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The morphometric characteristics and distribution of Clarke’s nuclei in the gray matter of the spinal cord were studied in cats by histochemical detection of acetylcholinesterase, an immunohistochemical marker for non-phosphorylated domains of neurofilament heavy chains (SMI-32) and the Kluver–Barrera method for detection of myelinated fibers. Results averaged for five cats yielded metric maps of segments LI–IV of the spinal cord with superimposed spatial coordinates of the boundaries of Clarke’s nuclei. These studies provide the information required for more precise stereotaxic access to Clarke’s nuclei for investigations in future research and applied studies.

The effects of rhythmic light stimulation on the postnatal development of the visual system were studied in relation to the formation of Meynert neurons in field 17 and the posteromedial area of the lateral suprasylvian sulcus (PMLS) in kittens reared with exposure to flashing light (frequency 15 Hz). Neuron body cross-sectional area and cytochrome oxidase (CO) activity levels were measured in the visual cortex of control (n = 6) and stimulated (n = 6) animals. Increases in the level of CO activity were seen in Meynert cells in field 17 and the PMLS area, by about 37%. There was also a decrease in the cross-sectional area of the bodies of Meynert neurons located in the PMLS, by 20% compared with normal. The existence of functional impairments of the Y conducting channel in stimulated animals and the possibility that binocular vision is suppressed are discussed.

The influences of artificial binocular rhythmic light stimulation on the development of the structural-functional organization of Y neurons in the cat visual system during ontogeny were studied by assessing the distribution of neurons immunopositive for SMI-32 antibodies in the lateral geniculate body (LGB) and posteromedial zone of the lateral suprasylvian sulcus (PMLS). The layer-by-layer distribution of SMI-32-positive neurons was analyzed, along with the cross-sectional areas of their bodies, in intact animals (n = 4) and cats reared in conditions of rhythmic light stimulation at a frequency of 15 Hz for four months (n = 4). Stimulated animals showed changes in the layer-by-layer distribution of immunopositive neurons both in the LGB (decreased proportion of immunopositive cells in layer CM) and the PMLS (decreased proportion of immunopositive cells in layer V). Morphometric analysis showed that in stimulated cats there was a significant decrease in the cross-sectional area of the bodies of immunopositive neurons only in layers III and V in the PMLS. These data suggest functional impairments to the Y-conducting channel in stimulated animals, due to structural-metabolic changes to Y neurons.

The plasticity of visual corticocortical connections during ontogeny in an experimentally altered visual environment (stimulation with flashing lights) was studied by investigating the development of axonal connections between the primary visual cortex (field 17) and the visual movement analysis center in cats. A method based on retrograde axon transport using horseradish peroxidase as marker was used to study the distribution in field 17 of start neurons sending afferent fibers to the posteromedial part of the lateral suprasylvian sulcus in 16 kittens aged 5 and 12–14 weeks in conditions of a normal visual environment or with stimulation with flashing light (15 Hz). Sessions of stimulation with flashing light were found to lead to impairment to the normal development of the ordered organization of connections between these visual areas, with decreases in the area of labeling and the number of start neurons in field 17. These data clarify the structural grounds for the cortical mechanisms underlying impairments to the processing of information relating to the movement of visual objects in stimulated kittens.

The development of the clustered organization of corticocortical connections between visual field 17 and the posteromedial wall of the lateral suprasylvian sulcus (field PMLS) was studied in cats. The retrograde axonal marker horseradish peroxidase was microinjected into the PMLS region. The distribution of labeled initial neurons was analyzed in field 17 in kittens aged five and 12 weeks. A significant increase in the area of cortex containing labeled neurons and a decrease in their distribution density were seen between week 5 and week 12. Analysis of Fourier amplitude and phase spectra demonstrated differences in the distributions of labeled neurons in kittens of different ages and provided evidence of the incomplete formation of the clustered organization of connections in these animals. The temporal morphofunctional characteristics of the development of intercortical connections of the PMLS zone as compared with other visual areas of the cortex are discussed.

