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User:Maddierawding/sandbox

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Basic Definition

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The Morris Water Maze Navigation Task (MWM) is one of the most widely used tests in behavioral neuroscience. [1] Researchers have found the maze to be an accurate study of learning, memory, and spatial working memory and use it to assess the effect of damage to cortical regions of the brain on both rats and mice.[2] [3] It is used largely by neuroscientists to measure the effect of neurocognitive disorders on spatial learning and possible neural treatments, to test the effect of lesions to the brain in areas focused on memory, and to study how age influences cognitive function and spatial learning. [4] [5] In order to study certain neurocognitive disorders, scientists use gene-targeting on mice and inactivate a specific gene which results in behavioral changes similar to those that result from diseases like Alzheimer’s. [6] The MWM is also used as a tool to study learning in transgenic mice, the effect of drug-abuse, neural systems, neurotransmitters, and brain development. [7] [8]

History

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The Morris Water Maze was invented by Richard G. Morris in 1981 as an alternative to the radial arm maze. [9] The test was made to study spatial learning and how it varied from other forms of associative learning. [10] Originally rats, now more commonly mice, were placed in an open pool and the latency to escape was measured for up to six trials a day for 2-14 days.[11] Now, procedures are varied. A "probe" trial measures how long the test subject spends in the "target" quadrant (the quadrant with the hidden platfform of the pool when the exit is removed. [12] More elaborate trials alter the location of the hidden exit and measure distance spent swimming in the pool before reaching the platform. [13] Neuroscientists examine many different variables in the test including the effects of differences in sex, weight, strength, stress levels, age, and strain of species. The results differ dramatically, so researchers cannot make conclusions about a wide range of tests unless the manipulations are relatively minor. [14] Although the original dimensions were explicitly outlined, many different size mazes have been used throughout the history of this task. Studies show however, that varying the diameter of the pool does not have a significant impact on the results of the test. [15] Some people refer to it as a maze while others refer to it as a task that provides an open field for learning. [16] In early versions of the MWM researchers only timed latency to escape, however now video tracking devices can measure the path to escape, time spent in each quadrant, and distance traveled in the pool. [17]

Comparison to other mazes

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The Morris Water Maze is preferred to a lot of other spatial tasks because it measures spatial memory, movement control, and cognitive mapping whereas other mazes only measure one of these three tasks. The T-maze and radial arm maze are much more structured in comparison. [18] The T-maze, for instance, only requires the rat or mouse to make a bilateral decision, choose left or right. In the MWM, on the other hand, the animal is continually deciding where to go. [19] Another reason this task became popular is that rats and mice are natural swimmers so in order to perform the task they do not need to be motivated by food deprivation or electrical shock. [20] The platform is mobile which allows for tests on learning and relearning. The expereiment is still effective when animals are admministered multiple doses of drugs. [21] As opposed to dry tasks, the MWM takes a relatively short time allowing researchers to perform more tests efficiently. [22] Also, the apparatus set-up and costs are relatively low as compared to other mazes. [23]

Insights for neuroscience

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Spatial learning

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The MWM is a very simple task, and for that reason, very effective in measuring spatial learning. The opaque water prevents the rat from using visual, auditory, and olfactory cues and therefore eliminates possible uncontrolled variables. The primary brain regions involved in this type of learning are the hippocampus, striatum, basal forebrain cholinergic system, cerebellum and several neocortical areas. [24] MWM experiments on rats and mice with altered brain regions helped to define the role each region has in spatial memory. Rats and mice with hippocampal lesions for example, can move through the maze properly, but they are not able to navigate and thus fail to create cognitive maps. [25] [26] The cognitive map is made up of place cells in the hippocampus that record information about the location in respect to cues in the environment (allocentric space) rather than getting sensory stimulus from the location (egocentric space) allowing for the animal to record spatial information find the hidden platform in the MWM. [27]

The striatum, located in the basal ganglia, also plays a role in spatial movement. Rats with lesions in the striatum were placed in the MWM to explore the relationship between visuospatial skills, cognitive flexibility, and recall.[28] The experiment showed that rats with lesions in the medial striatum had difficulty with all three tasks in the MWM with a hidden platform however, had no difficulty navigating to a visible platform indicating that the striatum also plays a role in moving in allocentric space. [29] Right next to the striatum is the basal forebrain, another area that when altered affects MWM performance. Tasks have been performed on mice with adjusted levels of acetylcholine in the Cholinergic System to show the role of the basal forebrain in spatial learning. Altering the neurochemistry of rats has shown that two neurotransmitters play a major role in spatial learning; both acetylcholine and glutamate.[30]

