PubMed Health⌕ Search

Biomedical subjects

I I Grachev

Publications and source records attributed to I I Grachev.

At least 37 records · Page 2Linked to original sources
PubMed1977

[Slowly-adapting mechanoreceptor units of the guinea pig mammary nipple].

Slowly--adapting mechanoreceptor units of areola and nipple (MAI and MAII) at rest exhibited spontaneous 1--2/sec firing in 6% only. At constant mechanical displacement of the skin surface. MAI had an irregular firing while MAII--regular one. Mean frequency of MAI and MAII APs linearly depended on the amplitude of mechanical stimulus. trepeated stimulation of MAI and MAII reduced number of APs for each successive stimulus. At sinusoidal mechanical stimulation, the smallest AP threshold for MAI and MAII was about 10--15 Hz.

Adaptation, Physiological↗
PubMed1977

[Properties of mechanoreceptor units of mammary gland parenchyma].

Two types of mechanosensitive units were found in the parenchyma of the rat mammary gland (SA and RA). Most of SA units had a spontaneous activity 1-3/sec. and responded to an abrupt displacement with a decline in the activity for 5-10 sec. RA had no such a response. The relation between average firing rate and displacement velocity at a constant displacement amplitude was linear for both SA and RA. RA however had the velocity threshold higher than SA. The number and frequency of SA afferent impulses decreased at a repeated stimulation. Electron microscopy revealed that free nerve endings correspond to SA and RA.

Action Potentials↗
PubMed1976

[Properties of the mechanoreceptors of the nipple of the guinea pig mammary gland. (Rapidly adapting mechanoreceptor units)].

Two types of rapidly adapting mechanosensitive units have been found in skin of the teat of guinea--pig mammary gland (RA1 and RA2). They wee not both spontaneously active. RA1 and RA2 have no position response. The relation between average frequency of discharge and displacement velocity at a constant displacement amplitude was linear for RA1. With constant velocity displacements, frequency versus displacement curves assume a horizontal orientation of relatively low discharge frequencies and are then displaced upward as velocity increases for RA1. The number and frequency of afferent impulses of RA1 decreased during repeated ramp mechanical stimulation. Vibratory tuning points were in the range of 10--25 Hz for RA1. 20% of mechanosensitive units were RA2, which have a high velocity threshold and rarely produce more than 2--3 impulses to high velocity. The fatigue of RA2 is not prominent. RA1 were classed as the velocity detectors and RA2 as "transient" detectors.

Action Potentials↗
PubMed1976

[Functional characteristics of rapidly adapting mechanoreceptor units of the rat mammary gland nipple].

Two types of rapidly adapting mechanosensitive units were found in the teat of the rat mammary gland (RAI and RAII). Neither was spontaneously active. 10% of the units were RAII and had the functional characteristics of "transient" receptors. The relation between the average frequency of discharge and the velocity of displacement at a constant displacement amplitude was linear for RAI. The latency of the first spike decreased when indentation velocity increased. The number and frequency of afferent impulses decreased at a repeated mechanical stimulation. Vibratory tuning points were in the range 10--25 Hz for RAI. RAI units were not directionally sensitive to the teat displacement.

Action Potentials↗
PubMed1975

[Electrical activity of mechanoreceptor neurons in rat mammary gland nipple skin].

Three types of the mechanosensitive units were found in the skin of the rat mammary gland nipple: receptors detecting: 1) transients, 2) velocity, 3) position and velocity. The 1st and the 2nd types were spontaneously inactive and both adapted rapidly to mechanical stimuli. The 3rd type had a spontaneous activity 1-4/sec and adapted slowly to mechanical stimuli.

Action Potentials↗
PubMed1975

[The influence of oxytocin on the membrane potentials of mammary gland secretory cells].

The effect of oxytocine and its combinations with the acetylcholine, adrenaline, atropin, and prozerin on the level of membrane potential of mammary secretory cells was studied. Short oxytocine application (5-10(-4) ME/ml) evoked hyperpolarization of the contraluminal membrane (12+/-1 mV for 54+/-5 sec). Their response was increased by joint application of acetylcholine or proserine and decreased by preliminary application of atropin. Adrenaline increased or decreased the amplitude of the membrane potential's changes and considerably reduced the duration of the oxytocine reaction. Existence of oxytocine receptors was supposed on the membrane of secretory cells, as well as the possibility of acetylcholine and adrenaline effects on the structure of oxytocine receptors or the interaction of adreno--and cholinergic receptors with the oxytocine those.

Acetylcholine↗