Behavior and the cholinergic parameters in olfactory bulbectomized female rodents: Difference between rats and mice.

Olfactory bulbectomy (OBX) in rodents induces a wide spectrum of functional disturbances, including behavioral, neurochemical, and neuromorphological alterations. We have examined the effects of OBX on behavior and the parameters of the cholinergic system in female rats and mice. In rats, OBX resulted in the appearance of some depressive-like behavioral marks, such as the decreased sucrose consumption, hyperactivity, impaired short-term memory and anxiety-like behavioral features, such as shortened presence in the center of the open field arena or open arms of the elevated plus-maze and an enhancement of avoidance behavior.

[Glutamatergic excitation of cortical neurons depending on site of origin on the neuronal membrane and cholinergic regulation under hypothermic condition].

In sensorimotor cortical slices of guinea pig in the course of cooling of incubating fluid from 34 to 21-22 delta C it was shown that hypothermia does not influence on the evoked spike reactions to iontophoretic application of glutamate to the soma, but glutamate action on the dendritic locus causes the shot latency somatic spike response during hypothermic increasing of the rate of spontaneous activity and long latency spike response--during hypothermic fall of activity. While the cooling rate of spontaneous activity in the slow firing neurons was mainly increasing and in the high firing neurons (above 4 spikes per second)--decreasing. The changes in spontaneous activity began at 30 degrees C along with the decreased spike reactions to iontophoretic applications of acetylcholine and efficacy of dendro-somatic propagation.

Region-specific changes in activities of cell death-related proteases and nitric oxide metabolism in rat brain in a chronic unpredictable stress model.

Effects of a chronic combined unpredictable stress on activities of two cell death-related proteases, calpain and cathepsin B, were studied along with indices of nitrergic system in rat brain structures. Male Wistar rats were subjected to a 2-week-long combined stress (combination of unpaired flash light and moderate footshock associated with a white noise session). Stress resulted in a significant loss in the body and thymus weight and increased defecation in the open field test, though neither motor and exploratory activity, nor plasma corticosterone differed from the respective control levels.

[Glial satellites as the source of additional energy supply to the neurons during the increased frequency of firing activity].

Using surviving slices of guinea pig somatosensory cortex, it was shown that functionally different regulation of spontaneous firing activity in different neurons corresponded to irregular distribution of glial satellites. Maximal increase of spike activity induced by acetylcholine (up to 36 spikes per second) was detected in "silent" neurons which account for 37.2% of nerve cells in layer V.

[Correlation between activities of neurons of sensorimotor and visual cortices after forming a hidden focus of excitation (defensive dominanta) in cortical representation of a forelimb in rabbits].

The interaction between neurons of sensorimotor and visual cortices was investigated by cross-correlation analysis. In this interaction, we examined the role of sensorimotor neurons responding to light. In rabbits with a hidden focus of excitation, neurons of the sensorimotor cortex responding to light significantly more often formed correlation joints with cells of the visual cortex than neurons not responding to light.

[The temperature regulation of the spontaneous activity frequency and the concomitant changes of the cortical neurons' spike amplitude].

In the sensorimotor cortical slices of guinea pigs, the rate of neurons' spike activity increased at 27-29 and 34-36 degrees C. The change of the firing rate was accompanied by a drop in the spike amplitude at the temperature below 27 and above 34 degrees C. Usually after cooling to 24 degrees C the spike amplitude fully restored when the temperature increased to 32-34 degrees C.

[Behavior of rats after immobilization and structural reorganization in the motor cortex and hippocampus].

Behavioral changes and accompanying morphological neuron-glia reorganization in the rat brain were analyzed after long-term immobilization. Wistar rats (n = 23) were stressed by interruptive immobilization, which was carried out within three week daily for 7-8 h. Behavioral immobilization of rats was accompanied by a decrease in the locomotor and exploratory activity in "open field" test and increase in the number and duration of freezing episodes.

Comparison of the behavior of rats after immobilization with structural changes in the motor cortex.

