bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of K+ accumulation removal and high extracellular osmolarity on K+ current in insect axonal membrane
Authors: Stankiewicz Maria , Pelhate Marcel , Pancerzyńska Izabela , Zienkiewicz Andrzej , Kądziela Wojciech
Published: December 2023

The effect of a removal of K+ accumulation on K+ current in insect axonal membrane was observed. Experiments were performed on isolated giant axon of a cockroach using double oil gap technique. K+ accumulation was reduced by: (l) an outward water flow induced by non-electrolytes (urea, glucose) added to extracellular saline and (2) by an increase of non-specific permeability of axonal glial layer obtained after the application of DMSO. The conclusions are: (1) osmolar effect depends on the type of molecule used for osmotic shock, (2) increase of outward K+ current in conditions of high extraaxonal osmotic pressure is attributed to the decrease of K+ accumulation and outward water flow, (3) removal of K+ accumulation doesn't affect the kinetics and the time course of K+ current, (4) experiments confirmed the presence of an inactivating component in the axonal outward K+ current, (5) DMSO must be used cautiously as a solvent in electrophysiological experiments.
Brainstem neurones and postganglionic sympathetic nerves: does correlation mean connection?
Authors: McAllen Robin , May Clive
Published: December 2023

Short-term correlations in activity have been widely used as evidence to connect brainstem units with postganglionic sympathetic nerves. These may be detected by spike-triggered averaging, cross correlation or coherence analysis. The specificity of this type of evidence has been investigated by cross-correlating the activity of identified cutaneous vasoconstrictor postganglionic fibres with that of medullary premotor neurones of like and of unlike functional type, as determined by physiological testing (preoptic warming), in anaesthetised cats. Single medullary premotor neurones of both types were recorded from the subretrofacial nucleus: they were identified by their barosensitivity and, in most cases, their spinally projecting axons. By the test criteria chosen, the correlation method gave both false-positive and false-negative results as commonly as it gave correct ones. We conclude that it is not a reliable way to determine brainstem-postganglionic connectivity.
The value of magnetic resonance imaging in diagnosis and monitoring of treatment in multiple sclerosis
Authors: Bekiesińska-Figatowska Monika , Walecki Jerzy , Stelmasiak Zbigniew
Published: December 2023

We analysed MR examinations of 277 patients with multiple sclerosis. White matter hyperintensities in brain were found in 270 of them. The most frequently they were found in periventricular white matter (in 100% of cases), in subcortical localization (52.2%) and in the corpus callosum (44.4%). MR examination allows to estimate the activity of the disease on the basis of the presence of oedema around the plaques and their contrast enhancement with gadopentetate dimeglumine (Gd-DTPA). 17.8% of all cases showed the signs of the acute phase of MS. About one-third of all cases were accompanied by cortical brain atrophy (the most often seen in the frontal lobes), subcortical brain atrophy was less frequent (one-sixth). In about two-third of all cases the corpus callosum atrophy was found. The analysis of follow-up MR examinations of 83 patients taking part in a double-blind placebo-controlled trial of a new immunosupressive drug cladribine showed that patients from the placebo group were more compliant to any changes of the plaques. Decrease of the plaques size was found mainly in women. No correlation between the patients age and the plaques changes was established.
Effect of lateral hypothalamic lesion on sleep-waking pattern and EEG power spectra in the rat
Authors: Jurkowlaniec Edyta , Pracki Tadeusz , Trojniar Weronika , Tokarski Juliusz
Published: December 2023

Bilateral, electrolytic lesion of the lateral hypothalamus (LH) in rats produces hyposomnia and qualitative EEG changes which are difficult to assess by conventional visual inspections of electroencephalograms. In the present study the spectral analysis of EEG was applied in LH-lesioned rats and confronted with a standard visual scoring method. One-hour samples of hippocampal and cortical EEG were taken from the light part of the circadian cycle before and after electrolytic or sham LH damage. In half of the LH-lesioned rats a power spectral analysis was performed using a Fast Fourier Transform routine at 1 Hz bands from 0.5 to 25 Hz; in the other half, as well as in the sham-lesioned group, EEG records were visually scored for the amount of waking, slow wave sleep and paradoxical sleep. Significant hyposomnia effects were found in LH-lesioned rats. Power spectral analysis of hippocampal EEG revealed a significant increase in power density at 4–6 Hz and a reduction at 7–10, 14–17, 19–22 and 23–24 Hz. In neocortical EEG there was a significant increase in power density at 5–6 Hz band and a reduction at 7–8 Hz. The results are discussed in the context of the effects of selective destruction of the specific neurotransmitter systems occupying the LH area.
Functional connections between the pineal gland and immune system
Authors: Skwarło-Sońta Krystyna
Published: December 2023

Experimental findings which support a functional connection between the pineal gland and immune system in mammals and birds are summarized. Developmental and age-related changes in pineal gland function appear, at least partially, to be related with immune system efficiency. Mechanisms whereby melatonin influences immune system function are complex, but include participation of mediators (endogenous opioids, cytokines, hormones, zinc pool) as well as specific binding sites on the immune cells. Melatonin, as a highly lypophilic compound, may also penetrate immune cells without mediation of specific receptors and act within as a potent free radical scavenger and as an anti-aging and oncostatic factor. The immune system may, in turn, via synthesis and secretion of soluble factors, cytokines, influence pineal gland function, thereby closing the information loop to maintain homeostasis in order to face the harmful environment.
Melatonin as a chronobiotic: PROS and CONS
Authors: Steinlechner Stephan
Published: December 2023

