The Experts below are selected from a list of 25365 Experts worldwide ranked by ideXlab platform
David M Diamond - One of the best experts on this subject based on the ideXlab platform.
-
two day radial arm Water Maze learning and memory task robust resolution of amyloid related memory deficits in transgenic mice
Nature Protocols, 2006Co-Authors: Jennifer Alamed, Marcia N Gordon, Donna M Wilcock, David M Diamond, Dave MorganAbstract:Two-day radial-arm Water Maze learning and memory task; robust resolution of amyloid-related memory deficits in transgenic mice
-
Two-day radial-arm Water Maze learning and memory task; robust resolution of amyloid-related memory deficits in transgenic mice
Nature Protocols, 2006Co-Authors: Jennifer Alamed, Marcia N Gordon, Donna M Wilcock, David M Diamond, Dave MorganAbstract:The radial arm Water Maze (RAWM) contains six swim paths (arms) extending out of an open central area, with an escape platform located at the end of one arm (the goal arm). The goal arm location remains constant for a given mouse. On day 1, mice are trained for 15 trials (spaced over 3 h), with trials alternating between visible and hidden platform. On day 2, mice are trained for 15 trials with the hidden platform. Entry into an incorrect arm is scored as an error. The RAWM has the spatial complexity and performance measurement simplicity of the dry radial arm Maze combined with the rapid learning and strong motivation observed in the Morris Water Maze without requiring foot shock or food deprivation as motivating factors. With two sessions each day, 16 mice can be tested over 2 days.
-
exposing rats to a predator impairs spatial working memory in the radial arm Water Maze
Hippocampus, 1999Co-Authors: David M Diamond, Collin R Park, Karen L Heman, Gregory M RoseAbstract:This series of studies investigated the effects of predator exposure on working memory in rats trained on the radial arm Water Maze (RAWM). The RAWM is a modified Morris Water Maze that contains four or six swim paths (arms) radiating out of an open central area, with a hidden platform located at the end of one of the arms. The hidden platform was located in the same arm on each trial within a day and was in a different arm across days. Each day rats learned the location of the hidden platform during acquisition trials, and then the rats were removed from the Maze for a 30-min delay period. During the delay period, the rats were placed either in their home cage (nonstress condition) or in close proximity to a cat (stress condition). At the end of the delay period, the rats were run on a retention trial, which tested their ability to remember which arm contained the platform that day. The first experiment confirmed that the RAWM is a hippocampal-dependent task. Rats with hippocampal damage were impaired at learning the location of the hidden platform in the easiest RAWM under control (non-stress) conditions. The next three experiments showed that stress had no effect on memory in the easiest RAWM, but stress did impair memory in more difficult versions of the RAWM. These findings indicate that the capacity for stress to impair memory is influenced not only by the brain memory system involved in solving the task (hippocampal versus nonhippocampal), but also by the difficulty of the task. This work should help to resolve some of the confusion in the literature regarding the heterogeneous effects of stress on hippocampal-dependent learning and memory. Hippocampus 1999;9:542–552. © 1999 Wiley-Liss, Inc.
Dave Morgan - One of the best experts on this subject based on the ideXlab platform.
-
two day radial arm Water Maze learning and memory task robust resolution of amyloid related memory deficits in transgenic mice
Nature Protocols, 2006Co-Authors: Jennifer Alamed, Marcia N Gordon, Donna M Wilcock, David M Diamond, Dave MorganAbstract:Two-day radial-arm Water Maze learning and memory task; robust resolution of amyloid-related memory deficits in transgenic mice
-
Two-day radial-arm Water Maze learning and memory task; robust resolution of amyloid-related memory deficits in transgenic mice
Nature Protocols, 2006Co-Authors: Jennifer Alamed, Marcia N Gordon, Donna M Wilcock, David M Diamond, Dave MorganAbstract:The radial arm Water Maze (RAWM) contains six swim paths (arms) extending out of an open central area, with an escape platform located at the end of one arm (the goal arm). The goal arm location remains constant for a given mouse. On day 1, mice are trained for 15 trials (spaced over 3 h), with trials alternating between visible and hidden platform. On day 2, mice are trained for 15 trials with the hidden platform. Entry into an incorrect arm is scored as an error. The RAWM has the spatial complexity and performance measurement simplicity of the dry radial arm Maze combined with the rapid learning and strong motivation observed in the Morris Water Maze without requiring foot shock or food deprivation as motivating factors. With two sessions each day, 16 mice can be tested over 2 days.
