Signe Kjær Nedergaard

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Fast-scan cyclic voltammetry with carbon fibre microelectrodes was used to detect endogenous dopamine (DA) and 5-hydroxytryptamine (5-HT) release from three distinct regions of guinea-pig mid-brain in vitro: rostral and caudal substantia nigra (SN) and the ventral tegmental area (VTA). Previous electrophysiological studies have demonstrated that cells of(More)
Within the substantia nigra, the dendrites of dopaminergic neurons that project to the striatum appear to play an active and nonclassical role in the physiology of the neuron in that they release transmitter and protein, but little is known of the factors controlling release of substances from these dendrites. In this study, we show that(More)
Isolated small intestine of toad (Bufo bufo) was mounted on glass tubes for perfusion studies with oxygenated amphibian Ringer's solution containing glucose and acetate. Under open-circuit conditions (V t =−3.9 ± 1.8 mV, N= 14) the preparation generated a net influx of 134Cs+. The time course of unidirectional 134Cs+-fluxes was mono-exponential with similar(More)
In the substantia nigra pars compacta neurons can be classified in two sub-populations. In this study the distinguishing criteria have been the presence of four distinct calcium-dependent potentials, two each generated selectively and exclusively in each cell type. One class of cells, found in the more caudal pars compacta, displays calcium-mediated, slow(More)
1. The effect of a brief train of electric stimuli in the dorsolateral funiculus on the intrinsic response properties of turtle motoneurones was investigated in transverse sections of the spinal cord in vitro. 2. Even when glutamatergic, GABAergic and glycinergic ionotropic synaptic transmission was blocked by antagonists of AMPA, NMDA, glycine and GABA(More)
Activation of spinal cord microglia and astrocytes is a common phenomenon in nerve injury pain models and is thought to exacerbate pain perception. Following a nerve injury, a transient increase in the presence of microglia takes place while the increased numbers of astrocytes stay elevated for an extended period of time. It has been proposed that activated(More)
Dopamine released from dendrites of nigrostriatal neurones in the substantia nigra exerts an inhibitory action on these cells. However, the spatio-temporal characteristics of the action of dendritic dopamine is still unclear. The aim of the present study was to investigate the responses of these neurones in the guinea-pig to amphetamine, applied locally in(More)
A non-invasive method is applied for studying ion transport by single isolated epidermal mitochondria-rich (MR) cells. MR cells of toad skin (Bufo bufo) were prepared by trypsin (or pronase) treatment of the isolated epithelium bathed in Ca2+-free Ringer. Glass pipettes were pulled and heat- polished to obtain a tip of 2-4 mm with parallel walls and low tip(More)
Evidence is accumulating that a soluble, secretory form of acetylcholinesterase may have novel, non-cholinergic functions in certain brain regions, such as the substantia nigra. In this study, application of human recombinant acetylcholinesterase (rhAChE) to pars compacta neurons in the rostral substantia nigra resulted in a sustained hyperpolarization that(More)
This study evaluates the effects of two learning paradigms, intensive vs. baseline, on the posttraumatic acquisition of a water maze based place learning task. Rats were subjected either to a control operation (Sham) or to a fimbria-fornix (FF) transection, which renders the hippocampus dysfunctional and disrupts the acquisition of allocentric place(More)