Postrhinal (POR) or perirhinal (PER) cortex damage impairs acquisition and expression of contextual fear, but the nature of the impairment remains unclear. This study used a contextual fear discrimination paradigm that biased subjects toward using a configural, rather than an elemental, strategy to distinguish between 2 contexts, I of which was paired with a mild footshock. Control rats discrim...

The Pharmacovigilance Centre Lareb received 621 reports of possible adverse drugs reactions on Diane-35® . Of all reports, 388 were received after media attention. Of the 309 reports of thromboembolic adverse drugs reactions, 18 cases were fatal. In 31 cases the thromboembolic adverse drugs reaction was initially not recognized as such. The analysis and the turmoil of the 'Diane affair' gave ri...

Three experiments examined the effects of perirhinal cortex lesions on rats' retrograde and anterograde memory for object-discriminations and water-maze place-memory problems. In Experiment 1, rats learned two object-discriminations - the first was learned 2 weeks before surgery and the second 24 h before surgery. Rats with perirhinal cortex lesions displayed mildly impaired retention of both o...

The responses of high-level neurons tend to be mixtures of many different types of signals. While this diversity is thought to allow for flexible neural processing, it presents a challenge for understanding how neural responses relate to task performance and to neural computation. To address these challenges, we have developed a new method to parse the responses of individual neurons into weigh...

The first direct spectroscopic evidence and characterization of triplet states in a molecular dication is reported. The 'II, ,ZU+ electronic absorption between excited states of N22+ is recorded by ion-laser coaxial beam photofragmentation spectroscopy. Over 300 rotational lines are resolved, and 13 parameters characterizing the upper and lower electronic states are determined. The results are ...

We developed a behavioral paradigm for the rat that made it possible to separate the evaluation of memory functions from the evaluation of perceptual functions. Animals were given extensive training on an automated two-choice discrimination task and then maintained their memory performance at a high level while interpolated probe trials tested visual perceptual ability. The probe trials systema...

Performance on tests of source memory is typically based on recollection of contextual information associated with an item. However, recent neuroimaging results have suggested that the perirhinal cortex, a region thought to support familiarity-based item recognition, may support source attributions if source information is encoded as a feature of the relevant item (i.e., "unitized"). The author...

Rats with lesions in the perirhinal cortex and their control group learnt to discriminate between mirror-imaged visual landmarks to find a submerged platform in a watermaze. Rats initially learnt this discrimination passively, in that they were repeatedly placed on the platform in one corner of a square watermaze with walls of different appearance, prior to swimming to that same location for th...