Biomedical subjects

P Petrovický

Publications and source records attributed to P Petrovický.

At least 19 recordsLinked to original sources

PubMed2006

Amygdalar volume and psychiatric symptoms in Alzheimer's disease: an MRI analysis.

OBJECTIVES: We measured the volumes of the amygdala to test the hypothesis that the reduction of amygdalar volume may be associated with psychiatric symptoms in Alzheimer's disease. MATERIALS AND METHODS: Twenty-seven patients underwent neuropsychological investigation including the assessment of general clinical severity by the Mini-Mental State Examination (MMSE) and Neuropsychiatric Inventory (NPI). All patients underwent magnetic resonance imaging (MRI) of the head, from which the volumes of the amygdalae were measured. The obtained values were compared with those of controls (n = 15). RESULTS: Patients with Alzheimer's dementia showed significant reduction in MRI volumetric measurements compared with controls. We found a significant correlation of MMSE score and absolute amygdala volume (r = 0.62, P < 0.01). Neither the absolute nor relative volume of the amygdala showed any correlation with NPI scores. CONCLUSIONS: The atrophy of the amygdala does not have a direct association with the existence of neuropsychiatric symptoms. MRI volumetry of the amygdala may be relevant as a marker of dementia severity in Alzheimer's disease.

Aged↗

PubMed2003

Neuroendocrine immune interactions in health and disease.

The purpose of this paper is to review ways in which the neurohormonal system can interact with the immune system and to outline the main mechanisms which are involved in this interaction. Experimental as well as clinical evidence is presented to support the existence of a close interaction and bi-directional communication between the central nervous and immune systems. The role of major endocrine mechanisms and hormones is discussed. The evidences from experimental work to support the roles of the nervous system with neurotransmitters, the endocrine system with hormones, and the immune system with cytokines are presented. Aging, depression and cancer have a high degree of co-association and share mechanisms which result in cellular immune deficiency. Hormone therapy, zinc replenishment, antidepressants, immunomodulators like MDP act on these pathways to upregulate and improve cellular immunity. The authors believe that the central nervous system (CNS)-immune interaction is an important new frontier to be considered for new combination therapy in diseases with cellular immune deficiency such as cancer particularly in the aged with depression.

Animals↗

PubMed2003

Volumetry of striatum and pallidum in man--anatomy, cytoarchitecture, connections, MRI and aging.

BACKGROUND: For comparing of the pathological and normal healthy state it is essential to obtain sufficient amount of the volumetric data. Nevertheless most of the publicized works use only few healthy controls opposite to the patients for the measuring of the basal ganglia volume. Further essential condition is to take into account the effect of age to the basal ganglia volume in such analysis. PURPOSE: The goal of our study was (1) to give the current review of the structure, neurotransmitters, connections and general integration of the basal ganglia in the pathways of the central nervous system, (2) aggregate sufficient amount of volumetric data by virtue of MRI and post-mortem studies, and appoint volumes of the striatum and pallidum, (3) evaluate aging of these structures in adult healthy patients. Another goal was (4) to inspect the correlations between the size of the basal ganglia and volume characteristics of the brain, cranial capacity or frequently measured dimensions within CNS. In the spite of the fact that it is not possible to measure all of these dimensions for clinicians who want to determine if the structure is "normal" or not. Another goal was (5) to find a simple measure, which could serve as the indicator of the real size of structure of the interest. METHODS: By virtue of the classical anatomical methods and MRI examination we appointed volumes of the striatum (furthermore divided into the complex of the caudatum--nucleus accumbens--CD-Acc and putamen) and pallidum in the sample of 108 healthy adults (18-89 years old). From another measurements we calculated the cranial capacity and volume characteristics of each brain. RESULTS: In a general view that does not respect changes due to age neither volumetric difference between two sexes nor interhemispheric difference was significant for absolute volumes of the striatum, CD-Acc complex, putamen and pallidum. In the case of the striatum, significant correlation between size and age was found (p < 0.0001) for absolute volumes in both sexes. In men, striatum showed a decrease about 14.3% in volume in the 20-50-year age range (about 4.8% per decade). In woman, the age related shrinkage is about 16.9% (about 5.6% per decade). Dependence on age was not statistically proven for volume of female complex CD-Acc (p = 0.061). Age related decrease of female putamen was about 23.15% in the 20-50 year age range (7.7% per decade). In men, the seizure decrease of the caudate--accumbens complex amounts 16.2%, in the same age range (5.4% per decade). Similarly, volume of the putamen in men decreases up to 12.3% between 20-50 years of age (4.1% per decade). In men, the pallidum showed a decrease about 21.6% in volume in the 20-50-year age range (7.2% per decade). In women, it amounts only 11.5% (3.8% per decade). Plane of the striatum in the level of the commissura anterior showed high correlation with total striatal volume (p < 0.0001, r = 0.668). The percentual portion of striatal volume at the level of the commissura anterior (1 cm thick slice) does not differ statistically between males and females. In our data it gives 28.56% (SD = 3.05). Correlation between the striatal planes and age was significant in both sexes (in women: p = 0.007, r = 0.348, and in men: p = 0.029, r = 0.349) as in the case of the correlation between striatal volume and age. CONCLUSIONS: Our findings suggest that age mirror differently on separate structures in the brain. We have found unequal volume decrease within both sexes even particular nuclei. Our findings also suggest that decrease of the basal ganglia volume in the dependence on age is not linear but it is composed from periods without changes and periods with reduction of its size. In the case of the striatum, behaviour of changes looks similar (with only 5 years), while in the case of the pallidum this situation is markedly different. Our observations may suggest intersexual singularity in the aging of brain structures. From one MRI, from one frontal slice in the level of the commissura anterior is possible to reduce total volume of the striatum for every examined individual. Simple graph shows interval, where the normal value of this plain should be in dependency on age and sex of the examined patient. Another graph allows reducing from this plane the total volume of the striatum. These findings can be the quick and reliable aid in better diagnostics of different diseases.

