The Experts below are selected from a list of 1071 Experts worldwide ranked by ideXlab platform
James E Kehoe - One of the best experts on this subject based on the ideXlab platform.
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magnitude and timing of conditioned responses in delay and trace classical conditioning of the Nictitating Membrane response of the rabbit oryctolagus cuniculus
Behavioral Neuroscience, 2009Co-Authors: James E Kehoe, Elliot Andrew Ludvig, Richard S. SuttonAbstract:The present experiment characterized conditioned Nictitating Membrane (NM) movements as a function of CS duration, using the full range of discernible movements (!.06 mm) rather than movements exceeding a conventional criterion (!.50 mm). The CS–US interval was fixed at 500 ms, while across groups, the duration of the CS was 50 ms (trace), 550 ms (delay), or 1050 ms (extended delay). The delay group showed the highest level of acquisition. When tested with the different CS durations, the delay and extended delay groups showed large reductions in their responses when their CS was shortened to 50 ms, but the trace group maintained its response at all durations. Timing of the conditioned movements appeared similar across all manipulations. The results suggest that the CS has both a fine timing function tied to CS onset and a general predictive function tied to CS duration, both of which may be mediated by cerebellar pathways.
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magnitude and timing of Nictitating Membrane movements during classical conditioning of the rabbit oryctolagus cuniculus
Behavioral Neuroscience, 2008Co-Authors: James E Kehoe, Elliot Andrew Ludvig, Joanne Dudeney, James Neufeld, Richard S. SuttonAbstract:A trial-by-trial, subject-by-subject analysis was conducted to determine whether generation of the conditioned response (CR) occurs on a continuous or all-or-none basis. Three groups of rabbits were trained on different partial reinforcement schedules with the conditioned stimulus presented alone on 10%, 30%, or 50%, respectively, of all trials. Plots of each rabbit's Nictitating Membrane movements revealed that their magnitude rose in a continuous fashion. Response growth during acquisition followed a sigmoidal curve, and the timing of CR-sized movements was largely stable throughout the experiment. The results are discussed with respect to alternative models of CR generation.
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time specific extinction and recovery of the rabbit s oryctolagus cuniculus conditioned Nictitating Membrane response using mixed interstimulus intervals
Behavioral Neuroscience, 2007Co-Authors: Joanne Dudeney, Kirk N. Olsen, James E KehoeAbstract:Extinguishing a conditioned response (CR) has entailed separating the conditioned stimulus (CS) from the unconditioned stimulus (US). This research reveals that elimination of the rabbit Nictitating Membrane response occurred during continuous CS-US pairings. Initial training contained a mixture of 2 CS-US interstimulus intervals (ISIs), 150 ms and 500 ms. The CRs showed double peaks, one for each ISI. When the 150-ms ISI was removed, its CR peak showed 2 hallmarks of extinction: a decline across sessions and spontaneous recovery between sessions. When a further stage of training was introduced with a distinctive CS using the 150-ms ISI, occasional tests of the original, extinguished CS revealed another hallmark of extinction, specifically, strong recovery of the 150-ms peak. These results support both abstract and cerebellar models of conditioning that encode the CS into a cascade of microstimuli, while challenging theories of extinction that rely on changes in CS processing, US representations, and contextual control.
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time and stimulus specificity in extinction of the conditioned Nictitating Membrane response in the rabbit oryctolagus cuniculus
Behavioral Neuroscience, 2007Co-Authors: A Joscelyne, James E KehoeAbstract:The present experiments demonstrated that, in the rabbit Nictitating Membrane preparation, a conditioned response (CR) can be selectively eliminated in one portion of a conditioned stimulus (CS) while it is still paired with the unconditioned stimulus (US). Rabbits were initially trained with two stimuli (tone, light). Each was paired with the US by using a mixture of two CS-US interstimulus intervals (ISIs): 200 ms and 1,200 ms in Experiment 1; 150 ms and 500 ms in Experiment 2. The CRs showed double peaks, one for each ISI. Subsequently, one CS (A) was trained with only the longer ISI, whereas the other CS (B) continued to be trained with both ISIs. Consequently, the CR peak based on the shorter ISI disappeared for CSA but not for CSB. The later CR peaks during both CSA and CSB were maintained. These results support time-based models of conditioning. Implications for proposed mechanisms of extinction are discussed.