See Also

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Spatial memory

Radial arm maze Place Cells T-Maze


My Wikipedia Page Hippocampus

  1. ^ d'Hooge, R.; De Deyn, P. P. (2001 Aug). "Applications of the Morris water maze in the study of learning and memory". Brain Research. Brain Research Reviews. 36 (1): 60–90. doi:10.1016/s0165-0173(01)00067-4. PMID 11516773. S2CID 2651456. {{cite journal}}: Check date values in: |date= (help)
  2. ^ Morris, RG (1982 Jun 24). "Place navigation impaired in rats with hippocampal lesions". Nature. 297 (5868): 681–3. doi:10.1038/297681a0. PMID 7088155. S2CID 4242147. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  3. ^ d'Hooge, R.; De Deyn, P. P. (2001 Aug). "Applications of the Morris water maze in the study of learning and memory". Brain Research. Brain Research Reviews. 36 (1): 60–90. doi:10.1016/s0165-0173(01)00067-4. PMID 11516773. S2CID 2651456. {{cite journal}}: Check date values in: |date= (help)
  4. ^ d'Hooge, R.; De Deyn, P. P. (2001 Aug). "Applications of the Morris water maze in the study of learning and memory". Brain Research. Brain Research Reviews. 36 (1): 60–90. doi:10.1016/s0165-0173(01)00067-4. PMID 11516773. S2CID 2651456. {{cite journal}}: Check date values in: |date= (help)
  5. ^ Sharma, S (2010 Oct 23). "Assessment of spatial memory in mice". Life Sciences. 87 (17–18): 521–36. doi:10.1016/j.lfs.2010.09.004. PMC 6457258. PMID 20837032. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  6. ^ Ledda, F.; Marchetti, P.; Mugelli, A. (1975 May). "Studies on the positive inotropic effect of phenylephrine: a comparison with isoprenaline". British Journal of Pharmacology. 54 (1): 83–90. doi:10.1111/j.1476-5381.1975.tb07413.x. PMC 1666381. PMID 1139077. {{cite journal}}: Check date values in: |date= (help)
  7. ^ Wongwitdecha, N (1996 Apr 9). "Effects of social isolation rearing on learning in the Morris water maze". Brain Research. 715 (1–2): 119–24. doi:10.1016/0006-8993(95)01578-7. PMID 8739630. S2CID 12321749. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  8. ^ Mendez, IA (2008 Feb). "Long-term effects of prior cocaine exposure on Morris water maze performance". Neurobiology of Learning and Memory. 89 (2): 185–91. doi:10.1016/j.nlm.2007.08.005. PMC 2258220. PMID 17904876. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  9. ^ Wenk, GL (2004 May). "Assessment of spatial memory using the radial arm maze and Morris water maze". Current protocols in neuroscience / editorial board, Jacqueline N. Crawley ... [et al.] Chapter 8: Unit 8.5A. PMID 18428607. {{cite journal}}: Check date values in: |date= (help)
  10. ^ Morris, R (1984 May). "Developments of a water-maze procedure for studying spatial learning in the rat". Journal of Neuroscience Methods. 11 (1): 47–60. doi:10.1016/0165-0270(84)90007-4. PMID 6471907. S2CID 8292701. {{cite journal}}: Check date values in: |date= (help)
  11. ^ Morgan, D (2009). "Water Maze Tasks in Mice: Special Reference to Alzheimer's Transgenic Mice". PMID 21204327. {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  12. ^ Morgan, D (2009). "Water Maze Tasks in Mice: Special Reference to Alzheimer's Transgenic Mice". PMID 21204327. {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  13. ^ Morgan, D (2009). "Water Maze Tasks in Mice: Special Reference to Alzheimer's Transgenic Mice". PMID 21204327. {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  14. ^ d'Hooge, R.; De Deyn, P. P. (2001 Aug). "Applications of the Morris water maze in the study of learning and memory". Brain Research. Brain Research Reviews. 36 (1): 60–90. doi:10.1016/s0165-0173(01)00067-4. PMID 11516773. S2CID 2651456. {{cite journal}}: Check date values in: |date= (help)