and medicine is one of the most important study tools, as investigations of many current questions in a wide range of scientific directions, including physiology, use images as the initial data form. The first stage in the establishment of the Image Processing Center at the Pavlov Institute of Physiology of the Russian Academy of Sciences in 1996 has been discussed previously [2]. The center was developed as part of Project No. 225 (April 13, 2001) under the auspices of the Federal “State Support for the Integration of Higher Education and Basic Science” program (3.2, “Creation of collective industrial-academic centers with state-of-the-art equipment”). The center became the “Collective Biological and Medical Image Processing Center.” The main user was the Institute of Physiology, while others included St. Petersburg State University and St. Petersburg State Medical University. Financial support for the center under the heading “Development and introduction of information systems for biological image processing and analysis” was continued in 2002 in the framework of the “Mechanisms of adaptive behavior: intracellular signal transduction and gene expression” program of the Presidium of the Russian Academy of Sciences. Expansion of the computerized resources of the center provided biological and medical science research institutions and companies with the ability to process images, as well as facilities for training students and involving them in investigations in the framework of the integration of academic and industrial science. Scientific research programs involving students, post-graduate scientists, and post-doctoral scientists were developed using state-of-the-art computerized image processing methods. The main aim of the present article is to inform colleagues working in different areas of physiology and obtaining experimental data as images of the new capabilities of the center, particularly specialized information systems (SIS) which have been developed and to invite them to take part in collaborative studies. New video-based computer systems are continually being created at the center for processing images in different laboratories of the institute, and new specialized SIS have been developed. These support image processing, formation of databases in subject areas, and the export of results into statistical analysis programs. The facilities at the center support the processing of static and dynamic images of any physiological and biological nature. They provide for the analysis of images reflecting the structural-functional organization of neural networks in the brain, the structural-functional organization of autonomic processes, the neurogenic mechanisms of activity of the internal organs, and the genetic mechanisms of organisms. Images reflecting the mechanisms of sensory and cognitive processes are analyzed, as are those related to the psychophysical image recognition patterns, the mechanisms of neuroendocrine regulation, and the formation of pathological CNS states. Our approach in creating SIS for image processing consists of using the physiological principles of the organiNeuroscience and Behavioral Physiology, Vol. 41, No. 7, September, 2011

Studies on 10 cats aged five and 12 weeks included qualitative and quantitative analyses of the distribution in field 17 of initial neurons organizing corticocortical connections with the posteromedial lateral suprasylvian gyrus (PMLS) of the brain using retrograde labeling with horseradish peroxidase. The PMLS area is a higher center for processing information relating to the movement of visual stimuli. Ontogenetic characteristics of the formation of the ordered (clustered) organization of initial neurons in field 17 were identified. An age-related decrease in the density of initial neurons in field 17 was found, from 125.2 ± 69.8 cells/mm2 in kittens aged five weeks to 34.7 ± 17.4 cells/mm2 in 12-week-old kittens (p = 0.05). During the period between postnatal weeks 5 and 12, there was an increase in the size of the labeled area containing the majority of initial neurons. The morphofunctional aspects of the formation of the ordered structure of corticocortical connections between field 17 and the PMLS during postnatal ontogenesis and its possible relationship with the development of the function of the visual perception of moving objects are discussed.

Cytochrome oxidase spots in layer IV of field 17 of the primary visual cortex were studied in kittens aged 33, 49, and 93 days, stimulated with a light flashing at a frequency of 15 Hz. The kittens of one group received stimulation from the moment of eye opening until euthanasia (prolonged stimulation); other groups received stimulation for eight days starting from ages 26, 42, or 85 days (transient stimulation), again until euthanasia. Both types of stimulation were found not to alter the geometrical characteristics of cytochrome oxidase spots, but led to significant increases in the contrast of spots located in the splenial gyrus. Increases in spot contrast in the lateral gyrus occurred only after prolonged stimulation to age 93 days or after transient stimulation from age 26 days to age 33 days. Thus, stimulation of kittens of different ages with a light flashing at a frequency of 15 Hz led to structural-metabolic changes in the primary visual cortex. These changes were apparent to different extents in areas of the cortex responsible for central and peripheral vision. This may be explained, firstly, by the predominant activation of the Y conducting channel of the visual system and, secondly, by the increase in dominance of the contralateral input to the primary visual cortex.

The distribution of the enzyme cytochrome oxidase (CO) in continuous series of parasagittal sections from field 17 and frontal sections of the dorsal nucleus of the lateral geniculate body (LGB) from normal kittens and adult cats was studied. In all cats apart from neonates, layer IV showed regularly alternating areas with above-background levels of CO activity ("spots"). There was a significant increase in the contrast of the "spots" from days 13 to 21, which was followed by a significant decrease from days 48 to 93. These changes coincided with ontogenetic changes in the level of visual system plasticity. There were no differences in CO activity between layers A and A1 of the dorsal nucleus of the LGB. It is suggested that the non-uniform distribution of the level of functional activity of neurons in field 17 reflects the formation of columnar cortical structures during the critical period of postnatal ontogenesis.

The distributions of retrograde labeled cells in fields 17 and 18 and the fields 17/18 transitional zone were studied in both hemispheres of cats after microiontophoretic administration of horseradish peroxidase into individual cortical columns in fields 17, 18, 19, and 21a. The clustered organization of the internal connections of the cortical fields, the asymmetrical locations of labeled callosal cells relative to the injected columns, and the defined distribution of labeled cells in layers A of the lateral geniculate body suggested that eye-specific neuronal connections support "binding" of the visual hemifields separately for each eye. Application of marker to columns in fields 19 or 21a demonstrated disparate inputs from fields 17 and 18 and the fields 17/18 transitional zone. It is suggested that these connections may support the extraction of loci and stereoscopic boundaries located in the central sectors of the visual space.

