Conceptual, Spatial, and Cue Learning in the Morris Water Maze in Fast or Slow Kindling Rats: Attention Deficit Comorbidity

Abstract

Rat lines selectively bred for differences in amygdala excitability, manifested by "fast" or "slow" kindling epileptogenesis, display several comorbid features related to anxiety and learning. To assess the nature of the learning deficits in fast kindling rats, performance was evaluated in several variants of a Morris water-maze test. Regardless of whether the location of the platform was fixed or varied over days (matching-to-place task), the fast rats displayed inferior performance, suggesting both working and reference memory impairments. Furthermore, when the position of the platform was altered after the response was acquired, fast rats were more persistent in emitting the previously acquired response. The poor performance of fast rats was also evident in both cued and uncued tasks, indicating that their disturbed learning was not simply a reflection of a spatial deficit. Moreover, fast rats could be easily distracted by irrelevant cues, suggesting that these animals suffered from an attentional disturbance. Interestingly, when rats received several training trials with the platform elevated, permitting them to develop the concept of facile escape, the performance of fast rats improved greatly. The performance disturbance in fast rats may reflect difficulties in forming a conceptual framework under conditions involving some degree of ambiguity, as well as greater distractibility by irrelevant cues. These various attributes of the fast rats may serve as a potentially useful animal model of disorders characterized by an attention deficit.

Memory deficits and neurochemical changes induced by C-reactive protein in rats: implication in Alzheimer’s disease

“…The Morris water-maze test This was carried out 14-18 days following the microinjection, as described previously with minor modification (Anisman and McIntyre 2002). A circular pool (140 cm in diameter and 45 cm high), which was filled with water (21°C; 37.5 cm deep) made opaque with powdered milk, was divided into four equally spaced quadrants (north, south, east, and west).…”

Development of play fighting in kindling‐prone (FAST) and kindling‐resistant (SLOW) rats: How does the retention of phenotypic juvenility affect the complexity of play?

“…In addition, FAST rats show vigorous struggling throughout the entire test period during physical restraint whereas SLOW rats show a relatively nonhyperactive, immobile posture in the same context. During learning procedures such as the Morris water maze, FAST rats are more easily distracted by irrelevant cues than are SLOW rats, although pretraining can ameliorate these performance deficits (Anisman & McIntyre, 2002). The impulsive nature of FAST rats also is evident in the context of tests for sexual behavior in that the males have difficulty withholding approach responses to nonestrous females .…”

Social isolation is associated with reduced neurogenesis, impaired spatial working memory performance, and altered anxiety levels in male rats

“…We assessed reference memory and working memory using the Morris water maze. 13 Both reference and working memory appeared to decline in isolated rats. In addition, working memory in the probe trial also declined in isolated rats.…”

“…The first trial of each session was considered for evaluating reference memory; however, the other trials (second, third, and fourth) assessed working memory. 13 …”