  15. ^ Van Dam, D (2006 Mar). "Effect of Morris water maze diameter on visual-spatial learning in different mouse strains". Neurobiology of Learning and Memory. 85 (2): 164–72. doi:10.1016/j.nlm.2005.09.006. PMID 16290194. S2CID 19824659. {{cite journal}}: Check date values in: |date= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  16. ^ Foreman, Nigel (1998). Handbook of Spatial Research and Paridigms and Methodologies: Clinical and Comparitive Studies Volumee 2. United Kingdom: Psychology Press. p. 145. ISBN 9780863778070.
  17. ^ Buccafusco, J. J.; Terry Jr, A. V. (2009). "Spatial Navigation (Water Maze) Tasks". PMID 21204326. {{cite journal}}: Cite journal requires |journal= (help)
  18. ^ Hodges, H (1996 Jun). "Maze procedures: the radial-arm and water maze compared". Brain Research. Cognitive Brain Research. 3 (3–4): 167–81. doi:10.1016/0926-6410(96)00004-3. PMID 8806020. {{cite journal}}: Check date values in: |date= (help)
  19. ^ Morris, R (1984 May). "Developments of a water-maze procedure for studying spatial learning in the rat". Journal of Neuroscience Methods. 11 (1): 47–60. doi:10.1016/0165-0270(84)90007-4. PMID 6471907. S2CID 8292701. {{cite journal}}: Check date values in: |date= (help)
  20. ^ Morris, R (1984 May). "Developments of a water-maze procedure for studying spatial learning in the rat". Journal of Neuroscience Methods. 11 (1): 47–60. doi:10.1016/0165-0270(84)90007-4. PMID 6471907. S2CID 8292701. {{cite journal}}: Check date values in: |date= (help)
  21. ^ Buccafusco, J. J.; Terry Jr, A. V. (2009). "Spatial Navigation (Water Maze) Tasks". PMID 21204326. {{cite journal}}: Cite journal requires |journal= (help)
  22. ^ Morgan, D (2009). "Water Maze Tasks in Mice: Special Reference to Alzheimer's Transgenic Mice". PMID 21204327. {{cite journal}}: Cite journal requires |journal= (help); Unknown parameter |coauthors= ignored (|author= suggested) (help)
  23. ^ Buccafusco, J. J.; Terry Jr, A. V. (2009). "Spatial Navigation (Water Maze) Tasks". PMID 21204326. {{cite journal}}: Cite journal requires |journal= (help)
  24. ^ d'Hooge, R.; De Deyn, P. P. (2001 Aug). "Applications of the Morris water maze in the study of learning and memory". Brain Research. Brain Research Reviews. 36 (1): 60–90. doi:10.1016/s0165-0173(01)00067-4. PMID 11516773. S2CID 2651456. {{cite journal}}: Check date values in: |date= (help)
  25. ^ Morris, R. G.; Garrud, P.; Rawlins, J. N.; O'Keefe, J. (1982 Jun 24). "Place navigation impaired in rats with hippocampal lesions". Nature. 297 (5868): 681–3. doi:10.1038/297681a0. PMID 7088155. S2CID 4242147. {{cite journal}}: Check date values in: |date= (help)
  26. ^ Best, P. J.; White, A. M.; Minai, A. (2001). "Spatial processing in the brain: the activity of hippocampal place cells". Annual Review of Neuroscience. 24: 460. doi:10.1146/annurev.neuro.24.1.459. PMID 11283318. {{cite journal}}: More than one of |pages= and |page= specified (help)
  27. ^ Best, P. J.; White, A. M.; Minai, A. (2001). "Spatial processing in the brain: the activity of hippocampal place cells". Annual Review of Neuroscience. 24: 463. doi:10.1146/annurev.neuro.24.1.459. PMID 11283318. {{cite journal}}: More than one of |pages= and |page= specified (help)
  28. ^ Furtado, J. C.; Mazurek, M. F. (1996 Mar). "Behavioral characterization of quinolinate-induced lesions of the medial striatum: relevance for Huntington's disease". Experimental Neurology. 138 (1): 158–68. doi:10.1006/exnr.1996.0054. PMID 8593891. S2CID 23139490. {{cite journal}}: Check date values in: |date= (help)
  29. ^ Furtado, J. C.; Mazurek, M. F. (1996 Mar). "Behavioral characterization of quinolinate-induced lesions of the medial striatum: relevance for Huntington's disease". Experimental Neurology. 138 (1): 158–68. doi:10.1006/exnr.1996.0054. PMID 8593891. S2CID 23139490. {{cite journal}}: Check date values in: |date= (help)
  30. ^ McNamara, R. K.; Skelton, R. W. (1993 Jan-Apr). "The neuropharmacological and neurochemical basis of place learning in the Morris water maze". Brain Research. Brain Research Reviews. 18 (1): 33–49. doi:10.1016/0165-0173(93)90006-l. PMID 8467349. S2CID 21588247. {{cite journal}}: Check date values in: |date= (help)
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