The pineal gland is a major component in the regulation of photoperiodic responses and hence, saisonality. All functions which appear to be controlled by the day length can be influenced by modifying the output signal of the pineal gland, i.e. melatonin. An important property of the melatonin signal is that the duration of melatonin synthesis and release varies proportionally with the length of the night suggesting that the duration of elevated melatonin is the most important signal conveying the photoperiodic message. In addition to the temporal coordination of saisonal phenomena, melatonin appears to be involved in the control of circadian rhythms in mammals. Activity-rest cycles of rats can be entrained by infusion or injection of melatonin at appropriate times of the daily cycle. Rhythms of neuronal activity of the suprachiasmatic nuclei (SCN) of the hypothalamus can be inhibited and phase-shifted by application of melatonin. The firing rate of SCN neurones of rats can be inhibited by iontophoretic application of melatonin. These data are in good agreement with the high density of melatonin receptors found in the SCN of most – but not all- mammalian species. On the other hand, activity-rest cycles appear to be perfectly normal in animals which lack a daily melatonin rhythm. This, however, might be a laboratory artefact, and this system will probably fail when challenged in a complex situation.
Preliminary process theory: towards an integrated account of the psychophysiology of cognitive processes
Authors: Barry Robert
Published: December 2023

A brief overview of the history of the orienting reflex (OR) in western psychology is presented, in order to provide a context for a discussion of its role in attentional processing. Some aspects of observed response fractionation are discussed, leading to an outline of a coherent theory of preliminary processes in OR elicitation. This discriminates between involuntary and voluntary aspects of cognitive processing but depends on a common core mechanism. The role of state variables in modulating phasic responses is also discussed. Although this theory was developed largely from a study of autonomic responses, it has been possible to extend it to include various central measures, and recent extensions are described. A number of recent studies are briefly outlined to provide examples demonstrating the use of a range of physiological measures (central and peripheral) in a variety of situations (from the pistol range to the laboratory) with different subject groups (adults, children and psychiatric patients). Finally, the use of heart rate data in the investigation of task-relevant cognitive load is discussed as a relatively simple but sensitive index to explore drug and other effects in cognition. These examples indicate the wide-ranging potential benefits of using psychophysiological approaches in the study of cognitive processes.
Acute hypoxia modulates arachidonic acid metabolism in cat carotid bodies. Role of dopamine
Authors: Strosznajder Robert
Published: December 2023

The hypoxic stimulus of the arterial blood is transformed at the carotid body (CB) chemoreceptors into neuronal signals regulating respiration. The mechanism of chemotransduction is until now not well understood. In this study the regulation of arachidonic acid (AA) release and its incorporation into membrane glycerolipids were investigated. Moreover, the effect of hypoxia and dopamine (DA) on these processes was evaluated. The CB were excised from cats exposed in situ to normoxia or hypoxia. Then CB were homogenized and used as a source of enzyme (s). It was observed that Ca2+ enhanced the release of AA by 40–50% through the action of phospholipase C together with diacyl-glycerollipase and phospholipase A2. Acute hypoxia significantly decreased AA incorporation into phosphatidylinositol (PtdIns) and enhanced the level of AA radioactivity in diacylglycerol and AA-CoA. These results suggest that hypoxia induces inhibition of AA incorporation on the level of acyl-CoA-lysophospholipid:acylotransferases. DA decreased AA incorporation into PtdIns and exerted an additive inhibitory effect in hypoxic samples. These results demonstrate that AA metabolism in CB is significantly affected by hypoxia and that DA is not responsible for the hypoxia-induced alteration of lipid metabolism in CB.
How does trimethyltin affect the brain: facts and hypotheses
Authors: Koczyk Danuta
Published: December 2023

Trimethyltin, an organic compound of tin, is a potent neurotoxic ant of a mechanism of action yet to be uncovered. The neuropathological findings that trimethyltin causes selective hippocampal damage with several unique features, highly reminiscent of Ammon's horn sclerosis as a final result, have raised the possibility that there is a link between trimethyltin neurotoxicity and other degenerative events for which an imbalance between neuronal inhibition/excitation has been proposed. However, there still exists a whole catalog of issues which await clarification. One of the greatest importance is how does trimethyltin reach the critical sites within the brain and what are they? Available data concerning the long-term consequences related to trimethyltin neurotoxicity are also far from being completed. This review summarizes current data from in vitro and in vivo studies on neurotoxic effects of trimethyltin. Several hypotheses on mechanisms that may lead to neuronal death induced by the toxin are presented.
Carnitine - a known compound, a novel function in neural cells
Authors: Nałęcz Katarzyna , Nałęcz Maciej
Published: December 2023