Joseph P Huston - One of the best experts on this subject based on the ideXlab platform.
-
Research Histidine-Decarboxylase Knockout Mice Show Deficient Nonreinforced Episodic Object Memory, Improved Negatively Reinforced Water-Maze Performance, and Increased Neo- and Ventro-Striatal Dopamine Turnover
2016Co-Authors: Ekrem Dere, Helmut L. Haas, Bianca Topic, Richard E Spieler, Maria A De Souza Silva, Joseph P HustonAbstract:The brain’s histaminergic system has been implicated in hippocampal synaptic plasticity, learning, and memory, as well as brain reward and reinforcement. Our past pharmacological and lesion studies indicated that the brain’s histamine system exerts inhibitory effects on the brain’s reinforcement respective reward system reciprocal to mesolimbic dopamine systems, thereby modulating learning and memory performance. Given the close functional relationship between brain reinforcement and memory processes, the total disruption of brain histamine synthesis via genetic disruption of its synthesizing enzyme, histidine decarboxylase (HDC), in the mouse might have differential effects on learning dependent on the task-inherent reinforcement contingencies. Here, we investigated the effects of an HDC gene disruption in the mouse in a nonreinforced object exploration task and a negatively reinforced Water-Maze task as well as on neo- and ventro-striatal dopamine systems known to be involved in brain reward and reinforcement. Histidine decarboxylase knockout (HDC-KO) mice had higher dihydrophenylacetic acid concentrations and a higher dihydrophenylacetic acid/dopamine ratio in the neostriatum. In the ventral striatum, dihydrophenylacetic acid/dopamine and 3-methoxytyramine/dopamine ratios were higher in HDC-KO mice. Furthermore, the HDC-KO mice showed improved Water-Maze performance during both hidden and cued platform tasks, but deficient object discrimination based on temporal relationships. Our data imply that disruption of brain histamine synthesis can have both memory promoting and suppressive effects via distinct and independen
-
behavior on the Water Maze platform relationship to learning and open field exploration in aged and adult rats
Brain Research Bulletin, 2007Co-Authors: Daniela Schulz, Chariklia Kouri, Joseph P HustonAbstract:In the present study we examined whether age-related deficits in the Water Maze could be accounted for by changes in the behavior on the platform, and whether platform behavior represents some form of exploration, akin to that seen in the open field. Twenty-seven aged and 8 adult rats (26 and 3 months old Wistar rats, respectively) were tested in an empty open field and spatial object exploration task, followed by 9 days of escape learning in a Water Maze. The aged as compared to the adults exhibited lower levels of open field activity and were deficient in the object displacement task. Escape deficits in the Water Maze and reduced activity levels on the platform were also found. In the aged, Water Maze performance was correlated with behavior on the platform, including quiescence, orienting-like activity and turning behavior, a form of axial rotation. In both age groups, turning behavior was also correlated with exploratory activity in the open field. In conclusion, the results support the hypothesis that age-related impairments in the Water Maze relate to changes in platform behavior, which, in turn, might reflect exploratory activity.
-
aged and adult rats compared in acquisition and extinction of escape from the Water Maze focus on individual differences
Behavioral Neuroscience, 2005Co-Authors: B Topic, Ekrem Dere, Daniela Schulz, Maria A De Souza Silva, Gerhard Jocham, Emriye Kart, Joseph P HustonAbstract:Individual differences in Water Maze and open-field performance of aged and adult rats were compared in a cross-sectional study. Three- and 24-month-old rats were classified into superior, moderate, and inferior groups on the basis of escape latencies during hidden platform acquisition and were compared regarding Water Maze acquisition and extinction, and open-field behavior. Unexpectedly, subgroup differences were invariant across age: The inferior and superior Maze learners differed in (a) thigmotactic swimming during Water Maze acquisition and extinction and (b) open-field rearings. Thus, although aging has a detrimental effect on Water Maze acquisition and extinction, the degree of impairment might be partly determined by individual novelty-induced rearing activity and thigmotactic swimming at adult ages.