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repeated acquisitions and extinctions in classical conditioning of the rabbit Nictitating Membrane response
Learning & Memory, 2006Co-Authors: James E KehoeAbstract:The rabbit Nictitating Membrane (NM) response underwent successive stages of acquisition and extinction training in both delay (Experiment 1) and trace (Experiment 2) classical conditioning. In both cases, successive acquisitions became progressively faster, although the largest, most reliable acceleration occurred between the first and second acquisition. Successive extinctions were similar in rate. The results challenge contextual control theories of extinction but are consistent with attentional and layered-network models. The results are discussed with respect to their implications for the interaction between cerebellar and forebrain pathways for eyeblink conditioning.
Bernard G. Schreurs - One of the best experts on this subject based on the ideXlab platform.
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dietary cholesterol concentration and duration degrade long term memory of classical conditioning of the rabbit s Nictitating Membrane response
International Journal of Alzheimer's Disease, 2012Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Desheng Wang, Lauren B Burhans, Roger W Bell, Jimena GonzalezjoekesAbstract:A rabbit model of Alzheimer's disease based on feeding a cholesterol diet for eight weeks shows sixteen hallmarks of the disease, including learning and memory changes. Although we have shown 2% cholesterol and copper in water can retard learning, other studies show feeding dietary cholesterol before learning can improve acquisition whereas feeding cholesterol after learning can degrade long-term memory. We explored this issue by manipulating cholesterol concentration and duration following classical trace conditioning of the rabbit's Nictitating Membrane response and assessed conditioned responding after eight weeks on cholesterol. First, rabbits given trace classical conditioning followed by 0.5%, 1%, or 2% cholesterol for eight weeks showed body weight and serum cholesterol levels that were a function of dietary cholesterol. Although all concentrations of cholesterol showed some sign of retarding long-term memory, the level of memory retardation was correlated with serum cholesterol levels. Second, rabbits given trace conditioning followed by different durations of a 2% cholesterol diet combined with different durations of a 0% control diet for 8 weeks showed duration and timing of a 2% cholesterol diet were important in affecting recall. The data support the idea that dietary cholesterol may retard long-term memory.
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analysis of long term cognitive enhancing effects of bryostatin 1 on the rabbit oryctolagus cuniculus Nictitating Membrane response
Behavioural Pharmacology, 2008Co-Authors: Desheng Wang, Bernard G. Schreurs, Deya S Darwish, Daniel L AlkonAbstract:Previous work demonstrated that protein kinase C (PKC) is implicated in learning and memory. This study investigated whether: (i) PKC activated by bryostatin-1 (Bryo) just before or just after sessions of classical conditioning was capable of enhancing classical conditioning of the rabbit Nictitating Membrane response; (ii) improved behavioral performance matched the time course of PKC activation induced by Bryo; and (iii) vitamin E (Vit E) enhanced the efficacy of Bryo. Paired rabbits received daily trace conditioning with a tone conditioned stimulus and a corneal air puff unconditioned stimulus. Unpaired rabbits received the same stimuli but in an explicitly unpaired manner. After trace conditioning, all rabbits received daily delay conditioning, and then tone intensity testing. Rabbits pretreated with 10lg/kg Bryo every other day before a relatively simple trace conditioning task showed more conditioned responses (CRs) during the first 10 trials of each trace conditioning session and a higher likelihood of a CR on the first trial of each trace conditioning session than rabbits pretreated with the vehicle control. Rabbits either posttreated daily with 10lg/kg Bryo or pretreated with Vit E and subjected to a difficult trace conditioning task showed increased CRs relative to the vehicle control. Neither Bryo nor Vit E or their combination altered nonassociative responding or altered sensitivity to the conditioned stimulus or unconditioned stimulus. These findings demonstrate Bryo has long-term enhancing effects on classical conditioning of the rabbit Nictitating Membrane response. Behavioural Pharmacology 19:245–256 c 2008 Wolters Kluwer Health | Lippincott Williams & Wilkins. Behavioural Pharmacology 2008, 19:245–256
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high dietary cholesterol facilitates classical conditioning of the rabbit s Nictitating Membrane response
Nutritional Neuroscience, 2007Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Deya S Darwish, Goran Stankovic, Larry D SparksAbstract:Studies have shown that modifying dietary cholesterol may improve learning and that serum cholesterol levels can be positively correlated with cognitive performance. Rabbits fed a 0, 0.5, 1 or 2% cholesterol diet for eight weeks and 0.12 ppm copper added to their drinking water received trace and then delay classical conditioning pairing tone with corneal air puff during which movement of the Nictitating Membrane (NM) across the eye was monitored. We found that the level of classical conditioning and conditioning-specific reflex modification (CRM) as well as the number of beta amyloid-labeled neurons in the cortex and hippocampus were a function of the concentration of cholesterol in the diet. The data provide support for the idea that dietary cholesterol may facilitate learning and memory.