Experiments on three groups of rhesus macaques (intact and with bilateral removal of field 7 and the sulcus principalis) were performed to study the functional characteristics of the associative areas of the cortex while the monkeys learned visual discrimination. Significant differences in learning processes associated with removal of structures and the properties of the stimuli were seen in all animals, in the form of different types of learning curves. As compared with intact monkeys, removal of field 7 had no effect on learning processes for images with properties such as spatial frequency, color, and animal images, though there was a significant worsening in the characteristics of learning during visual discrimination of spatial relationships between objects. Learning processes became unstable, the number of peaks and troughs on learning curves increased, and as a result the training periods were significantly lengthened and 85% of the animals were unable to achieve the learning criterion. Removal of the sulcus principalis significantly worsened the characteristics of discrimination of the sizes of geometric objects, the spatial relationships between them, and stimuli of different colors. The stable reaction time and the probability of refusal in most cases also increased for monkeys of both these groups. Cluster analysis based on the quantitative characteristics of learning processes, despite individual differences between the monkeys, demonstrated a tendency for stimuli to be separated into classes corresponding to different types of information. These data show that the result of sensory processing is that several (at least three) functional visual information flows are generated and that different areas of the cortex deal with these different flows.

Microiontophoretic application of horseradish peroxidase to individual columns in fields 17 and 18 of the cat cortex was used to identify the distribution by area and layer of retrograde labeled cells in both fields. After application of marker to fields 17 or 18, the area of labeled cells in field 17 (in the tangential plane) was extended and orientated along the projection of the horizontal meridian of the field of vision. The area of labeled cells in field 18 in these cases was orientated along the projections of the vertical meridian. Similar differences in the organization of the connections of fields 17 and 18 were seen in the projection zone of the central 10° of the field of vision at different elevations. Thus, the spatial distributions of internal and external connections in each field coincide and their orientations in fields 17 and 18 are mutually perpendicular. It is suggested that field 17 performs the more detailed analysis of information on the horizontal components of an image and communicates this to field 18, while field 18 is responsible for the more detailed analysis of information about the vertical components of the same image, communicating this to field 17.

To examine the effect of rhythmical light stimulation on postnatal development of the visual system, the formation of Meynert cells was studied in area 17 and posteromedial suprasylvian area (PMLS) of kittens reared under the conditions of flickering light stimulation (15 Hz frequency). Profile area of neuronal cell bodies and cytochrome oxidase (CO) activity level were measured in frontal sections of the visual cortex in control (n = 6) and stimulated (n = 6) kittens. Meynert cells located in area 17 and PMLS demonstrated an approximately 37% increase in CO activity in the stimulated animals. At the same time, the profile area of Meynert cell bodies in PMLS was decreased by 20% as compared to that in normal animals. The presence of functional disturbances of Y-conducting visual channel and the possibility of binocular vision suppression in the stimulated animals are discussed.

To examine the effect of an artificial rhythmic light stimulation on the development of structural and functional organization of Y neurons of cat visual system in the ontogenesis, the distribution of the neurons immunopositive to SMI-32 antibodies was studied in lateral geniculate nucleus (LGN) and posteromedial suprasylvian area (PMLS). Laminar distribution of SMI-32-positive neurons and neuronal body profile area were analyzed in intact animals (n = 4) and in kittens (n = 4) grown under conditions of rhythmic light stimulation with 15 Hz frequency for 4 months. In light-stimulated animals, changes in laminar distribution of immunopositive neurons were detected in both LGN (decline in the percentage of the immunopositive cells in C(M) layer) and in PMLS area (decrease in cell count in layer V). Morphometric analysis has shown the significant reduction of cell body profile area in immunopositive neurons in light-stimulated kittens only in layers III and V of PMLS area. The data obtained suggest that Y channel functional disturbances in light-stimulated animals are caused by the structural and metabolic changes detected in Y neurons.

Sprague-Dawley rats (weight 130-150 g) were sensitized by an intraperitoneal injection of 1 mg chicken egg albumin with 0.25 ml Freund's adjuvant to stimulate immunoglobulin E antibody production. Leukocyte migration inhibitory factor was used as an indicator of animal sensitization. In acute electrophysiological experiments on sensitized animals, an intra-arterial or intraluminal chicken egg albumin (100 microg) challenge evoked a 10% enhancement of the activity of mesenteric nerves of the small intestine, regardless of the injection site chosen. Afferent nerve activity in control animals was not changed during the chicken egg albumin challenge. Morphometry at the light microscope level showed activation of mast cell degranulation after the antigen challenge to presensitized rats. Intraluminal injections of a stimulator of mast cell degranulation, compound 48/80 (20-30 mg), were found to increase afferent discharges in intact rats. An antagonist of H1 histamine receptors, clemastine, reduced the effect of compound 48/80. The results obtained provide direct evidence for the stimulation of sensory nerve endings by mast cell mediators released during mast cell degranulation.

