(-)-Linalool, a naturally occurring monoterpene compound, impairs memory acquisition in the object recognition task, inhibitory avoidance test and habituation to a novel environment in rats.

It is known that (-)-linalool is a competitive antagonist of NMDA receptors, which play a key role in the learning and memory processes; however, only a few studies have reported a possible interference of (-)-linalool in memory. The purpose of this study was to investigate the (-)-linalool effects on acquisition of short- and long-term memories through the objects recognition task, inhibitory avoidance test and habituation to a novel environment. Furthermore, the open field test was used to investigate the interference of (-)-linalool in motivation, locomotion and exploration by animals. Wistar male adult rats received an intraperitoneal injection (i.p.) of saline (NaCl 0.9%), tween 5% or (-)-linalool (50 or 100 mg/kg) before training in the tasks; MK-801 (0.1 mg/kg), a glutamate antagonist, was used as positive control. Short-term (STM) and long-term (LTM) memories were tested 1.5 and 24 h after training, respectively, in the inhibitory avoidance and recognition objects. The results suggested that (-)-linalool (as 50- and 100-mg/kg doses) impaired LTM acquisition, but not STM acquisition, in the object recognition task. In the inhibitory avoidance test, animals receiving linalool (both doses) showed impairment in acquisition of both memories measured. In the open field test, the animals that received (-)-linalool showed no significant difference in the crossings and latency to start the locomotion in any of the doses tested, although (-)-linalool 100 mg/kg reduced rearing behavior. When re-exposed to open field 24 h after training, the rats that received (-)-linalool 100mg/kg showed no habituation. Taken together, these data suggested that (-)-linalool was able to impair the acquisition of memory in rats, which can be associated to (-)-linalool antagonist capacity as regards NMDA glutamatergic receptors, since other glutamate antagonists also seem to affect memory.

Use of computer assisted and interactive cognitive training programmes with moderate to severely demented individuals: a preliminary study.

The purpose of this study was to investigate the potential effects of interactive cognitive training and computer-assisted programmes in reducing decline in older adults with dementia. The primary goal of this programme was to maintain participants' level of cognitive function. This study included six moderately to severely demented older adults living in a secured memory-impairment unit within an assisted living community. The participants were assessed with neuropsychological tests prior to, and immediately following, an intensive six-week cognitive training programme. The results showed that the participants improved significantly on measures of overall cognitive function, including short-term memory and cognitive failures. Caregiver reports also indicated significant improvement in the participants' behaviour signs and socialization. Additionally, these participants did not demonstrate significant decline on any of the measures from pre-test to post-test levels. This preliminary study indicates that a combined interactive cognitive training and individual-based computer training programme may effectively reduce decline and even improve some cognitive and behavioural functioning in demented older adults. A follow-up of the participants after four weeks of no training revealed some decline in some of the cognitive and behavioural measures, thus supporting the effectiveness of the training programmes.