Carnitine (4-N-trimethylammonium-3-hydroxybutyric acid) seems to fulfill in the brain a different role than in peripheral tissues. Carnitine is accumulated by neural cells in a sodium-dependent way. The existence of a novel transporter in plasma membrane, specific to compounds with a polar group in the B-position with respect to carboxyl group, has been postulated. The presence of a carnitine carrier in the inner mitochondrial membrane has been proven and the protein has been purified. It is postulated that its major role in adult brain would be translocation of acetyl moieties from mitochondria into the cytoplasm for acetylcholine synthesis. The latter process is stimulated by carnitine and choline in a synergistic way in cells utilizing glucose as the main energetic substrate. Carnitine metabolism in neural cells leads to accumulation of different acyl derivatives of carnitine. Palmitoylcarnitine can influence directly the activity of protein kinase C. An involvement of carnitine in a decrease of palmitate pool used for palmitoylation of regulatory proteins has been postulated.
Concanavalin A enhances quisqualate-induced calcium influx in cerebellar granule cells in culture
Authors: Danysz Wojciech , Raulli Robert , Wroblewski Jarda
Published: December 2023

In primary cultures of cerebellar granule cells kainate produced marked influx of 45Ca2+, partially sensitive to the N-methyl-D-aspartate (NMDA) antagonist, 3-(+/-)-2-carboxypiperazin-4-yl)- propyl-1-phosphonic acid (CPP), indicating involvement of an NMDA receptor-sensitive component that may be secondary to kainate-induced glutamate release. Sodium removal partially inhibited kainate's effect. Quisqualate also produced influx of 45Ca2+, but with lower efficacy and higher potency than kainate. This action of quisqualate was unaffected by CPP and by sodium removal. Preincubation of cells with the plant lectin concanavalin A (Con A), but not with its succinyl derivative, enhanced quisqualate-induced calcium influx, and to a lesser extent kainate's effect. Inclusion of quisqualate in preincubation medium antagonized Con A potentiation of quisqualate response. Also Con A was ineffective when included in the incubation medium only, without preincubation. Preincubation of rat brain cortical membranes with Con A but not with succinyl Con A increased the binding of the AMP A receptor agonist, [3H]alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid ([3H]AMPA). The results suggest that Con A enhancement of quisqualate response possibly involves the modification of an AMPA recognition site and requires preincubation in the absence of an agonist (here quisqualate).
Electrical activity of the acutely isolated pons in cats
Authors: Dec Krystyna , Stasiak Maciej , Waleszczyk Wioletta , Żernicki Bogusław
Published: December 2023

The cat's pons was isolated by two brain stem transections, at the junction of medulla and pons and at the junction of pons and midbrain. In the deafferented pons the EEG activity was virtually absent, whereas the spatial density of active units and the rate of their spontaneous spike activity were at a high level. In the pons of control preparations with brain stem transected only at the ponto-midbrain junction the EEG activity was present, while the single-unit activity was such as in the isolated pons. The electrical activity of the isolated pons was similar to that previously described in the cat's isolated midbrain. The discrepancy between EEG and single-unit activity suggests that in the deafferented pons or midbrain many neurones are asynchronously autoactive. Also, these results show that a flat EEG record is not necessarily a sign of absence of the neural activity and neural death.
The presence of histamine and tele-methylhistamine in the pineal gland of chick
Authors: Zawilska Jolanta , Sęk Agata , Orszulak-Michalak Daria , Mackova Martina , Nowak Jerzy
Published: December 2023

The levels of histamine (HA) and tele-methylhistamine (t-MeHA) in chick pineal gland were measured by RIA at two time points, i.e. at the end of the light (L) phase and in the middle of the dark (D) phase of 12 h: 12 h L:D cycle. The chick pineal gland showed high HA levels (12.19 and 13.09 ng/pineal at Land D, respectively). The t-MeHA content of chick pineal gland was about 20-times lower than HA level (650.2 and 536.4 pg/pineal at L and D, respectively). An amino acid precursor of HA, L-histidine (1 g/kg, ip), given to chicks during L or D significantly increased both HA and t-MeHA content of the pineal gland. The L-histidine-evoked elevations in HA level were 2–4-times higher than changes in t-MeHA content. Enzymatic study showed the presence in chick pineal of a moderate activity of L-histidine decarboxylase (HDC), and well expressed activity of HA-methyltransferase (HMT), HA synthesizing and inactivating enzyme, respectively, which suggests that both HA and t-MeHA may be produced within the gland. It is suggested that the metabolic dynamics of the pineal HA may be higher during lighthours than darkhours of the daily light dark illumination cycle.
Apparatus for studying behavior and learning in restrained rats
Authors: Soltysik Stefan , Jackson Richard , Jeleń Piotr
Published: December 2023

A new treadmill/stand apparatus for a rat is described. It will be useful in behavioral experiments when control of the animal's position in the training chamber is required while considerable freedom of movement, including locomotion, is desired. The position and distance relative to sources of stimuli are thus kept constant. The speed and the distance of ambulation are easily monitored. The rats are sufficiently restrained to enable easy recording of various measures such as EKG, EMG or EEG, etc. Classical and instrumental conditioning procedures are easily implemented. An example of the data from acquisition training during Pavlovian conditioning is shown (diaphragm EMG, heart rate (HR), locomotion and vocalization).
Melatonin as a chemical indicator of environmental light-dark cycle
Authors: Zawilska Jolanta
Published: December 2023