-
histidine decarboxylase knockout mice show deficient nonreinforced episodic object memory improved negatively reinforced Water Maze performance and increased neo and ventro striatal dopamine turnover
Learning & Memory, 2003Co-Authors: Ekrem Dere, Helmut L. Haas, Maria A De Souzasilva, Bianca Topic, Richard E Spieler, Joseph P HustonAbstract:The brain's histaminergic system has been implicated in hippocampal synaptic plasticity, learning, and memory, as well as brain reward and reinforcement. Our past pharmacological and lesion studies indicated that the brain's histamine system exerts inhibitory effects on the brain's reinforcement respective reward system reciprocal to mesolimbic dopamine systems, thereby modulating learning and memory performance. Given the close functional relationship between brain reinforcement and memory processes, the total disruption of brain histamine synthesis via genetic disruption of its synthesizing enzyme, histidine decarboxylase (HDC), in the mouse might have differential effects on learning dependent on the task-inherent reinforcement contingencies. Here, we investigated the effects of an HDC gene disruption in the mouse in a nonreinforced object exploration task and a negatively reinforced Water-Maze task as well as on neo- and ventro-striatal dopamine systems known to be involved in brain reward and reinforcement. Histidine decarboxylase knockout (HDC-KO) mice had higher dihydrophenylacetic acid concentrations and a higher dihydrophenylacetic acid/dopamine ratio in the neostriatum. In the ventral striatum, dihydrophenylacetic acid/dopamine and 3-methoxytyramine/dopamine ratios were higher in HDC-KO mice. Furthermore, the HDC-KO mice showed improved Water-Maze performance during both hidden and cued platform tasks, but deficient object discrimination based on temporal relationships. Our data imply that disruption of brain histamine synthesis can have both memory promoting and suppressive effects via distinct and independent mechanisms and further indicate that these opposed effects are related to the task-inherent reinforcement contingencies.
Jennifer Alamed - One of the best experts on this subject based on the ideXlab platform.
-
two day radial arm Water Maze learning and memory task robust resolution of amyloid related memory deficits in transgenic mice
Nature Protocols, 2006Co-Authors: Jennifer Alamed, Marcia N Gordon, Donna M Wilcock, David M Diamond, Dave MorganAbstract:Two-day radial-arm Water Maze learning and memory task; robust resolution of amyloid-related memory deficits in transgenic mice
-
Two-day radial-arm Water Maze learning and memory task; robust resolution of amyloid-related memory deficits in transgenic mice
Nature Protocols, 2006Co-Authors: Jennifer Alamed, Marcia N Gordon, Donna M Wilcock, David M Diamond, Dave MorganAbstract:The radial arm Water Maze (RAWM) contains six swim paths (arms) extending out of an open central area, with an escape platform located at the end of one arm (the goal arm). The goal arm location remains constant for a given mouse. On day 1, mice are trained for 15 trials (spaced over 3 h), with trials alternating between visible and hidden platform. On day 2, mice are trained for 15 trials with the hidden platform. Entry into an incorrect arm is scored as an error. The RAWM has the spatial complexity and performance measurement simplicity of the dry radial arm Maze combined with the rapid learning and strong motivation observed in the Morris Water Maze without requiring foot shock or food deprivation as motivating factors. With two sessions each day, 16 mice can be tested over 2 days.
Michael T Williams - One of the best experts on this subject based on the ideXlab platform.
