Peripheral auditory neurons are tuned to single frequencies of sound. In the central auditory system, excitatory (or facilitatory) and inhibitory neural interactions take place at multiple levels and produce neurons with sharp level-tolerant frequency-tuning curves, neurons tuned to parameters other than frequency, cochleotopic (frequency) maps, which are different from the peripheral cochleoto...

Background In rheumatoid arthritis (RA) and spondyloarthritis (Spa), persistent pain remains challenging. It is thought to result from central sensitisation, which can be measured by quantitative sensory testing (QST) conditioned modulation (CPM). Objectives The main objective of the RAPID (Rheumatism Pain Inhibitory Descending pathways) study, was assess descending (through CPM paradigms) in p...

The rostral ventromedial medulla (RVM) is part of descending circuitry that modulates nociceptive processing at the level of the spinal cord. RVM output can facilitate pain transmission under certain conditions such as inflammation, and thereby contribute to hyperalgesia. Evidence suggests that substance P and activation of neurokinin-1 (NK-1) receptors in the RVM are involved in descending fac...

The spinal mechanisms of action of opioids under normal conditions are reasonably well understood. The spinal effects of opioids can be enhanced or reduced depending on pathology and activity in other segmental and nonsegmental pathways. This plasticity will be considered in relation to the control of different pain states using opioids. The complex and contradictory findings on the supraspinal...

Descending inhibitory and facilitatory influences from the rostroventral medulla (RVM) on responses of lumbosacral spinal neurons to noxious colorectal distension (CRD, 80 mmHg, 20 s) were studied. At 25 sites in the RVM, electrical stimulation produced biphasic effects, facilitating responses of spinal neurons to CRD at lesser intensities of stimulation (5-25 microA) and inhibiting responses o...

The electrophysiological and morphological properties of layer I neurons were studied in visual cortex slices from 7- to 19-d-old rats using whole-cell recording and biocytin labeling. A heterogeneous population of small, nonpyramidal neurons was found. Approximately one third of the cells we recorded were neurogliaform cells; another third were multipolar neurons with axons descending out of l...

Ten patients have been described showing inability to stop breathing on command, spontaneous respiration and voluntary respiratory stimulation being unaffected. This abnormality not previously described in the literature, we feel should be named respiratory inhibitory apraxia (R.I.A.). The anatomical organization of respiration is briefly reviewed. R.I.A. is often associated with other forms of...

  The present study was carried out to explore the possible involvement of the arcuate nucleus of the hypothalamus in the inhibitory descending pain control system associated with the tail flick test and EEG recordings. Adult male (NMRI) albino rats weighing 200 ± 20 g were used. Rats were divided into three groups: experimental, sham and control. The arcuate nucleus was destroyed unilaterally ...