Adult↗

PubMed2002

Structures and pathways of the central nervous system are potentially involved in the serotonergic modulation of gastrointestinal activity.

The supposed involvement of rat brain regions in the modulation of rat small intestine serotonergic activity was investigated. Small electrolytic lesions were placed in the areas of medulla oblongata and pons Varoli; one week later, changes in the serotonergic response of the intestine were detected. The contractions mediated by the activation of 5-HT2 receptors in the proximal ileum were investigated. The whole ileum segments were cut and placed into the bath. The preparations were contracted by adding increasing concentrations of 5-hydroxytryptamine (5-HT) (10 nM-1 microM) and noncumulative concentration-response curves (CRCs) were established. The differences between 5-HT responses of preparations from either sham-operated or experimental rats suggest the existence of brainstem regions (dorsal vagal and solitary nuclei, parvocellular reticular nuclei and serotonergic A1,2,5 groups) that either stimulate or inhibit 5-HT modulatory action in the rat gastrointestinal tract.

Animals↗

PubMed2001

Biological properties of copolymer of 2-hydroxyethyl methacrylate with sulfopropyl methacrylate.

Interaction of organism with non-toxic implanted polymers depends on the physicochemical properties of the implant surface, which influence the adsorption of bioactive proteins and subsequently adhesion and growth of cells. The synthetic hydrogels are known as poorly adhesive surfaces. In this study we demonstrated the adsorption of albumin, fibrinogen, fibronectin, basic fibroblast growth factor, heparin-binding epidermal growth factor-like growth factor and epidermal growth factor to poly(2-hydroxyethyl methacrylate) (pHEMA) and copolymer of 2-hydroxyethyl methacrylate (HEMA) and potassium salt of 3-sulfopropyl methacrylate (SPMAK). The adhesion and growth of 3T3 cells and human keratinocytes on surface of these polymers was tested without and with pretreatment of polymers with heparin-binding epidermal growth factor-like growth factor. The adhesion of mixture of human granulocytes and monocytes to these surfaces was also tested. The strips of both polymers were subcutaneously and intracerebrally implanted into the rat and the extent of foreign body reaction and brain biocompatibility was evaluated. The results showed the extensive adsorption of basic fibroblast growth factor and heparin-binding epidermal growth factor-like growth factor to copolymer containing SPMAK. However the adhesion (and growth) of cells to this type of copolymers was very low. Preadsorption of human plasma to pHEMA clearly stimulated the leukocyte adhesion in contrary to copolymer containing SPMAK. The extent of foreign-body reaction was significantly higher against the pHEMA compared to tested copolymer p(HEMA-co-SPMAK). In conclusion, the tested copolymer was a poorly adhesive substrate that is only poorly recognized by the non-specific immunity, although the adsorption of basic growth factors to this substrate is highly significant. Both polymers were well tolerated by the brain tissue. The phenotype of surrounding neurons was more close to the control neurons in the brain tissue surrounding the p(HEMA-co-SPMAK) implants.