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cholesterol modifies classical conditioning of the rabbit oryctolagus cuniculus Nictitating Membrane response
Behavioral Neuroscience, 2003Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Jeffrey J Lochhead, Larry D SparksAbstract:Cholesterol plays an important role in synapse formation, receptor function, and synaptic plasticity, and animal studies show that modifying cholesterol may improve learning and memory. Other data show that feeding animals cholesterol can induce beta amyloid accumulation. Rabbits (Oryctolagus cuniculus) fed 2% cholesterol for 8 weeks were given trace conditioning of the Nictitating Membrane response using a 100-ms tone, a 700-ms trace, and periorbital electrical stimulation or airpuff. Rabbits fed cholesterol showed significant facilitation of trace conditioning to airpuff and conditioning-specific reflex modification to periorbital electrical stimulation and airpuff. The cholesterol-fed rabbits had beta amyloid accumulation in the cortex, but little in the hippocampus. The data suggest cholesterol had facilitative effects that outweighed potential amnesic effects of cortical beta amyloid.
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conditioning specific reflex modification of the rabbit oryctolagus cuniculus Nictitating Membrane response us intensity effects
Learning & Behavior, 2003Co-Authors: Matthew A Seager, Carrie A Smithbell, Bernard G. SchreursAbstract:Conditioning-specific reflex modification (CRM) of the rabbit’s Nictitating Membrane response (NMR) describes changes in responding to an unconditioned stimulus (US) when the rabbit is tested in the absence of the conditioned stimulus. Specifically, after at least 3 days of tone-electrical stimulation pairings, responses to the US increase in size, especially at intensities weaker than the training intensity. CRM is similar to classical conditioning in that it is a function of the strength of conditioning, it can be extinguished, and it can be generalized from one stimulus to another. To compare CRM and classical conditioning further, we conducted three experiments to examine the effects of US intensity (1.0, 2.0, and 4.0 mA) on CRM. CRM was weak following conditioning with 1.0 mA and extremely strong following conditioning with 2.0 mA and 4.0 mA. The data suggest that CRM is a function of US intensity and have implications for posttraumatic stress disorder, a disorder potentially modeled by CRM.
Richard S. Sutton - One of the best experts on this subject based on the ideXlab platform.
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Timing in trace conditioning of the Nictitating Membrane response of the rabbit (Oryctolagus cuniculus): scalar, nonscalar, and adaptive features.
Learning & memory (Cold Spring Harbor N.Y.), 2010Co-Authors: E. James Kehoe, Elliot Andrew Ludvig, Richard S. SuttonAbstract:Using interstimulus intervals (ISIs) of 125, 250, and 500 msec in trace conditioning of the rabbit Nictitating Membrane response, the offset times and durations of conditioned responses (CRs) were collected along with onset and peak latencies. All measures were proportional to the ISI, but only onset and peak latencies conformed to the criterion for scalar timing. Regarding the CR’s possible protective overlap of the unconditioned stimulus (US), CR duration increased with ISI, while the peak’s alignment with the US declined. Implications for models of timing and CR adaptiveness are discussed.
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magnitude and timing of conditioned responses in delay and trace classical conditioning of the Nictitating Membrane response of the rabbit oryctolagus cuniculus
Behavioral Neuroscience, 2009Co-Authors: James E Kehoe, Elliot Andrew Ludvig, Richard S. SuttonAbstract:The present experiment characterized conditioned Nictitating Membrane (NM) movements as a function of CS duration, using the full range of discernible movements (!.06 mm) rather than movements exceeding a conventional criterion (!.50 mm). The CS–US interval was fixed at 500 ms, while across groups, the duration of the CS was 50 ms (trace), 550 ms (delay), or 1050 ms (extended delay). The delay group showed the highest level of acquisition. When tested with the different CS durations, the delay and extended delay groups showed large reductions in their responses when their CS was shortened to 50 ms, but the trace group maintained its response at all durations. Timing of the conditioned movements appeared similar across all manipulations. The results suggest that the CS has both a fine timing function tied to CS onset and a general predictive function tied to CS duration, both of which may be mediated by cerebellar pathways.