Melatonin (N-acetyl-5-methoxytryptamine) is an evolutionary highly conserved molecule that plays an important role in conveying the clock and calendar information to all living organisms, including man. Melatonin is synthesized in the rhythmic fashion, primarily by the pineal gland, and, to a lesser degree, by extrapineal tissues – namely the retina, the Harderian gland, and the gastrointestinal tract. The rhythm of the hormone production, with maximal levels occurring at night in darkness, is generated by an endogenous circadian clock(s) and is synchronized with the photoperiodic environment to which animals are exposed. This brief outline surveys data on the regulation of rhythmic melatonin biosynthesis by a circadian pacemaker and light (full spectrum white light and monochromatic lights with wavelengths both in the visible and invisible range). Additionally, possible applications of this chronobiotic compound in agriculture and in medicine in the treatment of circadian rhythm sleep disorders are discussed.
Effects of melatonin infused into the III ventricle on prolactin, beta-endorphin and luteotropin secretion in ewes during the different stages of the reproductive cycle
Authors: Misztal Tomasz , Romanowicz Katarzyna , Barcikowski Bernard
Published: December 2023

Secretion of all the pituitary hormones undergoes marked circadian and seasonal changes. The rhythmicity of these changes is controled by the circadian pacemaker system and the pineal gland transmitting daylength information to the neuroendocrine axis via the secretion of melatonin. This article presents data on the effects of the short-term melatonin administration into the third brain ventricle on prolactin, beta-endorphin and luteotropin secretion in ewes kept under the increasing and decreasing daylength conditions. Additional emphasis is given to dopamine and LHRH release in the mediobasal hypothalamus under the melatonin treatment by the push-pull method. The long-term and short-term actions of melatonin on the hormonal status in ewes is also discused.
Effects of growth hormone on neuroendocrine function
Authors: Bartke Andrzej , Chandrashekar Varadaraj , Steger Richard
Published: December 2023

Although the role of growth hormone (GH) in the control of reproductive functions is not well understood, there is considerable evidence that the states of both GH deficiency and GH excess are typically associated with reproductive deficits. To identify the possible involvement of functional alterations in the hypothalamic-pituitary system in producing these deficits, we are studying neuroendocrine function related to reproduction in transgenic animals overexpressing GH, in animals with congenital GH deficiency, and in animals with selective immunoneutralization of GH. The results indicate that GH acts on the hypothalamus to alter dopaminergic and noradrenergic control of prolactin and gonadotropin release. Life-long elevation of GH levels outside the physiological range disrupts feedback control of luteinizing hormone (LH) release by gonadal streroids. Plasma LH and follicle-stimulating hormone (FSH) levels and feedback control of LH release are also abnormal in GH-deficient animals indicating that physiological levels of endogenous GH are normally involved in the control of gonadotropin release. Differences between the effects of bovine vs. human GH in transgenic mice and differential effects of GH deficiency in mice and rats should facilitate identification of the mechanisms involved in the actions of GH on the hypothalamic-pituitary system.
Sex and strain differences of acoustic startle reaction development in adolescent albino Wistar and hooded rats
Authors: Błaszczyk Janusz , Tajchert Katarzyna
Published: December 2023

Acoustic startle responses (ASR) were studied in 12 young Wistar albino and in 15 hooded rats of both genders. The six week old animals were first exposed to a 6.9 kHz tone pair of 2 ms pulses of 120 db intensity with the inter-stimulus interval (ISI) between 2 and 11 ms. ASR amplitudes and latencies as a function of the ISI, animal strain and gender were recorded and analyzed for ten consecutive weeks. No differences in the ASR amplitude between Wistar and hooded rats were found. ASR amplitude increased during the experimental period and followed body weight increase. Significant differences were also observed between male and female rats in their startle responses to acoustic stimuli. Generally, male subjects responded with a greater ASR amplitude than females, and the changes may be attributed to the difference in neuromuscular development between genders. This experiment sets a background for further developmental studies.
Nonlinearities within the cat LGN cell receptive fields in simulated network with recurrent inhibition
Authors: Musiał Paweł , Panecki Stanisław , Gerstein George , Wróbel Andrzej
Published: December 2023

We investigated the receptive fields of principal cells from the cat's lateral geniculate nucleus cells. About 20% of the X type neurones showed clear nonlinearities of summation when stimulated by two simultaneously onset, small bars of light. The possible source of this nonlinearity was studied on a specially designed model of a one-layer neuronal network with inhibitory, recurrent interactions, intended to mimic the inhibitory influence exerted on geniculate relay cells by perigeniculate interneurones. The model, when activated from periphery by two stimuli-like input patterns, produced at the output side the nonsymmetrical profiles of the receptive fields sensitivity, similar to those obtained in real experiments. This nonlinear output appeared when some of the relay cells were inhibited below their firing level threshold and this effect was spread through the network by lateral inhibitory connections. It is concluded that physiologically observed nonlinearities of the order of single receptive field mechanisms can be predicted by a simple recurrent network.
Naloxone impairs spatial performance in rats
Authors: Łukaszewska Irena
Published: December 2023