Journal Article↗

PubMed2000

Past, present and future of psychoneuroimmunology.

Psychoneuroimmunology was for the first time comprehensively described about 20 years ago. The influence of mental status on the course and outcome of a number of diseases, however, was suspected a long time before. Also the links between mental affective disorders and the immune status were repeatedly suggested. The authors in this paper shortly reviewed the most important clinical as well as experimental evidence which at present strongly supports the concept of a close and bidirectional communication between central nervous, neuroendocrine and immune systems. The most important anatomical, physiological as well as pharmacological experimental data, which were obtained by the authors during 20 years of research in this field, are presented. The data strongly suggest that in the very next future we will not only better understand a very complex communication between mind and body, but also completely new types of compounds might become available.

Animals↗

PubMed2000

The effect of electrolytic thalamic lesions on the NADPH-diaphorase activity of neurons of the laterodorsal tegmental and pedunculopontine nuclei in rats.

Cholinergic neurons of the mesopontine complex have extensive ascending projections to the forebrain: the laterodorsal tegmental nucleus extensively innervates the anterior thalamus, the anteroventral nucleus in particular, whereas the pedunculopontine nucleus has widespread projections to both the thalamus and extrapyramidal structures. Most of their neurons express nitric oxide synthase (NOS) activity. Following electrolytic lesions of the anteroventral thalamic nucleus, nicotinamide adenine dinucleotide phosphate-diaphorase (NADPHd) activity in neurons of the laterodorsal tegmental nucleus changed drastically. The intensity of NADPH-diaphorase staining increased in laterodorsal tegmental neurons ipsilateral to the lesion side, but decreased contralaterally. The intensity of the NADPH-diaphorase staining of neurons of the pedunculopontine nucleus, however, remained unchanged bilaterally. After partial lesions of the anteroventral thalamic nucleus a similar effect was noted. In contrast, large electrolytic lesions involving other thalamic nuclei or extrapyramidal structures did not change the number of NADPH-diaphorase neurons or their intensity of staining in the laterodorsal tegmental nuclei. These data show that electrolytic lesions of target areas can lead to an upregulation of NOS expression in the parent cell bodies, provided that there is no wide collateralization as found for the pedunculopontine nucleus.

Animals↗

PubMed2000

Differences in the NADPH-diaphorase positivity of the cholinergic brain stem neurons following damage of their thalamic termination field.

Following electrolesions of the anteroventral thalamic nucleus (the target structure for the NADPH-diaphorase positive axons of the cholinergic mesopontine cells, e.g. laterodorsal, pedunculopontine and lateral parabrachial nucleus) the intensity of NADPH-diaphorase staining changed drastically, but unlikely in each nucleus: it increased in the cells of the laterodorsal nucleus on the side of the lesion and decreased on the contralateral nucleus, whereas the staining intensity of the pedunculopontine and parabrachial cells remained unchanged bilaterally. In cases with small (partial) lesions of the anteroventral thalamic nucleus only lower number of heavily stained cells were observed in the laterodorsal nucleus ipsilateral to the thalamic lesion, whereas the number of slightly stained cells in the contralateral laterodorsal nucleus decreased. In contrast, not even large lesions of other thalamic nuclei, anterior or tuberal hypothalamus, zona incerta, pallidum internum, striatum or corpus callosum changed the symmetric intensity of the NADPH-diaphorase staining of the laterodorsal, pedunculopontine or lateral parabrachial nuclei. Increased intensity of the NADPH-diaphorase staining in the cells of the mamillary body was found two weeks after the electrolesions of the ipsilateral mamillo-thalamic tract or anteromedial thalamic nucleus. No degenerative changes or decrease of number of neurons in the laterodorsal tegmental nucleus in Nissl staining were detected after the electrolesions. Our data show that electrolytic lesions of target areas can lead to an upregulation of NOS expression in the parent cell bodies, provided that there is no wide collateralization as found for the pedunculopontine or parabrachial nuclei.

Animals↗

PubMed1999

Nitric oxide synthase (NADPH-diaphorase) content in brain neurons of neonatal rats after inhibitory learning and intervention into nitric oxide metabolism.