Monkeys (Macaca mulatta) with preliminary removal of field 7 of the lower parietal cortex and previously trained to differentiate images differing in shape, color, size, orientation, and spatial relationships were used to study the processes involved in short-term storage of different types of information required for a delayed (by 0-8 sec) visual differentiation task and the effects on these processes of the antioxidant Oxymetacil. Significant differences were found in comparison with intact animals. Removal of field 7 sharply worsened short-term storage processes during visual differentiation of different types of images, including those differing in terms of properties such as color, geometrical shape, and the spatial relationships between image elements. There were significant reductions in the level of correct responses for all delay periods with significant increases in the motor reaction time, indicating a sharp reduction in the duration of short-term information storage, which suggests that the monkeys' short-term memory mechanisms were disrupted. Oxymetacil had a correcting effect only in relation to stimuli differing in terms of color and shape, but had no effect at all on the short-term storage of spatial information. It is suggested that these data suggest that field 7 has at least two functions. These are, firstly, a role in processes underlying the evaluation, differentiation, and storage of spatial information depending on visual-vestibular interactions, and secondly, a role in the mechanisms underlying the attention system, which is disrupted by removal of field 7 and restored by treatment with the antioxidant when there is no need to differentiate spatial information, a process which depends on assessment of the body image and egocentric orientation based on visual-vestibular interactions.

Studies were carried out on the organization of the internal connections of the striate cortex in cats in the projection zone of the center (0-5 degrees) of the field of vision by microintophoretic application of horseradish peroxidase to electrophysiologically identified orientational columns. The area containing neurons showing retrograde labeling in most cases extended in the mediolateral direction. Labeled cells were located in the upper (II, III) and lower (V, VI) layers of the cortex, and the shapes and orientations of the areas containing labeled neurons in these layers coincided. Spatial asymmetry was detected in the distribution of labeled neurons relative to the orientational column studied. Labeled cells were located predominantly medial to the columns, regardless of the distance from the projection of the area centralis. Considering the visuotopical map of field 17, the asymmetry detected here provides evidence that neurons in orientational columns have more extensive connections with neurons of the peripheral part of the cortex. An asymmetrical distribution of "silent" 2 zones around the receptive fields of neurons in orientational columns is suggested, and that these appear to receive influences from the periphery of the visual field.

Development of axonal connections between cat primary visual area 17 and visual motion processing center was studied to investigate cortico-cortical connection plasticity in ontogenesis as affected by an experimental modification of visual environment (flickering light stimulation). By using a retrograde axonal labeling by horseradish peroxidase, a distribution of initial neurons in area 17 that send afferent projections to PMLS (posterior medial part of lateral suprasylvian sulcus) was analyzed. Sixteen 5-week-old and 12-14-week-old kittens, than were reared in normal visual environment or were subjected to a flickering light of 15 Hz frequency, were examined. It was shown that session stimulation by flickering light led to an impairment of normal development of regular organization of the connections between these visual areas including the decrease of labeled surface area and labeled initial neuron density in area 17. The data obtained elucidate the structural bases of cortical mechanisms that underlie motion processing disturbances in kittens stimulated by a flickering light.

Using cortico-cortical connection analysis technique, the cat visual area PMLS (the area located on posterior medial wall of the lateral suprasylvian sulcus) retinotopic organization was investigated. A retrograde axonal tracer: horseradish peroxidase (HRP), was injected in the PMLS, and initial neurons were investigated in area 17. It was shown that after HRP injection in PMLS locus, where a central vision field is located, a labelled cell pattern in area 17 corresponded to the L. Palmer et al., 1978, retinotopic map. On the contrary, after HRP injection in PMLS locus, where an upper vision field must be located, as L. Palmer et al., 1978 predicted, initial neurons are visualized in area 17 loci where low visual periphery is displayed: -10 degrees to -60 degrees in vertical meridian and 40 degrees to 80 degrees in horizontal meridian. Such discrepancy in upper and lower visual field representation was also obtained in electrophysiological and topographic investigations by Grant, Shipp, 1991. The data suggest necessity of S. Grant and S. Shipp's retinotopic map use in the cat area PMLS morphofunctional investigation.