Behavioral and neuronal-glial changes after emotional stress induced by discontinuous (7-8 h per day for one week) immobilization were compared in Wistar rats (n = 20). Immobilization led to increases in horizontal and vertical activity and the duration of "comfort" grooming in the open field test. Morphometric measurements demonstrated significant increases in the density of hypoxic neurons in the motor area of the right hemisphere of experimental animals as compared with measures in controls.

[Effects of human and rat interferons-alpha on the behavior of rats of different ages. Comparative study of the homology of amino acid sequences].

Effects of chronic intranasal administration of human and rat interferons alpha on feeding and defensive behavior of rats were studied. Natural leukocyte human interferon "Lokferon" (a mixture of alpha interferon subtypes) and recombinant rat interferon alpha of the first subtype were used in the dose of 350 ME per rat daily. In addition, using the databases NCBI and EBI, we quantitatively estimated homology of amino-acid sequences between different subtypes of human and rat interferons.

[Correlation of the rat behavior after immobilization with structural reorganization in the motor cortex].

Behavioral changes and accompanying morphological neuron-glia reorganization in the rat brain were compared after emotional stress. Wistar rats (n = 20) were stressed by the interrupted immobilization, which was carried out during one week 7-8 h daily. Behavioral immobilization of rats was accompanied by an increase in horizontal and vertical locomotors activity and in duration of the III and IV phases of grooming ("comfortable" grooming) in the "open field" test.

[Effect of apomorphine injection into the nucleus accumbens on the limb preference in manipulation movements in rats].

The concentration of dophamine and its derivates is known to correlate with the degree of handedness in manipulative movements in rodents. In this work we studied a possibility to changing handedness in rats by injection of a dopamine agonist into the nucleus accumbens. Retrieving food from a horizontal tube was used to determine the limb preference (10 food retrievals by the preferred limb).

[Synchronization of electrical field potentials in neocortex of rat after isolation of a cortex island in the contralateral brain hemisphere].

A correlation between the number of boutons and synchronization of electrical activity in two sites of the intact right somatosensory cortex of rats was anakyzed at different stages of axonal sprouting elicited by isolation of a cortex slab in the left cortex. Time delay between the development of epileptiform field potentials in two sites of intact cortex located at a distance of 4 mm from each other was determined as a parameter of synchronization. The analysis was carried out in 30 and 90 days after the complete isolation of the neural island in a symmetrical site of the contralateral cortex.

[Effect of small doses of interferon-alpha on food conditioning in young and ageing rats].

Low doses (10 or 350 ME) of human interferon-alpha (HIA) were intranasally applied to young (3-4 months) and ageing (12-15 months) Wistar rats during food conditioning. In control groups, development of the conditioned reflex to acoustic stimulus (tone) did not differ significantly in young and ageing rats in the course of chronic applications of the HIA. However, the control ageing rats were better than young rats in time-interval conditioning.

[Influence of small doses human interferon-alpha intranasal injection on behavior of rats of different age].

Behavior of young (3-4 month old) and ageing (12-15 month old) rats was studied during chronic intranasal application of low doses (10 ME or 350 ME) of human interferon-alpha (HIA). In ageing rats HIA did not affect dynamics (days 0th, 8th and 16th) of (a) locomotive and (b) investigative activity in the "open field" test and in two-side defensive conditioning, and (c) decreased anxiety ("open field", "light-darkness" test). In young rats HIA (a) increased locomotive activity by 16th day (it decreased in control), (b) investigative activity did not change (in control it decreased by 8th day; "open field" test), (c) anxiety decreased in the "open field" and increased in "light-darkness" tests, (d) development of conditioned reflex improved (during 2nd learning session in 5 days after the first one).

Acquisition of a conditioned avoidance reflex and morphometric characteristics of the sensorimotor cortex in rats subjected to social deprivation in early ontogenesis.

Male Wistar rats were subjected to social deprivation from day 22 to day 70 of postnatal development to form a group of isolants. Measures of learning of a passive avoidance and the results of training to active avoidance of painful electrical stimulation in these rats were significantly lower at age 110-120 days than in control rats. The characteristics of movement activity in isolants during training and testing, as well as in the open field test, probably resulted from their high levels of anxiety.