Four-day-old rat pups were taught to avoid an electrified grid under the influence of increased nitric oxide availability in brain (by a nitric oxide substrate L-arginine) that alleviated learning or decreased nitric oxide (due to the action of a blocker of nitric oxide synthase nitro-L-arginine) that impaired learning. Three hours after criteria meeting, the pups were killed for analysis of nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase content in brain cells and neuropil. In the cingulate gyrus, NADPH-diaphorase-positive staining was increased after L-arginine, but an opposite picture was observed in hippocampus and basal ganglia, i.e. an increase after the blocker nitro-L-arginine. A noteworthy accumulation of NADPH-diaphorase in hippocampal cells might be tentatively explained by the blocking effect of nitro-L-arginine not allowing NADPH-diaphorase to leave the cells. Application of L-arginine or nitro-L-arginine provoked only minor changes in the studied structures of non-learned pups with the exception of hippocampus where nitro-L-arginine increased the width of neuropil, but to a lesser degree than in learned animals. These results clearly show that both manipulations, i.e. drug application and learning, only have a significant effect on the changes in NADPH-diaphorase positivity in brain neurons.

Animals↗

PubMed1999

Brain lesion-induced alteration of selected phenotypic properties of spleen macrophages and their partial restoration in the course of foreign body reaction against intraperitoneally implanted polymers.

A lesion in the dorsoposterior part of the rat brain septum is known to exert an inhibitory effect on the delayed skin hypersensitivity and incorporation of radiolabeled thymidine into the lymphoid organs. To determine whether distinct properties of macrophages will also be modulated by this type of injury, we have focused upon the monitoring of expression of sugar receptors (lectins). In this study we show a reduction in the number of macrophages expressing carbohydrate-binding sites for asialoglycoproteins (beta-D-galactoside), alpha-D-mannoside and alpha-D-mannoside-6-phosphate in spleen macrophages after the lesion of the dorsoposterior septum of the brain in the rat. The number of ED-1+ macrophages was not influenced. The intraperitoneal injection of beads prepared from the copolymer of 2-hydroxyethyl methacrylate with dimethyl aminoethyl methacrylate (30 wt %) elevated significantly the number of ED-1+ spleen macrophages and number of macrophages with binding site(s) recognizing asialoglycoproteins and alpha-D-mannoside-6-phosphate, respectively. These results indicate that a foreign-body reaction appears to be able to mediate a phenotypic restoration of lectin expression by spleen macrophages altered by the brain lesion. It can be suggested that, for example, a probable production of cytokines by the inflammatory cells colonizing the implanted beads plays a role in this process.

Journal Article↗

PubMed1999

Experimental lesion of medial frontal cortex mediates inhibition of expression of carbohydrate-binding sites in the spleen macrophages in rat.

The fundamental concept of a neuroimmunological network is well appreciated although detailed description of the individual mechanisms has not yet been attained. In an effort to close this gap, the effect of electrolesion of the frontal medial cortex, a structure with the known "immunoreactivity", on selected phenotypic features of spleen macrophages was studied. Since sugar receptors (lectins) are pivotal for recognition, custom-made tools termed neoglycoproteins were employed to delineate any injury-induced changes of their expression. The total number of macrophages in the spleen red pulp was assessed using the ED-1 monoclonal antibody. The results showed that after lesion of the medial frontal cortex, the extent of expression of carbohydrate-binding sites in red pulp spleen macrophages significantly decreased without affecting the total number of these cells. These data intimate that distinct brain regions are involved in the control of the phenotype of macrophages in the central lymphoid organs by currently elusive biochemical mechanisms.

Animals↗

PubMed1997

The dorsal tegmentum of the pontomesencephalic junction of the rat--immunohistochemistry (choline acetyltransferase, tyrosine hydroxylase, substance P) and NADPH-diaphorase histochemistry in frontal and horizontal sections.

37 complete frontal and horizontal series of rat brain were studied to compare the distribution of choline acetyltransferase- (ChAT), tyrosine hydroxylase- (TH), substance P- (SP), calbindin D- (Calb) and NADPH-diaphorase (NADPH-d)-positive cells within the cytoarchitectonic borders of the latero-dorsal tegmental nucleus (L-D) and its neighbourhood. We found the same distribution, number and morphology of NADPH-d-positive cells and ChAT-positive cells. Rostrally, there are no borders between NADPH-d-positive cells of L-D and NADPH-d-positive cells of the lateral part of the dorsal raphe nucleus. Only a few TH-positive cells are intermingled with ChAT/NADPH-d-positive cells at the lateral border of L-D. TH-positive cells are larger or the same size as cholinergic neutrons. Locus coeruleus and its rostral part is full of TH-positive cells and their fibres run ventromedially towards L-D. Barrington's nucleus appears in double staining (ChAT and TH or NADPH-d and TH) as an empty area bordered by ChAT- or NADPH-d-positive cells of L-D and TH-positive fibres of the locus coeruleus. Some of these fibres run through the Barrington's nucleus. The shape and size of SP-positive neurons is the same as ChAT- and NADPH-d-positive neurons. SP-positive neurons are sparsely distributed in all parts of L-D, but there are only a few SP-positive cells in its medial part. About 50% of the ChAT- and NADPH-d-positive cells are also SP-positive. Results are expressed by figures in three representative frontal sections and one horizontal section through the dorsal mesopontine tegmentum.