Early ontogenetic development of cluster organization of corticocortical connections between visual areas 17 and posteromedial lateral suprasylvian area (PMLS) was studied in cat. Retrograde axonal tracer horseradish peroxidase was microinjected into the area PMLS. Labeled initial neuron distribution was analyzed in area 17 in 5- and 12-week-old kittens. A significant increase of the cortical surface area containing labeled neurons together with the decrease in their distribution density were shown between weeks 5 and 12. An analysis of amplitude and phase of Fourier spectra of labeled neuron distribution patterns demonstrated some differences between the kittens of various age groups and indicated the incompleteness of connection cluster organization formation. The temporal morpho-functional features of the development of PMLS zone corticocortical connections, as compared to the other visual cortical areas, are discussed.

Neuronal sites in the dorsal motor nucleus of the vagus nerves sending out axons to the duodeno-jejunal junction and the upper jejunum were located during acute experiments on cats using retrograde horseradish peroxidase transport techniques. A large proportion of these cells are found in the ventrolateral region of the nucleus at distances of 1.0–2.7 mm from the obex. Morphological aspects of nodose ganglion neurons responsible for afferent intestinal innervation were also investigated, showing the largest numbers of such cells to be located in the medial and caudal portions of the ganglion.

Spatial organisation and quantitative features of cortico-cortical neurons in area 17 that project to area 21a of cat visual cortex were investigated. We used the HRP technique and two-dimensional reconstruction from serial sections of brain. Pattern of distribution of labelled cells in some regions of areas 17 and 18, on the lateral and medial surface of the brain were analysed. The data about cluster organisation of cortico-cortical neurones, localisation, layer distribution and density of neurons were obtained.

A quantitative and qualitative analysis of distribution of initial cells that organize the cortico-cortical connections between area 17 and posterior-medial lateral suprasylvian area (PMLS) was carried out in 10 kittens (5- and 12-week old). A horseradish peroxidase labeling technique was used. PMLS area is the highest center of moving visual stimuli information processing. Certain ontogenetic peculiarities of the area 17 initial neurons regular (clustered) organization were revealed. An age-related decreasing of the area 17 initial neurons packing density was shown (from 125.19 +/- 69.75 cells/mm2, in 5-week kittens to 34.67 +/- 17.38 cells/mm2--in 12-week kittens (p = 0.05)). It was shown also that an increasing of striate cortex locus that contained a gross majority of marked neurons occurs from 5-th to 12-th postnatal week. Possible morpho-functional aspects of ontogenetic formation of connections between area 17 and area PMLS clustered structure and its possible relation to development of visual moving stimuli perception are discussed.

This review summarises both classical and current literature data on the structure and the histogenesis of the retina of the mammalian eye and, in particular, of its specialized region--area centralis. The review describes the modem concepts of cytoarchitecture of area centralis, as well as the peculiarities of its blood supply, and presents the details of its histogenesis from early embryonic stages to postnatal development.

The localization and morphometric features of the preganglionic neurons of the spinal sacral parasympathetic nucleus innervating the descending colon and the rectum, were studied in cats, anesthetized with urethane (1.5 g/kg intraperitoneally) using the method of retrograde horseradish peroxidase transport. The solution of the marker was injected under the serosa of the indicated areas of the colon. After 48 h the animals were transcardially perfused with a fixative solution. Frontal sections of the sacral spinal segments were prepared and stained according to M. Mezulam's protocol (1978). It was demonstrated that the indicated areas of the colon were innervated by the neurons of the sacral parasympathetic nucleus, located in SI, SII and SIII segments of the spinal cord. The majority of the labeled cells were observed within SII segment. The neurons of this nucleus, which innervated the indicated areas of the colon, formed two longitudinal groups (lateral and dorsal ones), the cells in which differed by their sizes and longitudinal axis orientation. Most of the labeled cells were detected in the lateral group.

CO "spots" in layer IV of primary visual cortex were investigated in 33, 49 and 93-days kittens that were subjected to flickering light stimulation. Kittens from first group were stimulated since eye opening (long-term stimulation), other kittens--since postnatal day 26, 42 or 85 until euthanasia (short-term stimulation). Both types of stimulation did not disturb CO "spots" spatial organization but obviously increased a contrast of splenial CO "spots". Lateral "spots" contrast increasing took place after long-term stimulation until the 93rd postnatal day or after short stimulation since 26th to 33rd postnatal day. Flickering light stimulation seems to lead to structural and metabolic alterations in primary visual cortex. These alterations are processed in different way in regions of area 17 that is responsible for central and peripheral vision, respectively. It seems to reflect, firstly, primary activation of Y processing stream and, secondly, the strengthening of contralateral input to area 17.

