Search results for "rabbits"

Short-term atorvastatin treatment does not modify neointimal morphology but reduces MMP-2 expression in normocholesterolemic rabbit stented arteries.

2006

The aim of our study was to explore some potential pleiotropic effects of atorvastatin, after stenting in the iliac arteries of normocholesterolemic rabbits. On day 0, 27 rabbits underwent stent implantation and were randomized into either the control group (standard chow, CTRL, n = 15) or the atorvastatin group (10 mg/kg/d per os, Ator, n = 12). On day 30, the stented arteries were harvested for histomorphometry and neointimal analysis [macrophages, matrix metalloproteinases (MMP-2), tissue inhibitor of metalloproteinase-2, vascular smooth muscle cells, and collagen]. Atorvastatin did not induce significant histomorphometric and inflammatory modifications but reduced neointimal expression …

Permeability of the bladder mucosa to thiotepa, adriamycin, and daunomycin in men and rabbits.

1976

The permeability of the bladder mucosa to thiotepa and to the anthraquinonic antibiotics, adriamycin and daunomycin, was investigated both in humans and in experimental animals. Instillations in rabbits were performed either in intact males or in animals with ligated ureters. Absorption of thiotepa was significantly higher than that of the antibiotics both in men and in rabbits. Furthermore, a qualitative difference was observed in rabbits in relation to time and with regard to fixation to vesical tissues. In man, absorption was highest after transurethral surgery. It was also increased in cases with extensive anaplastic tumours or in the presence of acute inflammatory reactions.

Erythropoietin and its lost receptor

2007

Pathogenesis of circulatory reactions triggered by nervous reflexes during the implantation of bone cements.

1983

Circulatory and respiratory reactions during the implantation of joint endoprostheses have been observed for years. The components of the bone cements used for anchoring (methyl methacrylate monomer) or the outpour of bone marrow substances from the affected bone marrow cavity are thought to be chiefly responsible for these effects. However, our previous investigations demonstrated unambiguously that reactions of this type can be attributed to direct nervous-reflex mechanisms triggered by the pressure rise in the medullary canal, and that, in addition, bone marrow embolism plays a part in serious circulatory incidents. The investigations on which the present paper is based have confirmed th…

Are dendrites in Drosophila homologous to vertebrate dendrites?

2005

AbstractDendrites represent arborising neurites in both vertebrates and invertebrates. However, in vertebrates, dendrites develop on neuronal cell bodies, whereas in higher invertebrates, they arise from very different neuronal structures, the primary neurites, which also form the axons. Is this anatomical difference paralleled by principal developmental and/or physiological differences? We address this question by focussing on one cellular model, motorneurons of Drosophila and characterise the compartmentalisation of these cells. We find that motorneuronal dendrites of Drosophila share with typical vertebrate dendrites that they lack presynaptic but harbour postsynaptic proteins, display c…

Hippocampal theta activity is selectively associated with contingency detection but not discrimination in rabbit discrimination-reversal eyeblink con…

2009

The relative power of the hippocampal theta-band ( approximately 6 Hz) activity (theta ratio) is thought to reflect a distinct neural state and has been shown to affect learning rate in classical eyeblink conditioning in rabbits. We sought to determine if the theta ratio is mostly related to the detection of the contingency between the stimuli used in conditioning or also to the learning of more complex inhibitory associations when a highly demanding delay discrimination-reversal eyeblink conditioning paradigm is used. A high hippocampal theta ratio was not only associated with a fast increase in conditioned responding in general but also correlated with slow emergence of discriminative res…

Multiple-unit responses to pitch changes in rabbits

1996

Multiple-unit activity (MUA) was recorded from the hippocampus (Hc), the visual cortex (VCx) and the cerebellar cortex (CerCx) in rabbits when pitch deviant tones were presented in a series of standard tones (oddball situation) and when standard tones were absent (deviant-alone situation). Significant MMN-like responses (deviant responses minus standard responses in the oddball situation) occurred in Hc, reflecting a MUA increase to the standards and its decrease to the deviants. In accordance with parallel ERPs reported earlier, the MMN-like responses reflected responses only to different presentation frequencies of stimuli. Non-selectivity in the pitch of such responses in VCx and a lack …

A window amplitude discriminator with adjustable upper and lower thresholds

1976

An amplitude window discriminator is described which permits selection of spikes from a multi-unit recording, provided the signal-to-noise ratio is high enough. The device can be built at relatively low cost and time. The circuitry permits analysis of the positive or the negative deflections of the recorded signals. In Part One of the circuitry, the signals are pre-amplified and may be inverted in polarity. In Part Two, the pulses are compared to a variable lower threshold voltage, and low amplitude noise is eliminated. Part Three depicts a logic circuit for elimination of disturbing high-amplitude signals, whose output delivers digital pulses, each corresponding to an original signal (e.g.…

Hippocampal evoked potentials to pitch deviances in an auditory oddball situation in the rabbit: no human mismatch-like dependence on standard stimul…

1995

Hippocampal auditory evoked potentials (AEP) were recorded in 10 rabbits when pitch deviant tones occurred in a series of standard tones (oddball situation). In control recordings, deviant tones were presented without intervening standard tones (deviant-alone situation). All AEP deflections observed in the oddball situation were found also in the deviant-alone situation. Thus, it appeared that none of the AEP deflections to deviant tones in the oddball situation was specific to a memory trace of preceding standard tones. This observation was in contradiction to such a specificity of the mismatch negativity (MMN) found in humans. Instead, a connection to a neuronal orienting reaction interpr…

The effect of rewarding hypothalamic stimulation on behavioral and neural hippocampal responses during trace eyeblink conditioning in rabbit (Oryctol…

2005

Rabbits were trace-conditioned with a tone as a conditioned stimulus and an airpuff as an unconditioned stimulus. Electrical stimulation to the medial forebrain bundle in the lateral hypothalamus was delivered either before or after the tone-airpuff pair. The purpose of the present study was to test whether the effect of post-trial hypothalamic stimulation differed from the effect of pre-trial hypothalamic stimulation on trace conditioning in the same subjects. Additionally, hippocampal responses were measured during sessions to see if hypothalamic stimulation activated dopaminergic fibres and affected hippocampal cell functioning and thus learning. The results showed that behavioral nictit…