Antinociceptive effects of color polarized light in animal with formalin test.

Our recent results show the efficacy of pain suppression by exposure of antinociceptive acupuncture points (APs) to white polarized (P) light. But it is known that white light contains electromagnetic waves of different length (colors) and, possibly, not all of them produce a similar effect. There are no comparative data about analgesic affects of the different colors of P light now.

Influences of sensory input from the limbs on feline corticospinal neurons during postural responses.

The dorsal-side-up body posture of standing quadrupeds is maintained by coordinated activity of all limbs. Somatosensory input from the limbs evokes postural responses when the supporting surface is perturbed. The aim of this study was to reveal the contribution of sensory inputs from individual limbs to the posture-related modulation of pyramidal tract neurons (PTNs) arising in the primary motor cortex.

Role of GABA A inhibition in modulation of pyramidal tract neuron activity during postural corrections.

In a previous study we demonstrated that the activity of pyramidal tract neurons (PTNs) of the motor cortex is modulated in relation to postural corrections evoked by periodical tilts of the animal. The modulation included an increase in activity in one phase of the tilt cycle and a decrease in the other phase. It is known that the motor cortex contains a large population of inhibitory GABAergic neurons.

Peripherally applied neuropeptide SF is equally algogenic in wild type and ASIC3-/- mice.

RFa-related peptides play a significant role in the processing of pain in the CNS of mammals. Recently it has been found that, when applied subcutaneously, these peptides elicit a powerful algogenic effect. The question arises whether this peripheral effect can be connected with the ability of RFa-related peptides to decrease the rate of desensitization of acid sensing ionic channels (ASICs) expressed in primary sensory neurons.

Suppression of pain by exposure of acupuncture points to polarized light.

Background: According to clinical studies, the stimulation of acupuncture points (APs) by a variety of methods (eg, needles, pressure, etc) is an effective method for the treatment of many pain syndromes. However, no experimental proof exists showing that the exposure of APs to low-intensity incoherent polarized (P) light evokes an analgesic affect.

Objectives: The authors' previous work, using mice, shows that the exposure of APs to low-intensity microwaves effectively decreases pain.

[Comparative testing of analgesia induced by polarized light and analgetics].

In experiments on mice with the tonic pain locus the comparison of analgesia caused by the action of polarized light on an acupuncture point or by two classic analgetics (analginum, tramadol) was performed. The pain was evoked by hypodermic injection of formalin (30 ml of 5% solution) in the plantar region of hindlimb. Intensity of a pain was judged by duration of painful (licking of the pain locus) and non-painful (slipping, eating, running, washing) behavioral reactions for 60 minutes of observation.

Opioids inhibit purinergic nociceptors in the sensory neurons and fibres of rat via a G protein-dependent mechanism.

We have found that opioid and P2X receptors are functionally coupled in the sensory nerve fibres and neurons of rat. When examined in the skin-nerve preparation, the ATP-evoked discharges of nerve fibres belonging to n. saphenous were inhibited by various opiates in a naloxone-dependent manner.

[Sensitivity to tonic pain and analgin in two lines of mice with knockout genotype].

A comparative study of behavioral reactions (licking of back paw, sleeping, eating, running, washing) in mice with a genetic knockout (lines C57BL/6L and CBA/CaLac) and in control animals was carried out. Experiments have been performed in control conditions (without any influences), after a subcutaneous injection of 5% formalin solution, and also in a case when animals before an injection of formalin received analgin. It was established that the behavior of mice with a genetic knockout without any influences statistically authentically differs from mice without genotype infringements.

RFa-related peptides are algogenic: evidence in vitro and in vivo.

RFamide (RFa)-related peptides modulate pain processing in the mammalian CNS. The effects of these peptides are generally considered as 'anti-opioid'. They also decrease the rate of desensitization of acid-sensing ionic channels (ASICs), putative nociceptors in dorsal root ganglia neurons [C.

[Suppression of visceral pain by action of the low intensity polarized light on acupuncture antinociceptive points].

In experiments on mice, statistically authentic weakening of visceral pain has been shown after an action of low intensity polarized light from a device Bioptron on antinociceptive acupuncture points (AP). Pain was caused by an intraperitoneal injection of 2% acetic acid (0.1 ml/10 g).

[The examination of the analgetic action of polarized light].

The influence of lowintensive polarized light on pain and nonepain behavioural responses (BR) was studied in experiments on mice with the locus of tonic pain (phormalin test). It was shown, that the action of polarized light on the acupuncture points (AP) statistically reliable decrease of pain BR (lisking of the locus of a pain), but increase the duration of nonepain BR (sleeping, eating). The analgetic effect depends from a choice of AP and ehpozition.

[Pain relief by low-intensity frequency-modulated millimeter waves acting on the acupuncture points].

