Acta morphologica Neerlando-Scandinavica最新文献

{"title":"Principles of biological comparison.","authors":"W J Bock","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The problems of comparative analyses in biology have been discussed, showing that a single comparative method does not exist. Several principles of comparison are elucidated, which include that comparisons do not have to possess a phylogenetic basis, can be horizontal or vertical, and can be genetic or nongenetic. Biological comparisons can be grouped roughly into historical and nonhistorical ones. Historical comparisons depend on the details of evolutionary theory, and include: (a) comparisons on which phylogenies and classifications are based; and (b) comparative studies using these phylogenies and classifications. Nonhistorical comparisons require pertinent nomological relationships between two or more variables, and include: (a) comparisons between variables used to elucidate these law-like relationships; and (b) comparisons in which unknown properties of one variable are deduced from the known properties of other variables - extrapolations made in biology.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"27 1-2","pages":"17-32"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13823227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The shape of the mandible in the domestic sheep: a biomechanical analysis using EMG as an estimator of muscle force.","authors":"H J de Jongh,&nbsp;R Dantuma,&nbsp;H M Sluijsmans","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Analysis of the maximal loads to which a skeletal element is subjected in vivo offers attractive possibilities of explaining the shape of the element. The underlying assumption is that the element will be constructed in such a way that deformations (strains) which result from mechanical stress will not exceed certain limits and that stresses will be evenly distributed. The sheep mandible shows a number of characteristic morphological features that invite this kind of explanation. We investigated the patterns of activity of the masticatory musculature by multichannel electromyography, expressing the activity of any particular muscle during a given interval as a percentage of the highest activity recorded for the muscle in question. In combination with data on the physiological cross sections of the muscles, which provide indications of the maximal forces which can be exerted by the muscles, three-dimensional patterns of relative muscular forces acting on the mandible can be constructed for successive stages of a masticatory cycle. No absolute forces can be measured or even estimated by this technique. A two-dimensional finite element model of the mandible was designed, by means of which predictions of stress and strain resulting from the muscular loading can be made. Calculations were based on the highest loads that occurred, during the power stroke of rumination. It is concluded that mechanical loading of the mandible provides a partial explanation of the form, and that a more satisfactory model should include other than purely mechanical influences.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"27 1-2","pages":"63-73"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13954346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A theoretical reflexion on some crucial concepts in functional morphology.","authors":"W Verraes","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>In this paper the author comments on some basic terms used in functional morphology, such as \"form\", \"function\", \"biological role\" and \"optimum\". A distinction between \"function\" and \"action\" is made. It is defended that causal morphology explains the form-parameters, while functional morphology helps to understand them. Because in our view understanding (answers to the question \"why?\") the form-parameters is the essence of functional morphology, the descriptive analysis of movements (which answers to \"how?\") is not the final purpose.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"27 1-2","pages":"75-81"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13954347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constructional constraint and its ecomorphological implications.","authors":"C D Barel,&nbsp;G C Anker,&nbsp;F Witte,&nbsp;R J Hoogerhoud,&nbsp;T Goldschmidt","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>This paper analyses the role of constructional morphology in explaining the limitations on the interactions between an organism and those factors in its environment which are potentially relevant to its inclusive fitness. Constructional morphology deals with the relations between functionally relevant anatomical units (apparatuses or functional components) and thereby demonstrates what quantitative and qualitative constraints there are on combining units necessary for environmental interactions. It is argued that investigations on the relations between form and environment (ecological morphology) should (1) consider three types of relations: form-form, form-function and function-environment factor, (2) include behavioral and physiological ecology and (3) not be limited to a particular stage, but include as much of ontogeny as possible.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"27 1-2","pages":"83-109"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13954348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A functional explanation for a sequence of developmental events in the carp. The absence of gills in early larvae.","authors":"J W Osse","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The animal body is composed of structural elements which can be characterized by their size, position, external form, internal structure and their participation in functions. Their presence is taken for granted. The ontogenetic sequence of development of functional systems in fish shows an early absence of gills although effective and fast suction feeding movements are already found in 6 mm larvae. Calculations of the oxygen diffusion boundary layer in these larvae which would be present when oro buccal ventilation would occur show that no effective gill respiration is possible. The early absence and later development and use of gills for gas exchange reflects the changing demands of functions.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"27 1-2","pages":"111-8"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13955880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Innervation pattern in jaw muscles of various mammalian chewing types.","authors":"G H Schumacher","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The intramuscular nerve branches of the masticatory muscles were investigated in different mammalian species such as Canis familiaris, Capreolus capreolus, Capra hircus africans, Bos primigenius forma taurus, Myocastor coypus MOLINA 1782, Sus scrofa domestica, Pan troglodytes, Homo sapiens. The ramifications of the nerves form a specific pattern that is adapted to the specialised muscle structures in all mammalian chewing type. The innervation pattern is fully consistent with the infrastructures of the muscles which are already fixed at birth. Differences between the ramification pattern in comparable muscles in different chewing types are only minor, not fundamental.