Spatial working memory improvement by an alpha2-adrenoceptor agonist dexmedetomidine is not mediated through alpha2C-adrenoceptor.

1. Aged alpha2C-adrenoceptor knockout and wild type mice were used to investigate whether alpha2C-adrenoceptors are involved in mediating the beneficial effects of alpha2-adrenoceptor agonist, dexmedetomidine, on spatial working memory. 2.

alpha(2C)-Adrenoceptors modulate the effect of methylphenidate on response rate and discrimination accuracy in an operant test.

The present study investigated the role of alpha(2C)-adrenoceptors in the regulation of activity and discrimination accuracy in an operant chamber test. We trained food deprived control and alpha(2C)-adrenoceptor knockout mice to collect liquid food rewards in an operant chamber during the light (20 s) period. No food reward was delivered during the dark period (40 s).

Hippocampus in Alzheimer's disease: a 3-year follow-up MRI study.

Background: Due to the progressive nature of Alzheimer's disease (AD), it has been proposed that serial imaging studies tracking the course of progression might improve the diagnostic accuracy of AD.

Methods: Longitudinal changes in hippocampal volumes were evaluated using magnetic resonance imaging (MRI) over a period of 3 years in 27 AD patients and 8 control subjects.

Results: A statistically nonsignificant trend towards accelerated volume loss in the AD group compared to control subjects was observed.

Pre-training blocks the improving effect of tetrahydroaminoacridine and D-cycloserine on spatial navigation performance in aged rats.

We investigated the effect of pre-training on the improvement of spatial navigation performance provided by a cholinesterase inhibitor, tetrahydroaminoacridine (3 mg/kg, i.p.), and a positive modulator of NMDA receptor, D-cycloserine (10 mg/kg, i.

Apolipoprotein E-deficient mice are not more susceptible to the biochemical and memory deficits induced by nucleus basalis lesion.

We investigated whether the nucleus basalis lesion induced by quisqualic acid was associated with a more severe impairment of spatial navigation in a water maze, a greater reduction in frontal choline acetyltransferase activity and decrease in the number of choline acetyltransferase-positive neurons in the nucleus basalis in apolipoprotein E-deficient mice than in control mice. We also studied the effect of ageing on water maze spatial navigation and cortical choline acetyltransferase activity in 16-month-old control and apolipoprotein E-deficient mice. We found that the lesion decreased choline acetyltransferase-positive neurons in the nucleus basalis and frontal choline acetyltransferase activity equally in control and apolipoprotein E-deficient mice.