Mindfulness and psychoeducation to manage stress in amnestic mild cognitive impairment: A pilot study.

Amnestic mild cognitive impairment (aMCI) often corresponds to the prodromal stage of Alzheimer disease (AD). The aMCI stage represents a crucial time window to apply preventive interventions in an attempt to delay cognitive decline. Stress, one of AD's modifiable risk factors frequently co-occurring with aMCI, stands out as a key intervention target.

Potential benefits of mindfulness-based interventions in mild cognitive impairment and Alzheimer's disease: an interdisciplinary perspective.

The present article is based on the premise that the risk of developing Alzheimer's disease (AD) from its prodromal phase (mild cognitive impairment; MCI) is higher when adverse factors (e.g., stress, depression, and metabolic syndrome) are present and accumulate.

Contribution of the dorsal subiculum to memory for temporal order and novelty detection using objects, odors, or spatial locations in the rat.

The contribution of the dorsal subiculum (DS) to memory for temporal order and novelty detection was assessed using a spontaneous exploration paradigm with objects (visual/tactile stimuli), odors, or spatial locations (Hunsaker, Fieldsted, Rosenberg, & Kesner, 2008). Rats with selective excitotoxic lesions of the DS were compared to sham-operated rats (SHAM) in the two exploration tests. In temporal order tests, two previously explored stimuli were presented and normal rats typically show a preference for exploring the stimulus that was first explored compared to the other stimulus.

Additional evidence for intact appetitive trace conditioning in hippocampal-lesioned rats.

Hippocampal lesions impair aversive trace conditioning but do not interfere with appetitive Pavlovian trace conditioning of the licking response (LR). This experiment examined whether learning to discriminate the events occurring in the home cage and in the training chamber could account for the differential effects of hippocampal lesions on aversive and appetitive trace conditioning. Performance of rats with excitotoxic lesions of the hippocampus was compared to that of sham-operated rats in LR trace conditioning.

Impaired social motivation and increased aggression in rats subchronically exposed to phencyclidine.

Phencyclidine (PCP) treatment induces social withdrawal in the rat model of schizophrenia but little is known about the qualitative adequacy of behaviors displayed during interactions. Affiliative, avoidance, and aggressive behaviors were examined in rats 20 h after the 1st, the 8th, and the 15th injection of 10 mg/kg of PCP or of a saline vehicle. PCP treatment reduced the initiation of affiliative contacts with a control congener and increased aggressive responses, in the absence of drug outcomes on time spent in social interaction.

Lesions of the dorsal subiculum and the dorsal hippocampus impaired pattern separation in a task using distinct and overlapping visual stimuli.

The contribution of the dorsal subiculum (DS) and of the dorsal hippocampus (DH) to memory for distinct and overlapping visual stimuli was examined. Rats with selective lesions of the DS or the DH were compared to sham-operated rats on a delayed matching-to-place task guided by distal visual cues in a modified radial-arm maze. Overlapping distal visual cues could be perceived from three arm entrances (adjacent arms) and a unique set of distal cues were more likely to be seen from the other two arm entrances (distinct arms).

Dissociable onset of cognitive and motivational dysfunctions following neonatal lesions of the ventral hippocampus in rats.

This research examined cognitive and motivational processes at different developmental stages in rats with neonatal ventral hippocampus (VH) lesions, an approach used to model schizophrenia. In Experiment 1, performance in a T-maze alternation task was assessed on postnatal days (PNDs) 22 and 23. VH-lesioned rats displayed a severe deficit relative to controls.

Neonatal ventral hippocampus lesions disrupt extra-dimensional shift and alter dendritic spine density in the medial prefrontal cortex of juvenile rats.

Recent data showed that neonatal ventral hippocampus (VH) lesions, an approach used to model schizophrenia symptoms in rodents, produce premature deficits of working memory believed to be associated with early medial prefrontal cortex (mPFC) maldevelopment. This experiment expands the investigation of mPFC integrity in juvenile rats with neonatal VH lesions by assessing behavioral flexibility and dendritic spine density. Sixteen Sprague-Dawley male pups received bilateral microinjections of ibotenic acid in the VH or SHAM surgery on postnatal day (PND) 6.

Dorsal, ventral, and complete excitotoxic lesions of the hippocampus in rats failed to impair appetitive trace conditioning.

Three experiments examined appetitive trace and delay conditioning of the licking response (LR). In Experiment 1, normal rats were trained in trace conditioning using different trace intervals (2, 4, or 8s) and in delay conditioning (i.e.

Processing idiothetic cues to remember visited locations: hippocampal and vestibular contributions to radial-arm maze performance.

This research examined whether rats can use idiothetic cues to form spatial memories in the radial-arm maze (RM) and whether the hippocampus is involved in such ability. A possible contribution of the vestibular system to RM performance was also investigated. Rats with excitotoxic hippocampal lesions and sham-operated controls were trained on two versions of the RM task.

Delayed alternation performance following subchronic phencyclidine administration in rats depends on task parameters.

The cognitive effects of subchronic phencyclidine administration in rats are still unsettled in the literature. Possible causes of discrepancies are different drug treatment regimens and task parameters. The current experiment tested whether variations in procedures of the delayed T-maze alternation task result in performance differences following identical PCP treatments.

Contributions of the dorsal hippocampus and the dorsal subiculum to processing of idiothetic information and spatial memory.