Naloxone-injected (l.0 mg/kg) and saline-injected control rats were subjected to a two-trial test of object localization memory. In trial I rats were allowed to explore for 5 min an enclosed T-maze with an object (plastic bottle) placed in one maze arm. Then, the object was removed and after a 20-min retention interval rats were faced with two empty arms of the same maze (trial II). Control rats showed good retention of the place occupied by the object, displaying a significant preference (74%, P
A simple, non-invasive method for the measurement of reserpine­-induced tremor in rats
Authors: Meert Theo , Rombouts Jef , Voeten Jan , Naranji Farajollah , Clincke Gilbert
Published: December 2023

A new, non-invasive method for measuring reserpine-induced tremor in rodents is described here. The test procedure is based on the piezo-electric principle and was evaluated using the tremorogenic compound reserpine and the stereotypies-inducing drug apomorphine. Whereas for reserpine an orderly and dose-related increase in activity was observed, no such effect was detected with apomorphine. In order to further evaluate the test procedure, studies on the antagonism of reserpine- induced tremor were also performed. Results from these studies indicated that the DA-agonist lisuride, but not the S2-antagonist ritanserin, were able to antagonize the reserpine-induced tremor in a dose-related manner.
The effect of corticotropin-releasing factor (CRF) on the gonadotropin hormone releasing hormone (GnRH) hypothalamic neuronal system during preovulatory period in the ewe
Authors: Polkowska Jolanta , Przekop Franciszek
Published: December 2023

Effects of infusions of corticotropin releasing factor (CRF) into the 3rd ventricle of the brain of ewes during the proestrus on the immunoreactive (ir) gonadotropin hormone releasing hormone (GnRH) neuronal system, pituitary luteinizing hormone(LH) producing cells and LH concentrations in the blood plasma were studied. None of the CRF-treated sheep displayed the estrous activity nor ovulated on the day of estrus (17th day of the cycle), and two days later when they were slaughtered. The GnRH center of CRF treated ewes situated in the preoptico-septal area was well organized, but irGnRH stores in the median eminence were low in comparison to the controls (sheep from the late follicular phase of the estrous cycle). The feature and the number of LH-cells in CRF-treated ewes were typical for the preovulatory phase of the cycle but the plasma concentrations of LH did not exceed basal levels. These results suggest that CRF induced decrease of irGnRH stores in the nerve terminals of the ME can be responsible for the blockade of the preovulatory surge of GnRH/LH in the sheep.
Spike-wave discharges and sleep spindles in rats
Authors: Luijtelaar Egidius
Published: December 2023

Sleep spindles and spike-wave discharges are thought to originate from the same thalamic pacemaker. In the present work it is investigated whether sleep spindles and spike-wave discharges are also sensitive for the same drugs. Adult male WAG/Rij rats were chronically implanted with frontal and occipital EEG electrode pairs. Rats were intraperitoneally injected with clonidine (0.00625 mg/kg), phenobarbital (20 mg/kg), flunitrazepam (0.188 mg/kg). Frontal and occipital sleep spindles and mainly frontal spike-wave discharges were seen in the electroencephalogram. Phenobarbital and flunitrazepam reduced the number of spike-wave discharges and enhanced frontal sleep spindles, while clonidine facilitated spike-wave discharges and reduced frontal sleep spindles. The results of these three drugs indicate a reciprocal relationship between the number of frontal sleep spindles and the number of spike-wave discharges. Only clonidine facilitated occipital sleep spindles without an effect on spike-wave discharges. It can be concluded that frontal and occipital sleep spindles have a different pharmacological profile. Furthermore, the inverse relationship between frontal sleep spindles and spike-wave discharges may suggest that sleep spindles and spike-wave discharges are controlled by a single controlling system. However, in order to explain the clonidine data on occipital sleep spindles another factor must be incorporated in properties of the mechanism(s) involved in EEG oscillations.
The effect of naloxone on object exploration, object recognition and other types of spontaneous behavior
Authors: Łukaszewska Irena , Klepaczewska Anita
Published: December 2023

Object exploration was examined in naloxone injected (l mg/kg or 4 mg/kg) and saline control rats. Naloxone rats explored an object for a shorter time than did controls, thus indicating a lower investigatory motivation. This effect was dose dependent. Higher drug dose (4 mg/kg) decreased the number of contacts with an object. Both doses increased the mean duration of contacts with an object. The naloxone groups showed intact recognition of a familiar object paired with a new one in two sessions – 4 h and 24 h after the injections. The higher drug dose depressed the locomotor activity and wall leaning. Grooming was not influenced by naloxone. The normal daily fluctuations in the level of grooming and locomotion were distorted following the injection of the higher dose of naloxone. The lower dose (l mg/kg) did not affect the rats' performance in some tests. The results could be viewed as a naloxone-related depression of the behavior containing motor elements like locomotion, wall leaning and object approaching. The prolonged contact time with an object could be the result of a lowered flexibility of movement. However, the decrease of rewarding value of exploration could not be ruled out. Possibly, naloxone exerts several different interacting behavioral effects.
Thalamic and amygdaloid connections of the auditory association cortex of the superior temporal gyrus in rhesus monkey (Macaca mulatta)
Authors: Kosmal Anna , Malinowska Monika , Kowalska Danuta
Published: December 2023