The temperature sensitivity of the cholinergic responses of cortical neurons in the guinea pig brain.

Studies on slices of the parietal cortex of the guinea-pig brain showed that a change in temperature from 20 degrees C to 36 degrees C led to increases in responses to microintophoretic application of acetylcholine to individual nerve cells. The greatest changes occurred over two temperature ranges: 27-29 degrees C and 34-36 degrees C. Increases in the cholinergic response were accompanied by increases in the spontaneous activity of the neurons.

[Avoidance conditioning and morphometric characteristics of the sensorimotor cortex of rats exposed to social deprivation in early ontogeny].

Male Wistar rats were exposed to social deprivation in the period from the 22nd to 70th days of postnatal development. The characteristics of the learning of these rats at the age 110-120 days in the passive avoidance box and during training for active avoidance of electroshock were significant lower than those of control animals. Features of motor activities of the "isolants" in learning and testing, and in the "open field" may be related to their higher anxiety level.

Prodynorphin transcripts and proteins differentially expressed and regulated in the adult human brain.

Transcription from multiple promoters along with alternative mRNA splicing constitutes the basis for cell-specific gene expression and mRNA and protein diversity. The prodynorphin gene (PDYN) gives rise to prodynorphin (PDYN), precursor to dynorphin opioid peptides that regulate diverse physiological functions and are implicated in various neuropsychiatric disorders. Here, we characterized PDYN transcripts and proteins in the adult human brain and studied PDYN processing and intracellular localization in model cell lines.

[A comparative study of antistroke activity of the new drug "cerebral" and its fractions in rats].

The effect of the new drug "cerebral" and its fractions 1-3 on the model of bilateral hemorrhagic stroke in white rats was studied with reference to the action of cebrolysin and cerebrolysate-M. With respect to the general functional state, behavioral activity restoration, and morphological data, the most pronounced antistroke action was observed for the cerebral-1 fraction. This fraction was further separated into three subfractions.

Translocation of dynorphin neuropeptides across the plasma membrane. A putative mechanism of signal transmission.

Several peptides, including penetratin and Tat, are known to translocate across the plasma membrane. Dynorphin opioid peptides are similar to cell-penetrating peptides in a high content of basic and hydrophobic amino acid residues. We demonstrate that dynorphin A and big dynorphin, consisting of dynorphins A and B, can penetrate into neurons and non-neuronal cells using confocal fluorescence microscopy/immunolabeling.

Intracortical synchronization of epileptic discharges at different stages of ultrastructural rearrangements in a completely neuronally isolated area of rat neocortex.

Cross-correlation functions were used to study the time delay (a measure of synchronization) in the appearance of epileptic discharges in distant areas of the cortex in the intact cortex and in neuronally isolated cortical strips in Wistar rats. Experiments were performed at different stages of axon sprouting 30 and 90 days after isolation of cortical areas and in intact cortex. Significant increases in the number of synapses in layer V of isolated cortical strips at 30 days correlated with significant decreases in the time delay, while decreases in the number of synapses at 90 days correlated with a significant increase in the time delay.

Effects of temperature on the spike activity of cortical neurons in guinea pigs.

Studies on parietal cortex slices from guinea pigs showed that a decrease in temperature from 37 degrees C to 24 degrees C significantly decreased the level of spontaneous neuron activity, while activatory reactions to iontophoretic administration of glutamate showed no significant change.

[Temperature sensitivity of the cholinergic response in cortical neurons of guinea pigs].

A temperature change from 20 to 36 degrees C results in a significant increase of neuronal responses to iontophoretic application of acetylcholine in parietal cortex slices. The most intensive changes in cholinergic responses occurred in two temperature zones: 27-29 degrees C and 34-36 degrees C. Increase in the responses to acetylcholine accompany with increasing spontaneous spike activity.

[Effect of temperature on impulse activity of cortical neurons in guinea pigs].

The temperature change of incubating fluid from 37 to 24 degrees C results in significant decrease of neuronal spontaneous firing rate in parietal cortex slices. Evoked spike responses to microiontophoretic application of glutamate practically did not change.