Animals↗

PubMed1995

Topographical organization of NADPH-diaphorase positive neurons and fibres in dorsal ponto-mesencephalic tegmentum in the rat brain.

20 complete series of the rat brain, stained with cresylviolet or with the NADPH-diaphorase positive neurons demonstration method were used to compare the topographical organization of the borders of the dorsal mesopontine tegmental nuclei (latero-dorsal tegmental nucleus, dorsal and ventral tegmental nuclei of Gudden, dorsal raphe nucleus and substantia grisea centralis pontis) and to describe in detail NADPH-d positive cells and fibres in this area. We have found that topography of the cells and the borders of the nuclei were similar by the both methods, but NADPH-d histochemistry has shown the extension of NADPH-d positive cells to neighbouring structures and we would divide some nuclei into independent parts (e.g., pars medialis, ventralis and rostralis of the laterodorsal tegmental nucleus). We discussed the possibility of the projection and configuration of NADPH-d positive fibres running from the mesopontine tegmentum to the diencephalon.

Animals↗

PubMed1992

An introduction to the possible role of central nervous system structures in neuroendocrine-immune systems interaction.

The involvement of different regions of the brain in the immune response was investigated with the aid of small electrolytic lesions. The lesions were placed in such a way that they covered different areas of the brain stem, basal ganglia, but also some parts of the frontal cortex. The cellular immune response as well as DNA synthesis with the aid of labelled precursors was measured. The results suggest the possibility of the existence of three circuits. One circuit represents catecholaminergic cell group A1-7 in reticular formation, nucleus parabrachialis and central ncl. amygdalae. The second circuit represents serotonergic rapheal groups B6.8, hypothalamus and ncl. basomedialis of amygdala. The third circuit represents ncl. amygdalae and the medial part of frontal cortex, namely the cingulate cortex area 1-2. The close correlation between the changes of the immune response and the CNS activity was also investigated in the experiments with immunosuppressed and immunostimulated animals by measuring of the turnover of some neurotransmitters but also by recording electrocephalographic activity.

Animals↗

PubMed1992

Changes in the configuration and the dimensions of the fossa hypophysealis in the rat (Rattus rattus norvegicus) dependent on the age, weight and individual size of the skull.

The aim of our work was to describe the fossa hypophysealis in the most common laboratory animal--in the rat, to measure its dimensions, to determine its stereotactic coordinates and to find the dependence of these coordinates on the age, weight and individual size of the skull in different rats. From this measurement we obtained data on the growth and possible shifts of the fossa hypophysealis but also found data facilitating the selection of animals to stereotactic operations so that the hit of the hypophysis be the most probable. There are suitable coordinates for bilaterally stereotactic intervention into the middle female rats hypophysis in conclusions of our work.

Animals↗

PubMed1990

Thalamic afferents from the brain stem. An experimental study using retrograde single and double labelling with HRP and iron-dextran in the rat. I. Medial and lateral reticular formation.