Thalamic and amygdaloid connections of three association auditory areas (AA1, AA2, AA3) of the superior temporal gyrus (STG) were investigated. In order to define the projections of the particular areas, injections of fluorescent tracers were made in three monkeys. Distribution of labeling indicates that area AA1 differs from areas AA2 and AA3 in patterns of both thalamo-cortical and amygdalo-cortical connections. Area AA1 receives its predominant inputs from the ventral and dorsal nuclei of the medial geniculate body (MGB). The amygdaloid projection to the area AA1 originates from the basal nuclei, whereas input from the lateral nucleus was not found. The characteristic thalamic projections to areas AA2 and AA3 originate from the dorsal MGB nucleus and the polymodal nuclei of the posterior thalamus. The density of projections from the dorsal nucleus gradually decreases from area AA1 to area AA3 while projections from the Plm, Sg and Lim nuclei increase in the same direction. Areas AA2 and AA3 are the source of strong connections with the lateral nucleus of amygdala, which density increases progressively when injections shift from area AA2 to AA3. The basal and accessory basal nuclei are the source of a less significant amygdalofugal projections to both cortical areas. Thus, our experimental data indicate that influence of the polymodal thalamic nuclei increases substantially in the direction of the higher order association areas. The strong relation of the same cortical areas with the lateral amygdaloid nucleus might suggest that areas AA2 and AA3, in addition to auditory input are the site of transfer of complex sensory information to the amygdala.
Photochemically-induced vascular damage in brain cortex. Transmission and scanning electron microscopy study
Authors: Gajkowska Barbara , Frontczak-Baniewicz Małgorzata , Gadamsk Roman , Barskov Igor
Published: December 2023

Morphological changes of microvessels of cerebral cortex were evaluated in a model of cerebral infarction initiated by a photochemical reaction. Rats were treated with intravenous injection of rose Bengal and irradiated from a halogen lamp source through an intact cranium to precipitate microvascular damage. Investigations in transmission and scanning electron microscopy revealed platelet aggregation on endothelial cells preceded by its early ultrastructural damage. Other typical microscopic features of brain ischaemic injury were present suggesting that the present method may be used as a model for investigating ischaemic brain damage. Since the photochemical activation of the rose Bengal dye results in formation of reactive oxygen species this model may be particularly useful to elucidate the role of free radical-mediated endothelial damage in the formation of microthrombi and blood-brain-barrier integrity.
Diversity of connections of the temporal neocortex with amygdaloid nuclei in the dog (Canis familiaris)
Authors: Kosmal Anna , Malinowska Monika , Woźnicka Agnieszka
Published: December 2023

Reciprocal connections of amygdaloid nuclei with the temporal neocortex in the dog were investigated. Injections of fluorescent tracers and BDA into particular temporal areas were made in eleven dogs. The topographical arrangement of connections and variations in their density differentiate the temporal neocortex in the dog into a few regions. Among them, the cortex involving the anterior part of the ectosylvian gyrus did not send any amygdalopetal projection. The middle ectosylvian, dorsal zone of the posterior ectosylvian and the anterior part of the Sylvian gyrus were weakly connected with the amygdala. The cortical region involving the ventral zone of the posterior ectosylvian and composite posterior areas, as well as posterior Sylvian gyrus, was characterized by profuse connections with the amygdaloid complex. Cortico-amygdaloid connections originate in the wide cortical area of the auditory cortex of the middle and dorsal part of the posterior ectosylvian gyrus as well as in the auditory association cortex located in the ventral ectosylvian, composite posterior and posterior Sylvian gyri. The connections showed a dorso- ventral gradient of increasing density, in the direction of association fields. The most substantial projection taking rise from the ectosylvian posterior and posterior composite gyri terminated preferentially in the pericapsular sector of the lateral amygdaloid nucleus and, to a lesser degree, in its medial sector. Terminals of connections originating in the Sylvian gyrus occupied preferentially the intermediate part of the lateral nucleus, slightly more medially than that from the ectosylvian and posterior composite areas. Additionally, axonal terminals derived from the composite posterior and Sylvian posterior areas were observed in the basal parvocellular and magnocellular nuclei. Neocortical projections were reciprocated by amygdalofugal connections with two exceptions: the basal magnocellular nucleus was distinguished by a substantial amygdalofugal projection to the temporal neocortex focused on the dorsal Sylvian gyrus, and the central nucleus of the amygdala, in contrast, received an exclusively corticofugal projection.
Phosphorylation of 68 kDa neurofilament proteins has no significant effect on their assembly
Authors: Šonská Alice , Entlicher Gustav
Published: December 2023

Native low molecular weight neurofilaments (NF-L) from bovine spinal cord with original phosphate content of 0.4 moles of phosphate per 1 mol of protein were phosphorylated with cyclic AMP dependent protein kinase and protein kinase C. In a similar way recombinant mouse NF-L proteins which did not contain any phosphate were phosphorylated with the same enzymes in both, the assembled and disassembled forms. The final phosphate content in both types of NF-L proteins reached about 4 moles of phosphate per 1 mol of protein. This phosphorylation had no effect on the assembly of NF-L into filaments as observed by electron microscopy.
The method of training dogs in auditory recognition memory tasks with trial-unique stimuli
Authors: Kowalska Danuta
Published: December 2023