The localization and morphometric features of efferent parasympathetic neurons of the vagus dorsal motor nucleus and of the spinal sacral parasympathetic nucleus innervating the area of ileocaecal sphincter, ascending and transverse colon, were investigated. In urethane anaesthetized cats, the solution of horseradish peroxidase was injected under the serosa of the indicated areas of colon. In 48 hours animals were transcardially perfused with a fixative solution. Sections of the medulla oblongata and the sacral spinal cord were stained using Mezulam's technique (1978). It was shown that all the areas of the colon studied received parasympathetic innervation from the neurons of the ventrolateral part of the vagus dorsal motor nucleus, which were uniform according to their morphometric characteristics. The number of neurons in this group, sending their axons to the ileocaecal area, was greater than the number of neurons, innervating ascending colon. Second group of neurons, that was represented by smaller cells, was located in the same part of the nucleus and innervated transverse colon. Transverse colon had an additional parasympathetic supply from the neurons of the spinal sacral parasympathetic nucleus.

Distribution of enzyme cytochrome oxidase (CO) activity was studied in a continuous series of parasagittal sections of cortical area 17 and frontal sections of dorsal lateral geniculate nucleus (LGNd) in kittens of different age and adult cats. In all the kittens except the newborns, in layer IV of area 17, regular alternating areas of CO activity, exceeding the background activity ("spots"), were detected. During the period between postnatal days 13 and 21 a significant increase of "spots" contrast took place, while between postnatal days 48 and 93 contrast was significantly decreased. This contrast changes coincided with the dynamics of visual system plasticity during ontogenesis. No differences in CO activity were detected between layers A and A1 in LGNd. It is suggested that non-uniform distribution of functional activity of area 17 neurons reflects the development of cortical columns during the critical period of postnatal ontogenesis.

Studies in anesthetized (urethane, 1.5 g/kg, i.p.) cats using retrograde transport of horseradish peroxidase addressed the locations and morphometric characteristics of neurons in the sacral parasympathetic nucleus of the spinal cord innervating the descending colon and rectum. Marker solution was injected beneath the serous membrane of the study areas of the large intestine. Transcardiac perfusion with fixative solution was performed 48 h later and frontal sections of the sacral segments of the spinal cord were prepared; these were processed by the Mesulam method (1978). The results showed that these areas of the large intestine receive innervation from neurons in the sacral parasympathetic nucleus located in spinal cord segments SI, SII, and SIII. The largest number of labeled cells was seen in segment SII. The neurons of this nucleus innervating the study areas of the large intestine formed two longitudinally distributed group (a lateral and a dorsal), the cells of which differed in terms of size and the orientation of the long axis. The largest number of labeled cells was seen in the lateral group.

The locations and morphometric characteristics of efferent parasympathetic neurons in the dorsal motor nucleus of the vagus nerve and the cruciform parasympathetic nucleus of the spinal cord, innervating the area of the ileocecal sphincter and the ascending and transverse segments of the colon, were studied. Horseradish peroxidase solution was injected beneath the serous membranes of these parts of the intestine in urethane-anesthetized cats. After 48 h, animals were subjected to transcardiac perfusion with a fixative mixture and sections of the medulla oblongata and spinal cord were prepared and processed by the Mesulam method. The results showed that all these parts of the large intestine received parasympathetic innervation from neurons in the ventrolateral part of the dorsal motor nucleus, which were uniform in terms of their morphometric characteristics. The number of neurons of this group sending axons to the ileocecal area was greater than the number of neurons innervating the ascending colon. A second group of neurons, which were smaller cells, was located in the same part of the nucleus and innervated the transverse colon. The transverse colon also received innervation from neurons in the cruciform parasympathetic nucleus of the spinal cord.

The localization and morphological features of viscerosensory neurons of sacral spinal ganglia (SSG), innervating the colon, were investigated. In urethane anaesthetized cats, the solution of horseradish peroxidase was injected under the serosa of ascending and descending parts of the colon as well as of the rectum. After 48 hours animals were repeatedly anesthetized and transcardially perfused. Sections of SSG were stained according to Mezulam protocol (1978). All the regions of the colon studied were shown to receive afferent innervation from neurons of SSG SI, SII and SIII. Maximum number of the labeled cells was detected in SSG SII. The intensity of afferent innervation of the colon by the neurons of SSG was found to increase along its length in cranio-caudal direction.

The spatial distribution of neuronal connections in cortical area 17 in cats with bilateral convergent strabismus, surgically induced on postnatal days 10-14, was investigated. Single cortical columns of areas 17 and 18 were microiontophoretically injected with horseradish peroxidase and retrogradely labeled cells in both hemispheres were detected. The intrahemispheric connections in area 17 along the mediolateral direction (the projection of visual field horizontal meridian) were found to be either dilated or reduced. For most columns, the interhemispheric connections in this direction were increased, which may provide for more reliable unification of two visual hemifields. Moreover, the extension of intra- and interhemispheric connections in rostrocaudal direction (along the visual field vertical meridian projection) was detected in some cortical columns. Thus bilateral strabismus induced during the developmental critical period, modifies the structure of both of intra- and inter-hemispheric spatial neuronal connections of individual cortical columns in areas 17 and 18.