It is well established that the dorsal hippocampal formation is crucial for spatial memory in rats. However, little is known about the distinct functions of the dorsal hippocampus and the dorsal subiculum. To examine the role of the dorsal hippocampus and the dorsal subiculum, Long-Evans rats with excitotoxic lesions (NMDA) of the dorsal hippocampus (DH), the dorsal subiculum (DS), or both (DHDS), and controls were trained on a nonmatching-to-place task.

Enhanced anxiety follows withdrawal from subchronic exposure to phencyclidine in rats.

Anxiety was assessed in rats treated with 5mg/kg of PCP bid for 7 days. One week after withdrawal, measures were collected in the light/dark apparatus and during exposure to a cat odor. PCP decreased time spent in the lit area and number of contacts with a cat collar.

Transient hypolocomotion in rats repeatedly exposed to phencyclidine: an appraisal of motor function and motivation.

Spontaneous locomotion in rats is reduced about 20 h following phencyclidine (PCP) exposure. Our primary purpose was to test if locomotor irregularities would outlast drug withdrawal and be modulated by a periodic auditory stimulation during or after repeated injections. To circumscribe plausible interpretations, motor coordination and motivation were assessed as well.

Performance on spatial working memory tasks after dorsal or ventral hippocampal lesions and adjacent damage to the subiculum.

Rats with excitotoxic lesions of the dorsal or ventral hippocampus and control rats were trained on 2 spatial working memory tasks: the standard version of the radial maze with 8 baited arms and the non-matching-to-place procedure in the T maze. Dorsal lesions produced deficits in both tasks, whereas ventral lesions did not affect learning in either of them. A volumetric analysis of subicular damage showed that dorsal hippocampal lesions caused a deficit in the non-matching-to-place only when accompanied by damage to the dorsal subiculum; on the other hand, lesions to the dorsal hippocampus impaired performance in the radial-arm maze regardless of the extent of subicular damage.

Repeated subchronic exposure to phencyclidine elicits excessive atypical grooming in rats.

Self-grooming in rodents is stereotypically sequenced and naturally occurs after arousal, novelty, or stress. Grooming expression and syntax resulting from stressful and appetitive conditions were assessed in male Long Evans rats treated daily with 10mg/kg of phencyclidine (PCP) for 15 days. Approximately 20 h after the 1st, the 8th, and/or the 15th injection, grooming was induced with water sprays, a loud sound, or smearing food.

Rule shift under long-term PCP challenge in rats.

Performance of Long-Evans rats repeatedly treated with a high dose of phencyclidine (PCP) was compared with that of controls on two tasks involving rule shifts. Fifteen hours after receiving 12 daily doses of PCP (10mg/kg) or saline, rats were tested in the first task where a fixed or variable goal had to be recognized among four maze-arm locations. After receiving the last of 33 injections, rats were subjected to a second task: they had to discriminate the relevant perceptual dimension in a pair of stimuli and choose the appropriate stimulus in each problem.

Modulation of the impairment of hippocampectomized rats on the radial-arm maze cue task by visual characteristics and subicular damage.

Rats with N-methyl-D-aspartate lesions of the hippocampus that partially damaged the subiculum and controls were trained on 2 versions of the radial-arm maze cue task, with either proximal or distal visual stimuli. In Experiment 1, the relative positions of the stimuli varied across trials. Lesioned rats were impaired when trained on the distal version, as opposed to transiently slowed down when trained on the proximal version.

Impaired performance of fornix-transected rats on a distal, but not on a proximal, version of the radial-arm maze cue task.

Fornix-transected and sham-operated rats were trained on radial maze cue tasks in which the relative positions of the cues were either fixed (F condition) or varied (V condition) across trials. Proximal and distal visual stimuli were used in 2 different experiments. With proximal stimuli, fornix-transected rats were transiently impaired in the V condition and performed as well as controls in the F condition.

Schizophrenia-like syndrome inducing agent phencyclidine failed to impair memory for temporal order in rats.

Although subchronic phencyclidine (PCP) administration is recognized as a probative method to model schizophrenia-like symptoms in animals, only a few sets of data support the hypothesis of a cognitive prefrontal cortex (PFc) dysfunction in PCP-treated monkeys and rodents. Two experiments were here conducted to further test the integrity of prefrontal function in two versions of a memory for temporal order (MTO) task administered to rats. Original versions of this task elaborated by Kesner repeatedly yielded moderate to severe performance deficits in PFc lesioned rats.

Selective impairments in rats on an odor-guided continuous delayed nonmatching-to-sample (cDNMS) task after fornix transection.

The two experiments reported in this article examined recognition of simple and complex olfactory stimuli. In Experiment 1, three groups of control rats were trained to criterion without delay then, tested with delays on a continuous delayed nonmatching-to-sample (cDNMS) task using one of three kinds of odor pairs: replicates of the same odor (S), different odors that were each common with another pair (O), different odors with no overlap between pairs (NO). Results showed that initial learning and performance with delays were both poorer for O pairs than for S and NO pairs.

Spatial memory and choice behavior in the radial arm maze after fornix transection.

In the radial arm maze task, it is well established that performance of rats with hippocampal damage is severely impaired on the place version, which relies heavily, if not exclusively, on spatial information. However, very little is known about the effects of hippocampal damage on actual choice behavior. To address this issue, sham-operated (SH) and fornix-transected (FX) rats were trained and tested on the place task in the eight-arm radial maze.