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The foraging of worker bees of Bombus terrestris visiting artificial feeders in a climatic test chamber was investigated. The behaviour of worker bees visiting rewarding and unrewarding feeders is completely different. Of all flower visits to rewarding feeders 94% are probing-visits, i.e. the bees land on the flower and probe for nectar. In contrast, only(More)
Alzheimer disease (AD) is characterized by excessive deposition of amyloid beta-peptides (A beta peptides) in the brain. In the nonamyloidogenic pathway, the amyloid precursor protein (APP) is cleaved by the alpha-secretase within the A beta peptide sequence. Proteinases of the ADAM family (adisintegrin and metalloproteinase) are the main candidates as(More)
Scent-marking of artificial food sources by workers of the bumblebee,Bombus terrestris, was investigated. Odour marks deposited on artificial flowers were subsequently collected and chemically analysed. Alkanes and alkenes were identified as the main components. The behaviour mediating capacity of synthetic mixtures of the identified compounds was(More)
Outer hair cells were isolated from the guinea pig cochlea using a micromechanical non-enzymatic procedure. Depolarization of outer hair cells in the presence of 25-125 mM K+ was accompanied by a longitudinal contraction of the isolated cells. A decrease of [K+] to 5.4 mM interrupted contraction and induced a relaxation. Individual hair cells were able to(More)
The behavioural consequences of inhibition of gamma-aminobutyric acid (GABA) uptake were studied. Two GABA uptake inhibitors, tiagabine and SKF 89976-A, were administered to rats, and behaviour was analysed 30 min later in a standard open field, an enriched open field, and an elevated plus-maze. Eight groups of animals received either saline (0.9%),(More)
The present analysis addressed behavioral changes after treatment with 4.5 mg/kg or 18.5 mg/kg of the GABA-uptake inhibitor tiagabine combined with either the benzodiazepine diazepam (1.5 mg/kg) or the imidazopyridine zolpidem (0.05 mg/kg), the latter two acting differentially on GABA(A) receptor subtypes. The study included 97 male PVG/OIaHsd rats. A(More)
The pharmacokinetics of antipsychotic drugs has become an integral part in understanding their pharmacodynamic activity and clinical effects. In addition to metabolism aspects, carrier-mediated transport, particularly secretion by ABC transporters, has been discussed as potentially relevant for this group of therapeutics. In this study, the psychoactive(More)
1. A test battery consisting of a standard open field, an enriched open field and an elevated plus maze was used to study behavior in rats. 2. Male rats of the strains PVG/OlaHsd (PVG) and Sprague-Dawley-Hsd (SPRD) (150-200 g body wt) were used to assess interstrain differences as well as handling effects. In a subsequent experiment an other set of male PVG(More)
Central cholinergic neurotransmission was studied in learning-impaired transgenic mice expressing human acetylcholinesterase (hAChE-Tg). Total catalytic activity of AChE was approximately twofold higher in synaptosomes from hippocampus, striatum and cortex of hAChE-Tg mice as compared with controls (FVB/N mice). Extracellular acetylcholine (ACh) levels in(More)