Processes of novelty learning and keeping the results in Alzheimer's disease in two groups of rhesus-monkeys (three monkeys in each group), were studied: following neurotoxins administrati- on (I group) and saline administration (II group). In two months after the injections (the C1 stage), considerable differences between the groups were revealed in the task of differentiation among contour shapes. For the I group monkeys the learning was difficult: the correct decision making did not reach 85 %, and the probability of refusing to make a decision increased. For the II group monkeys the learning characteristics were not disturbed. In six months after the injections (the C3 stage) the differences between the groups in the task of differentiation among new stimuli (heads of two monkeys) remained at the same level. When studying characteristics of the operative memory associated with keeping the learning results achieved at the C1 stage, a considerable worsening of these characteristics was revealed: diminishing of the correct decision making probability at the C1 stage (actually to the level of 0.5), increase in the probability of refusing to make a decision. The structural-functional organization of interaction between sensory and cognitive processes in learning and keeping the information in the operative memory, is discussed in association with the control of motivation and attention system and the role of the cortex associative areas.

The first part of the present study used a model of Alzheimer's disease in two groups of animals (three monkeys in each), given injections of neurotoxins (monkeys of group I) and physiological saline (monkeys of group II). Before injections, all monkeys were trained to discriminate stimuli containing different types of information (spatial frequency grids and geometrical figures of different colors and with different spatial relationships between objects) and to perform spatial selection. The dynamics of impairments in the characteristics of working memory were identified using delayed differentiation tasks in monkeys of both groups before injections and every two months after injections. Quantitative measures of impairments were made using the entropy of visual recognition, which characterizes uncertainty in decision-taking. The development of Alzheimer's disease in rhesus macaques was characterized by a deficit of working memory, resulting from lesions to the two component processes of memory. Impairments of the first of these in monkeys of group I were manifest as a significant increase in entropy, which is associated with correct decision-taking. The magnitude of the increase depended on the type of visual information. Impairments of the second component were characterized by increases in entropy associated with refusals to take decisions and were independent of the delay duration and the type of visual information. Monkeys given injections of physiological saline showed no significant changes in these characteristics. The features of working memory were also studied in the second part of the investigation, using four groups of Rhesus macaques: intact, those with bilateral extirpation of the sulcus principalis or field 7 or both: degradation again identified two components. Entropy associated with this was increased significantly for most of the stimuli tested on monkeys of all extirpation groups as compared with intact animals. Significant differences were found in these characteristics for a number of stimuli, which depended on the location of the structures removed. The characteristics of impairments of the components of working memory resulting in the development of Alzheimer's disease showed that the cholinergic mechanisms responsible for sensory processing differ from those involved in decision-taking. The structural-functional organization of the interaction of sensory and cognitive processes controlled by the motivation and attention systems is discussed, as is the role of the associative areas of the cortex.

The objective of this study was to analyze the influence of the light flickering with the frequency of 15 Hz, on the neuronal metabolic activity in kittens reared under the conditions of mesopic illumination. The method for demonstration of a respiratory enzyme cytochrome oxidase was used to study the visual cortex areas 17 and 18 and the lateral geniculate nucleus. It was shown that in kittens that were subjected to this stimulation as opposed to intact animals and to kittens reared under the conditions of mesopic illumination, specific changes in pattern of cytochrome oxidase distribution in area 17 took place. This change was manifested by the appearance of alternating zones of increased and decreased enzyme activity in layers III and IV. Within the cortical area 18 and lateral geniculate nucleus, no changes in the pattern of cytochrome oxidase activity distribution were detected in experimental kittens. It is suggested that flickering illumination results in disequilibrium of Y- and X-visual pathway activity.

The spatial distribution of neuronal connections in cortical field 17 was studied in cats with experimentally induced bilateral convergent strabismus on postnatal days 10-14. Horseradish peroxidase was applied microiontophoretically to individual columns of neurons in fields 17 and 18 and retrograde-labeled cells were identified in both hemispheres. Increases and decreases in the extent of intra-hemisphere connections were seen in the mediolateral direction (projections of the horizontal meridian of the visual field). Most columns showed increases in inter-hemisphere connections in this same direction, which may support the more reliable unification of the two visual hemifields. In addition, some columns showed increases in intra-and inter-hemisphere connections in the rostrocaudal direction (projections of the vertical meridian). Thus, bilateral strabismus induced during the critical period of development leads to changes in the structure of both intra-hemisphere and inter-hemisphere connections of individual cortical columns in fields 17 and 18.