Three adults dogs were trained in a auditory recognition delayed-matching-to-sample (DMS) task. The experimental setting consisted of one central speaker located in front of the dogs head, two side speakers with nearby response pedals and one rotary food delivery system. Three hundred twenty natural sounds were used as trial-unique stimuli. Sample stimuli were always given through the central speaker. After the delay of 1.5 s, both sample and testing stimuli were activated alternately through the two side speakers. Bar-press response toward the sample stimulus was rewarded by food. The DMS training was continued until attaining a criterion 90% correct responses in 90 consecutive trials. After a control pause, the dogs were retrained to the criterion, and then they were given performance tasks with delays extended to 10-, 30-, 60- and finally to 90-s, in blocks of 90 trials. Dogs required about 1,000 trials of auditory recognition memory training in order to reach the criterion. Their behavior was also stable after the control pause. The dogs performance declined gradually with extended delays reaching an average of 63.4% for the delay of 90 s. Results indicate that the DMS task with auditory stimuli alternating during the testing stage of trial, is a promising method for testing auditory recognition memory.
Aging and beta-amyloid peptides decrease cholinergic receptor-mediated calcium increase in brain cortex synaptoneurosomes
Authors: Samochocki Marek
Published: December 2023

In this study, the muscarinic cholinergic receptor (MAChR)-evoked inositol 1,4,5-trisphosphate (IP3)-mediated increase of cytosolic calcium concentration ([Ca]i) in synaptoneurosomes from brain cortex of adult and aged rats was investigated. In addition, the effect of two beta-amyloid (Abeta) peptides, 1-28 and 25-35, on the resting and MAChR-induced increase of [Ca]i in brain cortex synaptoneurosomes of adult rats was evaluated. Release of IP3 was measured after prelabeling of synaptoneurosomal phosphoinositides with myo-[2-3H]inositol. Changes in [Ca]i were monitored by using fura-2 indicator. The effect of Abeta peptides was evaluated following their preincubation with synaptoneurosomal protein for 1, 5, 30 and 60 min. It was observed that in brain cortex synaptoneurosomes from aged rats, Ca2+-dependent and MAChR-mediated IP3 production was not changed in comparison with that estimated in adult brain, over 60 min of incubation. Activation of MAChR in synaptoneurosomes from brain cortex of adult rats for 10 min increased [Ca]i by about 60% over its resting level (240 nM). This increase was completely blocked by muscarinic antagonists, atropine and pirenzepine, as well as by the antagonist of IP3 receptor, 8-(diethylamino)-octyl-3,4,5-trimethoxybenzoate (TMB-8). In aged brain, there was no detectable change in resting [Ca]i (165 nM) due to MAChR stimulation. The 25-35 Abeta peptide caused a time-dependent significant increase of resting [Ca]i in synaptoneurosomes from brain cortex of adult rats, which was almost five-fold after 60 min. In the same conditions, the action of 1-28 Abeta peptide was statistically insignificant up to 30 min, then a rapid increase of resting [Ca]i by two-fold was observed up to 60 min. Both A~ peptides decreased markedly the MAChR-dependent elevation of [Ca]i in respect to control (resting [Ca]i) in synaptoneurosomes from brain cortex of adult rats. These results indicate that beta-amyloid 1-28 and 25-35 peptides may be involved in alteration of muscarinic receptor-mediated signal transduction during brain aging.
The effect of tonic pain on processing the non-painful stimuli indexed by late components of event-related potentials
Authors: Michalski Andrzej
Published: December 2023

Event-related potentials (ERPs) evoked by light flashes and auditory tones in a standard odd-ball procedure were recorded from Fz, Cz and Pz scalp sites. Tonic pain was evoked by immersion of the hand in cold water (5 degrees Celsius). Significant effects of pain were found in responses to target stimuli but not in responses to non-target stimuli. P300 wave was affected more than the earlier P200 component. The reduction of P300 amplitude was the strongest effect, both in auditory and visual tests. P300 latency was not significantly affected. Difference curves (target minus non-target ERPs) showed the additional effects: latency of P200 component was elongated and its amplitude enlarged but only in auditory experiments. In control experiments with warm water stimulation no significant alterations of P300 or P200 components were found. The results show that the effect of tonic pain is specific: it predominantly affects the processes that manifest themselves as amplitude changes of P300 components in responses to target stimuli.
Effects of caffeine on NMDA-evoked 45Ca2+ release in the rat dentate gyrus in vivo
Authors: Alaraj Mohd , Kosińska Irena , Łazarewicz Jerzy
Published: December 2023

