Victor A. Derkach

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Substantia gelatinosa (SG, lamina II) is a spinal cord region where most unmyelinated primary afferents terminate and the central nociceptive processing begins. It is formed by several distinct groups of interneurons whose functional properties and synaptic connections are poorly understood, in part, because recordings from synaptically coupled pairs of SG(More)
Thin afferent axons conduct nociceptive signals from the periphery to the spinal cord. Their somata express two classes of Na+ channels, TTX-sensitive (TTX-S) and TTX-resistant (TTX-R), but their relative contribution to axonal conduction and synaptic transmission is not well understood. We studied this contribution by comparing effects of nanomolar TTX(More)
Functional studies of neuronal networks require recordings from visually identified neurons in their natural environment preservation of which may demand experimenting with a tissue of a significant depth or the entire brain. Here we describe a new technique of single-cell imaging and visually controlled patch-clamp recordings in both brain slices of(More)
Post-synaptic currents and responses to ionophoretically applied acetylcholine (ACh) were recorded at 34-37 degrees C from rabbit superior cervical ganglion neurones clamped at -80 mV membrane potential. Atropine (1 microM) was used to block muscarinic receptors. The fast excitatory post-synaptic current (e.p.s.c.) reversed at -9.6 +/- 1.7 mV and decayed(More)
The central nervous system controls food consumption to maintain metabolic homoeostasis. In response to a meal, visceral signals from the gut activate neurons in the nucleus of the solitary tract (NTS) via the vagus nerve. These NTS neurons then excite brain regions known to mediate feeding behaviour, such as the lateral parabrachial nucleus (PBN). We(More)
We study a stepwise algorithm for solving the indefinite truncated moment problem and obtain the factorization of the matrix describing the solution of this problem into elementary factors. We consider the generalized Jacobi matrix corresponding to Magnus’ continuous P -fraction that appears in this algorithm and the polynomials of the first and second kind(More)
Although it is known that each spinal cord segment receives thin-fibre inputs from several segmental dorsal roots, it remains unclear how these inputs converge at the cellular level. To study whether C- and Adelta-afferents from different roots can converge monosynaptically on to a single substantia gelatinosa (SG) neurone, we performed tight-seal(More)
1. The elementary currents flowing through single channels opened by acetylcholine were recorded in rat superior cervical ganglion neurones using patch-clamp methods. Acetylcholine (30 microM) was included in the patch electrode (cell-attached recordings) or applied by ionophoresis (outside-out configuration). All measurements were made at 23-25 degrees C(More)
The actions of bis-ammonium compounds (BAC) on the ionic channels activated by acetylcholine (ACh) were studied in voltage-clamped neurones of rabbit isolated superior cervical ganglion. The kinetics of binding of BAC to open channels was estimated from shortening of the decay of fast excitatory postsynaptic current. The kinetics of dissociation of BAC from(More)
BACKGROUND Substantia gelatinosa (SG, lamina II) is a spinal cord region where most unmyelinated primary afferents terminate and the central nociceptive processing begins. The glutamatergic excitatory interneurons (EINs) form the majority of the SG neuron population, but little is known about the mechanisms of signal processing in their synapses. (More)