The reticulo-thalamic projection of the rat was studied in single and double experiments using 51 injections of HRP and/or iron-dextran. The medial reticular formation (excluding the ncl. pedunculo-pontinus, subncl. compactus, see Part II) sends out projections to the ncll. intralaminares (IL), ncl. mediodorsalis (MD), ncl. ventralis medialis (VM), ncl. ventralis lateralis (VL), ncl. ventralis basalis (VB) and ncl. posterior (PO) of the thalamus. The mesencephalic RF (ncl. cuneiformis and ncl. subcuneiformis) projects to all the above mentioned nuclei. The rhombencephalic RF (ncl. pontis oralis, ncl. pontis caudalis, ncl. gigantocellularis et paragigantocellularis dorsalis et lateralis) projects to the posterior IL (ncl. parafascicularis and ncl. centromedianus) and to the MD, pars paralaminaris. The pontine RF (ncl. pontis oralis et caudalis) projects to the posterior IL and to the medial part of the ncl. parafascicularis. The RF of the pons and the upper oblongata projects to the VL, VB and PO. The lateral RF (ncl. parvocellularis) projects solely from the tiers around the ncl. n. VII. to the posterior IL in what is a scanty projection. We found no connections projecting from the medial or lateral RF to the midline nuclei, to the lateral nuclei or to the ncl. commissurae posterioris; the projection to the ncl. reticularis thalami was left unstudied. The reticulo-thalamic pathways exhibit marked laterality. The mesencephalic RF projects to the thalamus in what is pronounced ipsilateral predominance, the pontine RF in ipsilateral predominance, the upper oblongata RF equally ipsi- and contralaterally, and the lower oblongata RF with a predominance of the contralateral component. Collateralization (double labelled cells) was found projecting solely to the IL and MD regions. It was both ipsilateral and contralateral. The discoveries included the topographical organization of the reticulo-thalamic projection: a major antero-posterior in the rhombencephalon and a mediolateral in the projections from the mesencephalon and from the pons. The most substantial projection was found aiming at the posterior IL nuclei (ncl. parafascicularis-centrum medianum), a less substantial one to the ventral and posterior nuclei, and the scantiest to the anterior IL nuclei (ncl. paracentralis, ncl. centralis lateralis).

Animals↗

PubMed1990

Thalamic afferents from the brain stem. An experimental study using retrograde single and double labelling with HRP and iron-dextran in the rat. II. Nucleus laterodorsalis and subnucleus compactus nuclei pedunculo-pontini.

The reticulo-thalamic projection arising from the ncl. latero-dorsalis and from the subncl. compactus nuclei pedunculo-pontini was studied in single and double experiments using 51 injections of HRP and/or iron-dextran. The ncl. latero-dorsalis projects to the midline nuclei, to the ncl. mediodorsalis and to the ncl. ventralis lateralis, and, together with the subncl. compactus, also to the anterior, intralaminar nuclei, to the ncl. ventralis basalis and ncll. posteriores. Part of the substantia grisea centralis pontis adjoining the oral pole of the ncl. latero-dorsalis sends out fibres throughout the region of the above listed nuclei while projecting only scantily to the anterior nuclei and to the ventrobasal complex. The projection from the ncl. laterodorsalis has a major contralateral component (about one third of the labelled cells) whereas the contralateral component arising from the subncl. compactus is very scanty. We found no topographic arrangement in the projection (though there were signs of a crude mediolateral organization). The projection, mainly from the ncl. latero-dorsalis, shows relatively dense collateralization (double-labelled cells): ipsi- as well as contralaterally to the intralaminar nuclei, or collaterals to the ipsilateral intralaminary nuclei and, at the same time, to the contralateral ncl. mediodorsalis. A similar, albeit smaller collateralization, was also seen in the ncl. pedunculo-pontinus, its subncl. compactus: ipsilateral collateralization between the anterior and intralaminar nuclei or between the anterior and posterior intralaminar nuclei of the ipsilateral side.

Animals↗

PubMed1989

Parabrachial nuclear complex. A comparative study of its cytoarchitectonics in birds and some mammals including man.

The cytoarchitectonic structure of the ncl. parabrachialis of 20 bird species, 17 mammals and man was studied in sections stained with cresyl violet. This comparative study showed the six cytoarchitectonic subnuclei of the ncl. parabrachialis (subncl. medialis, dorsomedialis, dorsalis, lateralis, dorsolateralis and ventralis) to be unevenly developed in the vertebrates under study. The degree of development of the subnuclei was tabulated to bring out the developmental trends of the ncl. parabrachialis in different groups of vertebrates. Only three of the six subnuclei were found enlarged in higher primates and in man--the subncl. dorsolateralis, lateralis and medialis, the latter two (subncl. lateralis and medialis) being also larger in insectivores. The most primitive structure is that of the subncl. ventralis with features very much like those of a small-cell reticular formation. Cytoarchitectonically speaking, the parabrachial subnuclei appear to be of polyphyletic origin: the medial and dorsomedial subnuclei being close to the substantia grisea centralis, the ventral subnucleus to the small-cell lateral reticular formation, and the lateral and dorsolateral subnuclei to the ncl. pedunculo-pontinus.

Animals↗