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Scalar timing varies with response magnitude in classical conditioning of the Nictitating Membrane response of the rabbit (Oryctolagus cuniculus).
Behavioral neuroscience, 2009Co-Authors: E. James Kehoe, Kirk N. Olsen, Elliot Andrew Ludvig, Richard S. SuttonAbstract:The present experiment was aimed at characterizing the timing of conditioned Nictitating Membrane (NM) movements as function of the interstimulus interval (ISI) in delay conditioning for rabbits (Oryctolagus cuniculus). Onset latency and peak latency were approximately, but not strictly, scalar for all but the smallest movements ( .50 mm) were less variable, and their peaks were better aligned with the time of US delivery. These results are discussed with respect to their implications for current models of timing in eyeblink conditioning.
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magnitude and timing of Nictitating Membrane movements during classical conditioning of the rabbit oryctolagus cuniculus
Behavioral Neuroscience, 2008Co-Authors: James E Kehoe, Elliot Andrew Ludvig, Joanne Dudeney, James Neufeld, Richard S. SuttonAbstract:A trial-by-trial, subject-by-subject analysis was conducted to determine whether generation of the conditioned response (CR) occurs on a continuous or all-or-none basis. Three groups of rabbits were trained on different partial reinforcement schedules with the conditioned stimulus presented alone on 10%, 30%, or 50%, respectively, of all trials. Plots of each rabbit's Nictitating Membrane movements revealed that their magnitude rose in a continuous fashion. Response growth during acquisition followed a sigmoidal curve, and the timing of CR-sized movements was largely stable throughout the experiment. The results are discussed with respect to alternative models of CR generation.
Carrie A Smithbell - One of the best experts on this subject based on the ideXlab platform.
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dietary cholesterol concentration and duration degrade long term memory of classical conditioning of the rabbit s Nictitating Membrane response
International Journal of Alzheimer's Disease, 2012Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Desheng Wang, Lauren B Burhans, Roger W Bell, Jimena GonzalezjoekesAbstract:A rabbit model of Alzheimer's disease based on feeding a cholesterol diet for eight weeks shows sixteen hallmarks of the disease, including learning and memory changes. Although we have shown 2% cholesterol and copper in water can retard learning, other studies show feeding dietary cholesterol before learning can improve acquisition whereas feeding cholesterol after learning can degrade long-term memory. We explored this issue by manipulating cholesterol concentration and duration following classical trace conditioning of the rabbit's Nictitating Membrane response and assessed conditioned responding after eight weeks on cholesterol. First, rabbits given trace classical conditioning followed by 0.5%, 1%, or 2% cholesterol for eight weeks showed body weight and serum cholesterol levels that were a function of dietary cholesterol. Although all concentrations of cholesterol showed some sign of retarding long-term memory, the level of memory retardation was correlated with serum cholesterol levels. Second, rabbits given trace conditioning followed by different durations of a 2% cholesterol diet combined with different durations of a 0% control diet for 8 weeks showed duration and timing of a 2% cholesterol diet were important in affecting recall. The data support the idea that dietary cholesterol may retard long-term memory.
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high dietary cholesterol facilitates classical conditioning of the rabbit s Nictitating Membrane response
Nutritional Neuroscience, 2007Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Deya S Darwish, Goran Stankovic, Larry D SparksAbstract:Studies have shown that modifying dietary cholesterol may improve learning and that serum cholesterol levels can be positively correlated with cognitive performance. Rabbits fed a 0, 0.5, 1 or 2% cholesterol diet for eight weeks and 0.12 ppm copper added to their drinking water received trace and then delay classical conditioning pairing tone with corneal air puff during which movement of the Nictitating Membrane (NM) across the eye was monitored. We found that the level of classical conditioning and conditioning-specific reflex modification (CRM) as well as the number of beta amyloid-labeled neurons in the cortex and hippocampus were a function of the concentration of cholesterol in the diet. The data provide support for the idea that dietary cholesterol may facilitate learning and memory.