Caffeine in 10(-2) M concentration per se activates ryanodine receptors (RyR) in vitro, thereby increasing the intracellular concentration of Ca2+ ([Ca2+]i). In general opinion, caffeine applied in vivo in much lower doses does not affect [Ca2+]i in neurones. However, it was recently demonstrated that caffeine in low concentrations in vitro potentiates evoked Ca2+ release in neurones via RyR. Microdialysis of the rat dentate gyrus (DG), combined with measurement of 45Ca2+ efflux, has been used in our laboratory to study in vivo NMDA-evoked calcium induced calcium release (CICR) via RyR. The aim of the present microdialysis study was to investigate in vivo effects of caffeine, applied systemically in a pharmacologically-relevant dose, and locally in the dialysis medium in very high concentration, on the NMDA-evoked CICR in DG neurones. To ensure steady brain concentration of caffeine, its systemic (i.p.) administration in a dose of 40 mg/kg was followed by a continuous i.p. infusion of 80 micropgrams/kg/min and application of 0.4 mM caffeine in the dialysis medium. The results demonstrated that in the rat DG, local administration of 50 mM caffeine significantly stimulates a spontaneous 45Ca2+ efflux and its release induced by 5 mM NMDA. However, systemic administration of caffeine had no effect on spontaneous and NMDA-induced 45Ca2+ release in the rat DG, which supports the view that caffeine, applied in vivo, even in high doses, does not influence CICR in brain neurones.
Differential effects of non-REM and REM sleep on sensory gating in rats
Authors: Luijtelaar Egidius , Miller Christopher , Coenen Anton , Drinkenburg Wilhelmus , Ellenbroek Bart
Published: December 2023

Sensory gating in rats can be measured with a double click paradigm. The diminished response towards the second click is a physiological manifestation of reduced sensory input. This physiological process seems to be disturbed in human psychoses. It is thought that gating, as measured with this paradigm, is a preattentive, involuntary phenomenon which is not modulated by attention. If this is indeed the case, than it is hypothesized that gating should not be modulated by non-REM sleep. In the present experiment pairs of clicks (500 ms interval) were presented during wakefulness, non-REM as well as REM sleep and cortical auditory evoked potentials (AEP's) were recorded in chronically implanted rats. Rather similar AEP's were found after the first and second stimulus. However, the amplitudes of the various components of the second AEP were smaller than those of the first AEP, suggesting a gated response. This was the case during all three levels of vigilance. The amplitudes of both AEP's showed the more often reported changes in amplitude during sleep and REM sleep. Clear differences were seen in gating: compared to wakefulness a decrease in gating was found during REM sleep while gating was unchanged during non-REM sleep. The latter outcome seems to confirm that gating in rats is indeed a preattentive process. Finally, results were discussed in terms of neuronal properties of thalamic relay cells and it is suggested that firing properties of thalamic relay cells are not involved in this type of sensory gating.
Clock-spiking cells not only in the eye of the fly, but also in the antenna!
Authors: Moro Sulochana , Huotari Matti
Published: December 2023

During the course of single cell olfactory recordings from the funicular part of the antenna of Drosophila virilis we encountered a pair of cells firing synchronously and consistently at a rate of about 9 to 14 spikes per second. Every spike was seen to consist of a spike complex made up of two separate biphasic components thought to originate from two separate cells. The larger action potential, appearing first, had a peak-to-peak (ptp) amplitude of up to 200 microV followed closely by a smaller spike with an amplitude of about 60 microV. The repetitive firing pattern was not affected by air or odour puffs. This kind of consistent spontaneous spiking activity of two closely associated cells resembles remarkably closely the clock-spikes hitherto known only from the eyes of flies. Our encounter with such cells in a sense organ other than the eye poses many new questions and could lead to a renewed effort to understand the role(s) of the clock -spiking cells as possible oscillatory components of the dipteran pacemaking system in particular and the insect nervous systems, generally.
Experience-dependent changes in vibrissae evoked responses in the rodent barrel cortex
Authors: Glazewski Stanislaw
Published: December 2023

A change in vibrissae complement in rodents leads to long-term changes in vibrissae dominance. These changes involve both potentiation of spared vibrissae responses and suppression of deprived vibrissae responses in adolescent animals. In adult animals only potentiation of spared vibrissae responses was detected. Suppression exhibits hetero- and homosynaptic components and appears to be cortical in origin, as is potentiation. The time course for potentiation and suppression in the barrel cortex of adolescent rats is different, with suppression preceeding potentiation by at least one week. There seems to be no critical period for potentiation in superficial layers of barrel cortex, but there is a critical period for suppression. Suppression cannot be evoked if plasticity is induced later than at 6 months of age nor maintained if experimental manipulations begin later than at three months. The molecular mechanisms that underlie plastic changes in the barrel cortex still remain unclear, although alpha-CamKII and to lesser extend alpha/beta-CREB appear to be involved.
Urgensi Keberadaan Otoritas Pengawasan Independen Terhadap Harmonisasi Hukum Perlindungan Data Pribadi Di Indonesia
Authors: Halbert Giovanno , Rusdiana Shelvi , Hutauruk Rufinus Hotmaulana
Published: December 2023

Personal data is one of the most crucial aspects in Indonesia, which has been following the digital development. Unlike Singapore and Japan, which already have institutions overseeing the protection of personal data, Indonesia does not have one yet and is still aspiring to establish an independent supervisory authority that can assist the public in personal data protection. This research employs a normative juridical study with a legal approach and a conceptual approach. The result of this research is the need for harmonization between Law Number 27 of 2022 on Personal Data Protection and Law Number 11 of 2008, as amended by Law No. 19 of 2016 on Electronic Information and Transactions, with the regulations of Singapore's Personal Data Protection Act and Japan's Act on the Protection of Personal Information as a comparative model to establish an independent institution regulating personal data in Indonesia.