The spatial distribution of horizontal internal connections in field 17 of the cat cortex was studied after microiontophoretic application of horseradish peroxidase to individual cortical columns. Cluster analysis of the distribution of labeled cells in the superficial layers in the tangential plane of the cortex was performed. Field 17 included 7 +/- 1 clusters of up to five cells. Clusters were distributed into two layers, separated by 1.2 +/- 0.3 mm. The distance between the centers of the clusters forming rows was 0.8 +/- 0.3 mm. The spatial characteristics of the grouping of cells sending axons into the cortical column were compared with published data based on optical visualization of the activity of neurons in orientational and eye-dominant columns of the visual cortex. It is suggested that columns in field 17 are associated with 6-8 hypercolumns, though only with a single type of neuron within these hypercolumns, in terms of eye dominance and orientational preference.

The interhemispheric connections of areas 17 and 18 of the cerebral cortex were investigated in cats with experimental unilateral strabismus. Single cortical columns were microiontophoretically injected with horseradish peroxidase, and retrogradelly labeled cells were demonstrated in the opposite brain hemisphere. After tracer injection in area 18 columns, the labeled callosal cells were located in area 17/18 transitional zone, similar to what was found in normal cats. However, in some cases the expansion of the region of callosally labeled cells distribution, was found. It is proposed that the extent of the region of callosally-connected cells may vary depending on whether the cells receive their input from intact or strabismic eye.

Horseradish peroxidase (HRP) was applied microiontophoretically to nine individual columns in fields 17 and six columns in field 18 of the cat cerebral cortex. Most labeled cells in the dorsal lateral geniculate body were identified in layer A. The ratio of number of labeled cells in layer A to the number of labeled cells in layer A1 was assessed (the A/A1 ratio). Application of HRP to columns in field 17 yielded A/A1 ratios of 0.5 to 2.5; application to field 18 gave ratios ranging from 0.2 to 0.9. This suggests that the fields studied here contained columns which were afferent in relation to the ipsilateral eye and the contralateral eye.

The processes of learning and storage of the results of learning were studied in a model of Alzheimer’s disease in two groups of rhesus macaques (three individuals in each group). Studies were performed after injection of neurotoxins (group I) and physiological saline (group II, controls). Two months after injections (stage C1), learning parameters were studied in monkeys of both groups using a new stimulus discrimination test (filled geometrical figures versus outline figures). There were significant differences between the animals of the two groups. Learning was hindered in monkeys of group I, with significant increases in the learning time (the time to achieve a stable probability of correct responding of 0.85) and in the probability of refusals. Monkeys of group II showed no learning impairment. Animals were trained to discriminate new stimuli (images of two monkeys) six months after injections (stage C3). Learning was impaired in animals of group I, such that learning measures had the same levels as previously; monkeys of group II showed no learning impairment. Analysis of the characteristics of working memory, which is involved in storing the results of new learning, was performed at stage C1; monkeys of group I showed significant degradation of these measures, with a significant decrease in the probability of correct solutions at stage C1 (to a level of 0.5), with some increase at stages C2 (at four months) and C3, along with a significant increase in the probability of refusals, values being similar at all time points. For monkeys of group II, these characteristics showed no degradation. Motor response times at stages C1, C2, and C3 were not different for the two groups of monkeys. The structural-functional organization of interactions between sensory and cognitive processes during learning and the storage of information in working memory are discussed, as is the role of the associative areas of the cortex in these interactions.

Two groups of monkeys were learned to differentiate stimuli with different types of information and to make a spatial choice. Characteristics of the operative memory were revealed in the delayed differentiation tasks prior to and after administration of p75-saporin (I group) and saline (II group). For the first time the Alzheimer disease in monkeys was shown to entail a deficit of operative memory due to disorders in the sensory and cognitive components of the memory. The degree of reduction of the correct decision making was shown to depend on the delay duration and the type of visual information. Following the saline administration, no significant changes occurred in the monkeys (II group). The data obtained suggest that structural-functional organisation of the cholinergic and noradrenergic mechanisms predetermining the sensory processing, differs from those involved in decision-making.

Monkeys were taught to differentiate stimuli with different types of information and to perform a spatial choice. Development of Alzheimer's disease in experimental monkeys entailed a deficit of operative memory, a considerable enhancement of entropy related to correct decisions. In control monkeys, no significant changes of these characteristics occurred. In monkeys, following a bilateral removal of the sulcus principalis, the 7th field, or both, the operative memory deficit was also determined by two components. The specifics of disorders in the operative memory due to Alzheimer's disease suggest that cholinergic mechanisms determining the sensory processing differ from those involved in decision-making. The structural-functional organization of interaction between sensory and cognitive processes controlled by the motivation and attention system, is discussed.