Analgetic effect of low-intensive frequency-modulated millimetric waves (MW) was studied in mice with formalin induced nociceptive behavior reaction (licking of defeat hindpaw). MW were applied to the acupoint E 36 of the defeat hindpaw. The following MW were used: 60 GHz (1) and 118 GHz (2) which were modulated by 4 Hz; noise MW within the range of 42-95 GHz (3) and 90-140 GHz (4) which were modulated in accidental order by frequencies 1-60 Hz; combinations of fixed frequencies with noise - 60 GHz + noise 42-95 GHz (5) and 118 GHz + noise 90-140 GHz (6).

The effects of dopamine and serotonin on rat dorsal root ganglion neurons: an intracellular study.

The effects of bath application of dopamine and serotonin (10(-10)-10(-8) M) were studied in the superfused dorsal root ganglia of 30-36-day-old rats by means of the intracellular technique. In the majority of cells, dopamine and serotonin caused depolarization (60% and 64% of the tested cells, respectively). In other cells hyperpolarization, biphasic reactions or absence of responses have been observed.

[The effect of creatine phosphate on reflex transmission in the normal spinal cord and under hypoxic conditions].

The effect of phosphocreatine on reflex transmission in the spinal cord was studied in rats in vivo and in vitro. Low concentrations (10(-8)-10(-6) M) of phosphocreatine facilitated while high concentrations (10(-4)-10(-3) M) inhibited the amplitude of mono- and polysynaptic reflexes. It was found that phosphocreatine decreases the inhibiting action of hypoxia on test responses and accelerates restoration of the reflex transmission in the spinal cord.

[Effect of oxytocin on rat dorsal root ganglia in vitro].

The influence of bath application of oxytocin (OT) was investigated on the isolated dorsal root ganglion (DRG) cells by means of intracellular recording. The results showed that OT evoked depolarization in most cells and affected predominantly the DRG neurons with biophysical+ characteristics inherent in small neurons.

[Effect of serotonin on the background activity of neurons in the isolated spinal cord semisegment of the rat].

The background activity of neurons in the isolated lumbar semisegment of 14-22 days old white rats was investigated before and after bath application of serotonin (5-HT, 1.10(-8)-1.10(-4) mol/l).

[Effect of dopamine on the background and evoked activity of interneurons from isolated spinal cord segments of newborn rats].

The effects of dopamine on the background and dorsal root stimulation-evoked activity of spinal interneurons and on the field potentials in the dorsal horn were studied in the isolated superfused spinal cord of 11-18 days old rats. It was established that application of dopamine in concentration 1.10(-6)-1.

[The action of dopamine and serotonin on the cells of an isolated spinal cord ganglion of the rat].

The effect of bath application of dopamine (DA) and serotonin (HT) was studied in the isolated perfused dorsal root ganglia (DRG) of 30-36 days old rats by means of intracellular technique. 92% of investigated cells responded to the application of DA and 87%--to HT. DA and HT evoked depolarization in most of cells (64.

[Effect of vasopressin on the somatic membrane of spinal ganglion neurons].

The application of vasopressin (VP) in the isolated perfused dorsal root ganglia of 22-36 days old rats was studied by means of intracellular technique. 86.76% of cells have responded to the VP application.

[Effect of vasopressin and oxytocin on the dorsal root potentials of the isolated perfused spinal cord in rat pups].

The effect of vasopressin and oxytocin on the dorsal root potentials were studied in isolated spinal cord of 12-16 days old rats. It was shown that both neuropeptides evoked reversible depression of the dorsal root potential induced by stimulation of the neighbouring dorsal root. Application of vasopressin or oxytocin caused the reversible dose-dependent depolarization in the dorsal root.

[Depolarizing action of dopamine on the endings of the primary afferent fibers of an isolated segment of the spinal cord in rat pups].

The effect of dopamine on the dorsal root potential was studied in the isolated superfused spinal cord of 12-18-day old rats. It was established that application of dopamine in concentration of 1.10(-9)-1.

[Depolarizing action of dopamine on the motor neurons of an isolated segment of the spinal cord in rat pups].

The dopamine effect on the ventral root potential was studied in the experiment with the isolated superfused spinal cord of 13-18-day old rats. It was established that application of dopamine in concentration of 1.10(-6)-1.

[Reactions of neurons of an isolated superfused segment of spinal cord in the immature rat to nociceptive stimulation of an vessel-perfused extremity].

An in vitro preparation for testing nociceptive neuron responses in 2-3 weeks old rats is described. The preparation consists of isolated superfused spinal segment and intravascularly perfused hind limb connected through the dorsal root. Mechanical (prick, pinch) or chemical (intravascular injection of the algogenic substance) nociceptive stimulation of the hind limb induced an increase in discharge frequency of single neurons.