[Coupled neuronal reactions of the specific and nonspecific thalamic nuclei to painful and electroacupuncture stimuli]. / Sopriazhennye reaktsii neironov spetsificheskikh i nespetsificheskikh iader talamusa na bolevye i élektroakupunkturnye vozdeistviia.

Electric reactions of neurons of the specific (VPM) and nonspecific (CM PF) thalamic nuclei caused by noxious and electroacupuncture stimulation were studied in acute experiments on cats. About 18% of the investigated neurons demonstrated coupled reactions to afferent stimulation. The coupled reaction to either noxious or electroacupuncture stimulation had inhibitory or activating character. A hypothesis on the existence of functional units responsible for the effects of electroacupuncture analgesia with participation of inhibitory, relay neurons and interneurons is made.

[Modulating effect of electric acupuncture stimulation on the bioelectrical activity of neurons of specific and nonspecific thalamic nuclei]. / Moduliruiushchee vozdeistvie élektroakupunkturnoi stimuliatsii na bioélektricheskuiu aktivnost' neironov spetsificheskikh i nespetsificheskikh iader talamusa.

Bioelectric reactions of individual neurons in specific and nonspecific thalamus nuclei were studied in acute experiments on cats. Auricular or body point electroacupuncture (EAP) was shown to affect the functions of spontaneously active neurons in the nuclei under study. Two types of spontaneously active neurons were identified: some were activated and some inhibited in response to EAP stimulation. The number of neurons activated in response to EAP was 50% greater in specific thalamus nuclei than in nonspecific ones, while inhibition was mostly observed in nonspecific thalamus cells.

[Functional architectonics of neuronal antinociceptive mechanisms during the electroacupuncture method of reflex action]. / Funktsional'naia arkhitektonika neironal'nykh antinotsitseptivnykh mekhanizmov pri élektroakupunkturnom sposobe reflektornogo vozdeistviia.

The peculiarities of neurone bioelectric activity of sensory thalamic nuclei under electroacupuncture (EAP) stimulation have been studied in acute experiments on cats. EAP stimulation has been established to change spontaneous and evoked activity of neurones of sensory thalamic nuclei, that testifies to the development of a new functional state. The functional state of the cortex, in particular the second somatosensory region has been shown to determine the nature of neurone activation of sensory thalamic nuclei during the EAP stimulation. Schemes of possible organization of functional pools realizing the mechanisms of inhibition of nociceptive signals on central neurones during EAP way of reflex stimulation are suggested.

Cortical projections to the periaqueductal grey in the cat: a retrograde horseradish peroxidase study.

Stereotaxic fluid microinjections of horseradish peroxidase into different parts of the rostral and caudal periaqueductal grey (PAG) in cats have provided substantial retrograde evidence that the somatosensory cortex (I and II), frontal cortex, insular and cingular cortex are the principal sources of cortical-PAG projections. The somatosensory cortex II projects to all the regions of the rostral and caudal PAG. The frontal cortex projects to dorso-lateral quadrant of the PAG. The same projections were determined from insular and cingular cortex to PAG. The findings revealed a morphological substratum of corticofugal effects on PAG.

[Corticofugal projections to the periaqueductal gray matter in the cat midbrain]. / Kortikofugal'nye proektsii v periakveduktal'noe seroe veshchestvo srednego mozga koshki.

Stereotaxic microinjections of horseradish peroxidase (HP) were made into different parts of the rostral and caudal periaqueductal gray (PAG) in cats to study corticofugal projections to the PAG. The method of retrograde axonal transport of HP demonstrated labeled neurons in the I and II somatosensory areas, frontal, cingular and insular cortex of the brain. It was shown that the II somatosensory cortex projects to all the areas of the rostral and caudal PAG. The frontal cortex projects to the dorsolateral quadrant of the PAG. The findings obtained enabled the detection of the morphological substrate of the corticofugal effects on one of the antinociceptive brain structures--the PAG.

[Reflexogenic changes in the spontaneous and evoked activity of the parafascicular neurons in the rat thalamus during electroacupuncture stimulation]. / Reflektornoe izmenenie spontannoi i vyzvannoi aktivnosti neironov parafastsikuliarnogo kompleksa talamusa koshki pri élektroakupunkturnoi stimuliatsii.

Acute experiments on cats were made to study the electroacupuncture (EAP) effect on neuronal impulse activity in the parafascicular complex (PFC) of the thalamus in response to solitary peripheral nociceptive and non-nociceptive stimuli. EAP stimulation affects the pattern of spontaneous and evoked activity of PFC neurons and forms their new functional status. It is suggested that the analgetic effect is brought about by the changes in neuronal activity in subcortical structures of the brain including the thalamic nuclei which transmit the ascending nociceptive input.