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"27 1-2","pages":"139-47"},"PeriodicalIF":0.0,"publicationDate":"1989-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"13954344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synaptic and non-synaptic communication in the brain: morphological, physiological and behavioral aspects. Proceedings of a workshop. Nijmegan, The Netherlands, November 29, 1988.","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"26 2-3","pages":"65-190"},"PeriodicalIF":0.0,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14045169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synaptic and nonsynaptic release of neuromediators in the central nervous system.","authors":"P Buma","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Different types of release site were studied ultrastructurally with tannic acid and immunohistochemical techniques in the central nervous system (CNS) of the invertebrate pond snail Lymnaea stagnalis and in two neuromediator rich core regions in the CNS of the rat, viz., the median eminence (ME) and the mesencephalic central grey substance (MCG). In the CNS of the snail, release of the contents of the secretory granules could be clearly demonstrated in (1) neurohaemal axonterminals, (2) synapses and (3) in nonsynaptic release sites: neuronal processes without morphological synaptic specializations. In the ME, release of secretory products by exocytosis was found in neurohaemal axonterminals in the external part of the palisade layer and in nonsynaptic release sites in all other layers of the median eminence. It was found that oxytocine and vasopressin were released by exocytosis into the extracellular space from such (preterminal) nonsynaptic release sites. Serial section analysis revealed three types of fibre in the MCG, viz. (1) varicose fibres that made synaptic contacts with MCG dendrites on every varicosity, (2) fibres with two types of varicosity, viz. synapse-bearing varicosities and varicosities without synaptic specializations, and (3) varicose fibres without any synaptic specializations. It has been discussed that the nonsynaptic release sites in the CNS of the snail Lymnaea stagnalis, and the nonsynaptic varicosities in the rat brain are the morphological correlates of nonsynaptic communication in the CNS. The results further indicate that particular peptidergic neuromediators are released from such nonsynaptic varicosities, and may reach via the extracellular space receptors located at some distance.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"26 2-3","pages":"81-113"},"PeriodicalIF":0.0,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14045170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Issues involved in the transmission of chemical signals through the brain extracellular space.","authors":"C Nicholson","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Two classes of substances exist within the extracellular space: energetic and informational. Examples of the former are glucose, dissolved oxygen and CO2 while the latter include excitatory amino acids, cathecholamines and opiates. The simple ions Na+ and Cl- are generally associated with energetic processes while extracellular K+ and Ca2+ tend to be informational in function. Local release of an informational substance brings about a concentration gradient that causes the substance to be dispersed in the extracellular space by diffusion. This process is modified relative to a free aqueous medium by the constraints of volume fraction, tortuosity and uptake. Volume fraction is defined simply as the fraction of a brain region that is extracellular. If a given quantity of substance is released into a region with a reduced volume fraction then the substance will reach a higher concentration than it would in a free medium. Tortuosity is related to the increase in the path length of the random walk of a diffusing particle due to the necessity to navigate around cellular obstructions. Tortuosity manifests itself as a decrease in the diffusion coefficient. Uptake represents the movement of a substance from the extracellular space to the intracellular. Since initially a concentration gradient exists in this direction and all membranes have some permeability some concentration-dependent uptake always occurs. In addition there exist specific carrier-mediated uptake processes for some substances such as amino acids or catecholamines. In some regions the dispersal process can be dominated by uptake rather than diffusion. While volume fraction, tortuosity and uptake have all been demonstrated by a technique based on the use of radiolabels and other methods, these classical techniques have limited spatial and temporal resolution. The advent of methods based on micro-injection of substances by iontophoresis or pressure and subsequent detection with ion-selective microelectrodes (ISMs) or voltammetric microsensors (VMs) has opened a new window onto the dynamic local behavior of the extracellular space. In the last decade our laboratory and others have studied the migration of the test substances tetramethylammonium, tetraethylammonium, AsF6- and alpha naphthalene sulfonate, the endogenous ions K+ and Ca2+, the epileptogenic agent penicillin and the neurotransmitter dopamine. These studies have been carried out on the cerebellum and some other regions in a variety of species that include rat, turtle, skate and an intervertebrate, the cuttlefish.(ABSTRACT TRUNCATED AT 400 WORDS)</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"26 2-3","pages":"69-80"},"PeriodicalIF":0.0,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14045171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synaptic and non-synaptic striatal dopamine D2 receptors: possible implications in normal and pathological behaviour.","authors":"J Korf,&nbsp;L D Loopuijt","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Various levels of organisation in the central nervous system can be distinguished, ranging from the molecular, the cellular, the multicellular and the neuronal system level. The relationship between receptor function and behaviour is focussed to the dopamine D2 type receptor of the striatal complex in relation to extrapyramidal and limbic systems. In the striatal complex a striosomal and a matrix compartment can be distinguished. The matrix compartment can be considered as a part of the extrapyramidal system and is innervated by the motor cortex and by the dopaminergic neurons of the ventral tegmental, the dorsal substantia nigra and the retrorubral area. This compartment has a relatively high density of D2 receptors. The striosomes are innervated by e.g. the prelimbic cortex and dopamine neurones of the ventral part of the substantia nigra; here the density of D2 receptors are lower. Under normal conditions most of the D2 receptors are occupied by endogenous dopamine, and postsynaptic (e.g. cholinergic) function is therefore sensitive to antagonists; e.g. antipsychotics. Exposure to drugs such as amphetamine produces a substantial overflow of dopamine from nerve terminals leading to the activation of remote dopamine receptors, that may belong to the system that normally is not influenced by these nerve terminals (defined here as extra synaptic receptor activation). A loss of the normal spatial-temporal relationships may also occur during L-DOPA therapy in Parkinson's disease. In this illness, due to degeneration of dopaminergic innervation, several dopamine receptors have become non-synaptic. In these states of intoxication the normal spatial/temporal organization is lost and such a loss may contribute to behavioural impairments.</p>","PeriodicalId":75392,"journal":{"name":"Acta morphologica Neerlando-Scandinavica","volume":"26 2-3","pages":"177-90"},"PeriodicalIF":0.0,"publicationDate":"1988-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"14045168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}