained results from observing and recording the number of times a rat entered the center of the field (i.e. the center 4 tiles), the amount of time a rat spent in the center of the field (i.e. the center 4 tiles), and the number of tile crossings all indicated that rats treated with LiCl had indeed reduced risk taking, locomotor activity and exploratory behavior when undergoing the open-field test compared to sodium chloride (NaCl) treated control rats. Note, the tendency of the rat to cling and spend much time on the walls of the test apparatus indicates a high level of anxiety or fear. On the contrary, a less fearful rat portrays the tendency of greater exploration within the experiment apparatus. As such, the rats that had been injected with LiCl spent much time on the walls of the apparatus – a sign of increased fear and high level of anxiety. The results obtained in this test were in agreement with other studies previously conducted. INTRODUCTION Laboratory observations have suggested an interaction between lithium chloride (LiCl) and exploratory behavior of rats. Studies have confirmed that LiCl administration tends to suppress locomotor activity in rats (Johnson et al., 1972). An open field apparatus was used to observe the exploratory behavior and the movement of the rats one hour after the injection of LiCl. The purpose of the present study was to examine the effects of LiCl on risk taking, exploratory behavior, and locomotor activity of rats. The behavioral pharmacology test conducted was aimed at seeing the effectiveness of Lithium chloride on the various specimens used and their response. The experiment used Lithium Chloride as the main ingredient and sodium chloride as the control solution. The main objective of the experiment was an observation of the effects of taking against not taking Lithium chloride and on the other hand taking sodium chloride. We used an Open Field Apparatus from whence we could observe the behavior of the rat immediately after the injection with the drug. Hypothetically, the compound normally modifies the exploratory behavior, innate fears, and locomotive behaviors of rats and mice. The experiment was carried out to observe the truthfulness and effectiveness of the above mentioned objectives. Locomotor activity was measured by monitoring the total number of times rats crossed the tile lines, number of times rats entered the center of the field and the amount of time the rats spent in the center of the open field apparatus for ten minutes one hour after the injection of LiCl. The purpose of this study was to examine the effects of LiCl on rats to address the hypothesis of whether LiCl has any modifying effects on rat’s exploratory and risk-taking behavior as well as its locomotor activity. Researches indicate that LiCl causes significant decreases in the locomotor activity and exploratory behavior of rats (Smith, 1983). METHODS AND MATERIALS Subject This experiment was examined under specific setup and procedures at room temperature. 20 Sprague Dawley male rats weighing between 250 g and 350 g were treated with 1% LiCl (85mgs/kg) or NaCl intraperitoneally (I.P) exactly one hour before the open field experiment was performed. The rats were housed in pairs in polypropylene cages with food and water provided. At the time of the experiment, they were handled into the open field box by scooping one hand under their belly and were placed into a corner of the apparatus gently. Set up An open field apparatus was used to observe the effects of LiCl on the locomotor activity of these rats. The open field apparatus is an enclosed box of size 4’x4’ (each tile is 1’x1’). The apparatus has an open top with four sides made out of 4’x 2’x1’ wood pieces. This setup required an experimenter to place the rat in a corner of the box. The apparatus was placed in a dark and a quiet room where the experiment was examined. Procedure Rats treated with LiCl and NaCl were placed in the open field apparatus separately for ten minutes and their activity was monitored by three people each measuring various parameters that were recorded. These parameters are as follows. The number of times that the rat entered the center of the field (that is; the center 4 tiles). The duration of time that the rat spent in the center of the field (that is; the center four tiles). The number of times that the rat crossed the floor tile line (number of crossings). . Data Analysis An unpaired t-test was used to compare groups. P values < .05 were considered significant. Error bars = SEM. RESULTS In a study of 20 Sprague Dawley male rats that had been injected with LiCl, they exhibited reduced exploratory behavior when undergoing the open-field test. They spent most of the time along the walls of the apparatus. The administration with LiCl brought noticeable reduction in the amount of movement and the intensity of the movement in the rats. The speed of the rats as they moved from one area to another tended to get lower as they got further cautious of their surroundings. The rats that were injected with NaCl did not have the mentioned changes as they had normal movement and most of them moved randomly covering almost all corners of the apparatus. Rats treated with LiCl exhibited significant suppressed locomotor activity compared to control rats during the recording for all activity variables including time in the center [ Avg=13.4618 (sec) , t-score= 2.2961, P-value=0.0326 ] whereas rats treated with NaCl showed more amount of time spent in the center [Avg= 24.4045 (sec)] as seen in Fig (1). The number of crossings into the center in rats injected LiCl and NaCl were compared and this comparision indicates that animals treated with LiCl showed less number of crossings into the center than controls [Avg=4.2727 (sec), t-score=3.1811, P-value=0.0046] Fig(2). In the last measurement, rats treated with LiCl had less total line crossings compared to rats treated with saline. [Avg=75, t-score=4.6947, P-value=0.0002] Fig (3). In general, this analysis revealed that rats treated with LiCl displayed reduced risk taking, exploratory behavior and locomotor activity. (A study confirmed that LiCl causes significant decreases in the locomotor activity of rats (Smith, 1983). Fig 1. A comparison of the Average Time in center(sec) between the two compounds. Fig. 2. A comparison of the average crossings into center between the two compounds Fig. 3 A comparison of the average total line crossings between the two compounds DISCUSSION The observed outcome of our experiment indicates that our results are in concurrence with our hypothesis. LiCl suppressed the exploratory and risk taking behavior of rats significantly as they spent longer time in the corner and less time in the center of the open field apparatus during the experiment compared to rats treated with Saline; In addition, the results of total line crossings and number of times rats crossed into the center are also in support of our hypothesis. The theoretical background of the experiment comes to be in agreement with the results and the general discussion of other studies as well. Concisely, intrinsic fears in rats, which were given LiCl, rose such that they stayed along the walls of the box away from the center (Andre, et al., 2007). However, One study supports that rats treated with LiCl exhibited freezing behavior and shaking of the forepaws. This outcome can address the rise to the innate fear and stress of rats during this experiment. Therefore, we can conclude that reduced risk taking and exploratory behavior of rats can be due to the fact that LiCl induced stress in rats and diminished their locomotor activity and tendency to explore the center area of the box. However, in contrast to our results, one study found that the locomotor activity of rats has been increased after three weeks of LiCl treatment with normal intake of water. Future studies should, therefore, approach various experimental settings such as effects of LiCl on isolated vs. group-housed rats and prolonged treatment of rats with LiCl to fully assess the influence of this compound on exploratory behavior of rats. CONCLUSION Lithium chloride is an important compound in the treatment of bipolar disorder. In rats, the compound kicks up the fears in them making them a little bit more apprehensive compared to others that had not been injected with the same compound (Godwin & Gary). As observed, Lithium chloride reduces the patters of exploration in the rats, impairs the time they take to try and go back to doing something after a distraction, as well as, making them fear going to open spaces. The increase in fear and apprehensiveness can be what happens in humans when injected with Lithium. The increase in levels of fears tends to cause people who are overly daring due to bipolar disease tone down in some of the antics (John 479). On the other hand, as observed, it tends to bring about calm in people with overly active behaviors. The tests can be termed as a confirmation of the so many tests done on rats ever since people realized that lithium has an effect on the minds of animals and humans; and more so, humans with bipolar disorders. Thus, the hypothesis of the experiment comes to be in agreement with the results of the experiment and the general discussion. Concisely, intrinsic fears in rats rose such that they stayed along the walls of the box (Andre, et al. 125). In addition, the daring nature of some rats was maintained by administering them with Sodium Chloride. We can do this experiment in larger open field box to see if small box has anything to do with their locomotor activity! Work Cited Andre, Justin St., Katie Albanos, and Steve Reilly. "C-fos Expression in the Rat Brain following Lithium Chloride-induced Illness." Brain Research (2007): 122-28. Print. Goodwin, Guy, and Gary Sachs. Bipolar Disorder. 2nd ed. Abingdon: HEALTH, 2010. Print. John, Frederick “Effects of Alpha Methyltyrosine and Parachlorophenylalanine on Open Field Behavior in Rats given Tranylcypromine Stereoisomers and Lithium Carbonate." Pharmacology Biochemistry and Behavior (2011): 479. Print. Kiesbye, Stefan. Bipolar Disorder. Farmington Hills, MI: Greenhaven/Gale Cengage Learning, 2010. Print. Mackenzie, West. "Lithium: Agent of Choice in Bipolar Disorder." Inpharma Weekly (2010): 2. Print. Quinn, Brian. Bipolar Disorder. Hoboken, N.J.: John Wiley & Sons, 2007. Print. Sproule, Beth. "Lithium in Bipolar Disorder." Clinical Pharmacokinetics (2009): 639-60. Print. Sterner, Ray T. "Plasma Lithium as a Marker of Lithium Chloride in Wild Norway Rats (R. Norvegicus)." Physiology & Behavior (2010): 1013-015. Print. Young, A. H. "Lithium in Maintenance Therapy for Bipolar Disorder." Journal of Psychopharmacology (2006): 17-22. Print Read More