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Recent anatomic results indicate that a large direct projection from the spinal cord to the hypothalamus exists in monkeys. The aim of this study was to determine whether the existence of this projection could be confirmed unambiguously using electrophysiological methods and, if so, to determine the response characteristics of primate spinohypothalamic(More)
Neurobehavioral and neurophysiological actions of the peptide endothelin-1 (ET-1) were investigated after subcutaneous plantar hindpaw injections in adult male Sprague Dawley rats. Hindpaw flinching developed within minutes after ET-1 (8-16 nmol) injection, peaked at 30 min, lasted for 60 min, and was strongly inhibited by the endothelin-A (ET(A)) receptor(More)
BACKGROUND Controversy still surrounds the differential susceptibility of nerve fibers to local anesthetics and its relation to selective functional deficits. In the current study we report features of conduction blockade in different classes of rat sciatic nerve fibers after injection of lidocaine by a percutaneous procedure that closely resembles clinical(More)
Anatomical studies indicate that a relatively large percentage of spinohypothalamic tract (SHT) neurons are located within thoracic spinal segments. The aim of this study was to characterize the responses of SHT neurons in these segments of rats to innocuous and noxious stimulation of the skin and of a visceral structure, the bile duct. In addition, we(More)
Characteristics and reticular mechanisms of two types of late reflex responses (equivalents of the startle reflex) evoked by weak (tactile stimuli) and strong (high-threshold peripheral nerve stimulation) stimulations were studied in chloralose-anesthetized cats; these responses were designated as "tactile" (T) and "spino-bulbo-spinal" (SBS) reflexes,(More)
We developed a relatively inexpensive method for stereotaxic placement of electrodes or needles in the brains of monkeys. Steel balls were affixed to the skulls of monkeys. These balls served as fiducial markers and were also used as points at which the monkey's skull was held in a modified stereotaxic apparatus. Computed tomography (CT) was used to(More)
Phasic respiratory influences on late reflex discharges in the limb and lower intercostal nerves--electrophysiological analogs of somesthetic and acoustic startle reflexes (SR)--were studied in unanesthetized (decerebrated) or chloralose-anesthetized cats. The integrated values of the SR in both types of nerves always essentially decreased during(More)
Experiments on anesthetized cats with partial lesions of the spinal cord show that reticulospinal pathways in the ventral part of the lateral funiculus take part in the polysynaptic reflex inhibition caused by stimulation of ipsi- and contralateral reticular formation. The reticulofugal volley in the ventrolateral funiculus produced relatively short (up to(More)
Influences of bulbar microinjections of some neuromodulator antagonists (methysergide, haloperidol, naloxone) on depression dynamics of spino-bulbo-spinal (SBS) reflex from the periaqueductal grey (PAG) stimulation were studied in chloralose anesthetized rats. Microinjections were made into the reticular gigantocellular nucleus which is a main supraspinal(More)
Influences of separate and combined stimulation of the periaqueductal grey matter (PAG) and the substantia nigra (SN) on startle reflexes were studied in chloralose-anesthetized rats; the reflexes were low-threshold, tactile ones and high-threshold, spino-bulbo-spinal (SBS) ones. A clear interaction between effects of the PAG and SN stimuli occurred by(More)