Dianne E Dewey

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Glycinergic synapses play a major role in shaping the activity of spinal cord neurons. The spatial organization of postsynaptic receptors is likely to determine many functional parameters at these synapses and is probably related to the integrative capabilities of different neurons. In the present study, we have investigated the organization of gephyrin(More)
1. Cholinergic terminals in the rat spinal cord were revealed by immunohistochemical detection of the vesicular acetycholine transporter (VAChT). In order to determine the relationships of these terminals to Renshaw cells, we used dual immunolabelling with antibodies against gephyrin or calbindin D28k to provide immunohistochemical identification of Renshaw(More)
Recent studies have shown that at least some of the functional effects of serotonin (5-HT) on motoneuron excitability are direct and are mediated via postsynaptic 5-HT receptors on motoneurons. To determine the spatial distribution of direct inputs from the serotonin system on the proximal and distal dendrites of individual motoneurons, we examined(More)
The morphological and electrotonic properties of 4 motoneurons, 8 Ia inhibitory interneurons, and 4 Renshaw cells were compared. The morphological analysis, based on 3-D reconstructions of the cells, revealed that dendrites of motoneurons are longer and more extensively branched. Renshaw cells have dendrites that are shorter and simpler in structure.(More)
Axotomized motoneurons display drastic modifications in synaptic structure and function related to their disconnection from the periphery and establishment of a regenerative metabolic functional mode. The molecular basis of these modifications is not fully understood. Here we describe changes in metabotropic glutamate receptor 1a (mGluR1a)-immunoreactivity(More)
Serotonin (5-HT) exerts a variety of effects on the excitability of motoneurons, interneurons, and ascending tract cells. Spinocerebellar-tract cells in the dorsal horn receive synaptic connections from serotoninergic axons, but little is known about the relationships between serotoninergic axons and dorsal spinocerebellar tract (DSCT) cells in Clarke's(More)
Excitatory glutamatergic neurotransmission at Ia afferent-motoneuron synapses is enhanced shortly after physically severing or blocking impulse propagation of the afferent and/or motoneuron axons. We considered the possibility that these synaptic changes occur because of alterations in the number or properties of motoneuron(More)
Inhibitory synaptic inputs to Renshaw cells are concentrated on the soma and the juxtasomatic dendrites. In the present study, we investigated whether this proximal bias leads to more effective inhibition under different neuronal operating conditions. Using compartmental models based on detailed anatomical measurements of intracellularly stained Renshaw(More)
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