Recently, vast studies have been focused on the antinociceptive and anesthetic effects of α2 adrenergic receptors, using specific drugs such as medetomidine and dexmedetomidine. In the present study, we tried to assess the peripheral and central effects of dexmedetomidine in phasic and tonic pain, on rats, using tail flick and formalin tests. Dexmedetomidine, administered intraperitoneally (25,...

To determine quantitative REM sleep muscle tone in men and women without REM sleep behavior disorder, we quantitatively analyzed REM sleep phasic and tonic muscle activity, phasic muscle burst duration, and automated REM atonia index in submentalis and anterior tibialis muscles in 25 men and 25 women without REM sleep behavior disorder. Men showed significantly higher anterior tibialis phasic m...

A tonic inhibitory conductance mediated by GABA(A) receptors that supplements the phasic inhibition produced by IPSCs has been identified in the hippocampus and cerebellum. It is presently unknown whether tonic and phasic inhibitions are mediated by GABA(A) receptors with different subunit assemblies. Here we demonstrate that a low concentration (200 nm) of the highly specific competitive GABA(...

Synaptic functional differentiation of crayfish phasic and tonic motor neurons is large. For one impulse, quantal release of neurotransmitter is typically 100-1000 times higher for phasic synapses. We tested the hypothesis that differences in synaptic strength are determined by differences in synaptic calcium entry. Calcium signals were measured with the injected calcium indicator dyes Calcium ...

We have examined kinetics and composition of newly synthesized proteins secreted from cultured atrial myocytes from adult rats. Under unstimulated conditions, noncontracting cultured atrial myocytes, which were pulse-labeled for 10 minutes with [35S]methionine, rapidly released a considerable portion of newly synthesized atrial natriuretic factor (ANF) in a phasic secretion with a peak at 40 to...

Gonadal hormones have been shown to exert modulatory effects on nociception and analgesia. To investigate the role of gonadal hormones in the response by female rats to both phasic and persistent nociceptive stimulation, we evaluated the effects of long-term ovariectomy (OVX, 6 months) on the thermal pain threshold and on formalin-induced responses. The thermal pain threshold was evaluated with...

Thalamic relay neurons have well-characterized dual firing modes: bursting and tonic spiking. Studies in brain slices have led to a model in which rhythmic synchronized spiking (phasic firing) in a population of relay neurons leads to hyper-synchronous oscillatory cortico-thalamo-cortical rhythms that result in absence seizures. This model suggests that blocking thalamocortical phasic firing wo...

Central neurons express a variety of neuronal types and ion channels that promote firing heterogeneity among their distinct neuronal populations. Action potential (AP) phasic firing, produced by low-threshold voltage-activated potassium currents (VAKCs), is commonly observed in mammalian brainstem neurons involved in the processing of temporal properties of the acoustic information. The avian c...

Uterine contractile activity in nonpregnant conscious dogs was investigated based on 2- to 6-mo-long continuous recording by means of a chronically implanted force transducer. We found that nonpregnant uterine contractile activity could be classified into six major patterns: sporadic contractions, weak and strong tonic contractions, weak and strong phasic contractions, and phasic contraction bu...

OBJECTIVES To test the hypothesis that patients with chronic inflammatory pain develop adaptive cortical responses to noxious stimulation characterised by reduced anterior cingulate responses. METHODS Positron emission tomography was used to measure changes in regional cerebral blood flow (rCBF) in response to an acute experimental pain stimulus in six patients with rheumatoid arthritis (RA) ...