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cholesterol modifies classical conditioning of the rabbit oryctolagus cuniculus Nictitating Membrane response
Behavioral Neuroscience, 2003Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Jeffrey J Lochhead, Larry D SparksAbstract:Cholesterol plays an important role in synapse formation, receptor function, and synaptic plasticity, and animal studies show that modifying cholesterol may improve learning and memory. Other data show that feeding animals cholesterol can induce beta amyloid accumulation. Rabbits (Oryctolagus cuniculus) fed 2% cholesterol for 8 weeks were given trace conditioning of the Nictitating Membrane response using a 100-ms tone, a 700-ms trace, and periorbital electrical stimulation or airpuff. Rabbits fed cholesterol showed significant facilitation of trace conditioning to airpuff and conditioning-specific reflex modification to periorbital electrical stimulation and airpuff. The cholesterol-fed rabbits had beta amyloid accumulation in the cortex, but little in the hippocampus. The data suggest cholesterol had facilitative effects that outweighed potential amnesic effects of cortical beta amyloid.
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conditioning specific reflex modification of the rabbit oryctolagus cuniculus Nictitating Membrane response us intensity effects
Learning & Behavior, 2003Co-Authors: Matthew A Seager, Carrie A Smithbell, Bernard G. SchreursAbstract:Conditioning-specific reflex modification (CRM) of the rabbit’s Nictitating Membrane response (NMR) describes changes in responding to an unconditioned stimulus (US) when the rabbit is tested in the absence of the conditioned stimulus. Specifically, after at least 3 days of tone-electrical stimulation pairings, responses to the US increase in size, especially at intensities weaker than the training intensity. CRM is similar to classical conditioning in that it is a function of the strength of conditioning, it can be extinguished, and it can be generalized from one stimulus to another. To compare CRM and classical conditioning further, we conducted three experiments to examine the effects of US intensity (1.0, 2.0, and 4.0 mA) on CRM. CRM was weak following conditioning with 1.0 mA and extremely strong following conditioning with 2.0 mA and 4.0 mA. The data suggest that CRM is a function of US intensity and have implications for posttraumatic stress disorder, a disorder potentially modeled by CRM.
Larry D Sparks - One of the best experts on this subject based on the ideXlab platform.
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high dietary cholesterol facilitates classical conditioning of the rabbit s Nictitating Membrane response
Nutritional Neuroscience, 2007Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Deya S Darwish, Goran Stankovic, Larry D SparksAbstract:Studies have shown that modifying dietary cholesterol may improve learning and that serum cholesterol levels can be positively correlated with cognitive performance. Rabbits fed a 0, 0.5, 1 or 2% cholesterol diet for eight weeks and 0.12 ppm copper added to their drinking water received trace and then delay classical conditioning pairing tone with corneal air puff during which movement of the Nictitating Membrane (NM) across the eye was monitored. We found that the level of classical conditioning and conditioning-specific reflex modification (CRM) as well as the number of beta amyloid-labeled neurons in the cortex and hippocampus were a function of the concentration of cholesterol in the diet. The data provide support for the idea that dietary cholesterol may facilitate learning and memory.
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cholesterol modifies classical conditioning of the rabbit oryctolagus cuniculus Nictitating Membrane response
Behavioral Neuroscience, 2003Co-Authors: Bernard G. Schreurs, Carrie A Smithbell, Jeffrey J Lochhead, Larry D SparksAbstract:Cholesterol plays an important role in synapse formation, receptor function, and synaptic plasticity, and animal studies show that modifying cholesterol may improve learning and memory. Other data show that feeding animals cholesterol can induce beta amyloid accumulation. Rabbits (Oryctolagus cuniculus) fed 2% cholesterol for 8 weeks were given trace conditioning of the Nictitating Membrane response using a 100-ms tone, a 700-ms trace, and periorbital electrical stimulation or airpuff. Rabbits fed cholesterol showed significant facilitation of trace conditioning to airpuff and conditioning-specific reflex modification to periorbital electrical stimulation and airpuff. The cholesterol-fed rabbits had beta amyloid accumulation in the cortex, but little in the hippocampus. The data suggest cholesterol had facilitative effects that outweighed potential amnesic effects of cortical beta amyloid.