-
dopamine depletion in either the dorsomedial or dorsolateral striatum impairs egocentric cincinnati Water Maze performance while sparing allocentric morris Water Maze learning
Neurobiology of Learning and Memory, 2015Co-Authors: Amanda A Braun, Charles V Vorhees, Robyn M Amoskroohs, Arnold Gutierrez, Kerstin H Lundgren, Kim B Seroogy, Matthew R Skelton, Michael T WilliamsAbstract:Both egocentric route-based learning and spatial learning, as assessed by the Cincinnati Water Maze (CWM) and Morris Water Maze (MWM), respectively, are impaired following an 80% dopamine (DA) loss in the neostriatum after 6-hydroxydopamine (6-OHDA) administration in rats. The dorsolateral striatum (DLS) and the dorsomedial striatum (DMS) are implicated in different navigational learning types, namely the DLS is implicated in egocentric learning while the DMS is implicated in spatial learning. This experiment tested whether selective DA loss through 6-OHDA lesions in the DMS or DLS would impair one or both types of navigation. Both DLS and DMS DA loss significantly impaired route-based CWM learning, without affecting spatial or cued MWM performance. DLS 6-OHDA lesions produced a 75% DA loss in this region, with no changes in other monoamine levels in the DLS or DMS. DMS 6-OHDA lesions produced a 62% DA loss in this region, without affecting other monoamine levels in the DMS or DLS. The results indicate a role for DA in DLS and DMS regions in route-based egocentric but not spatial learning and memory. Spatial learning deficits may require more pervasive monoamine reductions within each region before deficits are exhibited. This is the first study to implicate DLS and DMS DA in route-based egocentric navigation.
-
developmental treatment with the dopamine d2 3 agonist quinpirole selectively impairs spatial learning in the morris Water Maze
Neurotoxicology and Teratology, 2009Co-Authors: Charles V Vorhees, Holly L Johnson, Lindsey N Burns, Michael T WilliamsAbstract:Developmental exposure to the dopamine D2/3 receptor agonist quinpirole is reported to induce D2 priming, impair Morris Water Maze performance, reduce acoustic startle prepulse inhibition (PPI), and alter locomotor activity. We treated rats from postnatal days 1-21 with the dose reported to induce these effects, 1.0 mg/kg/day, and two higher doses, 2.0 and 4.0 mg/kg/day, or saline. Offspring were tested in the Morris Water Maze, PPI, exploratory locomotor activity, activity after quinpirole and (+)-methamphetamine challenge, elevated zero Maze, light-dark box, marble burying, straight channel swimming, and Cincinnati Water Maze. In the Morris Water Maze, all quinpirole groups had longer latencies on test days 3-5 of acquisition, but no effects on reversal or shifted-reduced platform trials. The quinpirole 4.0 mg/kg group had significantly reduced mean search distances on probe trials when combined across the 3 phases of testing but not separately. The male 4.0 mg/kg quinpirole group showed a greater increase in methamphetamine-stimulated activity during the first 10 min after drug challenge but not in the remainder of the 2 h test. No quinpirole effects were found for light-dark box, marble burying, exploratory locomotor activity, straight channel, Cincinnati Water Maze, or locomotor activity after quinpirole challenge. No effects were found on most measures in the elevated zero Maze however the quinpirole 4.0 mg/kg females had longer latencies to enter an open quadrant. The results partially support prior Morris Maze deficits induced by developmental quinpirole treatment but little evidence of dopamine D2/3 priming was found using locomotor activity with quinpirole or methamphetamine challenge or acoustic startle/PPI. The limited comparability to published data using developmental quinpirole exposure may be attributable to differences in experimental procedures or may be the result of quinpirole having limited effects. The data suggest that caution is warranted concerning the developmental efficacy of quinpirole.
-
Morris Water Maze: procedures for assessing spatial and related forms of learning and memory
Nature Protocols, 2006Co-Authors: Charles V Vorhees, Michael T WilliamsAbstract:The Morris Water Maze (MWM) is a test of spatial learning for rodents that relies on distal cues to navigate from start locations around the perimeter of an open swimming arena to locate a submerged escape platform. Spatial learning is assessed across repeated trials and reference memory is determined by preference for the platform area when the platform is absent. Reversal and shift trials enhance the detection of spatial impairments. Trial-dependent, latent and discrimination learning can be assessed using modifications of the basic protocol. Search-to-platform area determines the degree of reliance on spatial versus non-spatial strategies. Cued trials determine whether performance factors that are unrelated to place learning are present. Escape from Water is relatively immune from activity or body mass differences, making it ideal for many experimental models. The MWM has proven to be a robust and reliable test that is strongly correlated with hippocampal synaptic plasticity and NMDA receptor function. We present protocols for performing variants of the MWM test, from which results can be obtained from individual animals in as few as 6 days.
