1,721,386 research outputs found
Fattori comuni a colloquio interiore, altruismo, condizioni subcliniche di malattie mentali alla luce di evidenze biologiche e intuizioni di artisti
No full textIt is suggested that some unique human mental capabilities on one hand have been
crucial for the evolutionary success of Homo Sapiens and for the development of his
complex and so different social organizations, on the other hand have represented a
new target for mental diseases. Furthermore, it is put forward a new concept to describe
some cases of evolutionary maladaptation, namely the “mis-exaptation” concept, which
is derived from the Gould Vrba concept of exaptation (Gould & Vrba, 1982). The special
human mental capability considered in the present paper is the “inner speech”. As
it will be shown, too an intense inner speech not only is an obstacle to act (see below,
Shakespeare and Leopardi), but it may be also a fertile soil where mental disturbances
can germinate.
It will also be discussed the possible evolutionary value for the population of the
appearance in some subjects of mis-exadaptive traits related to the inner speech, namely
the altruistic behaviour and some subclinical forms of mental diseases. As a matter of
fact, data will be reported demonstrating a possible link between some cases of borderline
schizophrenia and bipolar depression with creativity.
Finally, a possible solution for the evolutionary-genetic paradox posed by altruism
and schizophrenia will be suggested on the basis of the cryptic genetic repertoire, which
is likely present in the Homo Sapiens and has a fundamental role for evolvability.
Whenever possible, a parallel analysis will be carried out between bio-medical data
and hypotheses and intuitions of philosophers and great novelists
A simple mathematical model of cooperativity in receptor mosaics based on the "symmetry rule"
No full textThe phenomenon of receptor–receptor interactions was hypothesized about 20 years ago. It has been demonstrated by now that
receptor–receptor interactions between G-protein coupled receptors (GPCRs) occur at plasma membrane level and result in the
reciprocal modulation of their binding characteristics (i.e., cooperativity). One of the most important feature of this phenomenon
is the concept of cluster of receptors, or receptor mosaic (RM). However, no proper mathematical approach has still been available
to characterize RMs as far as their receptor composition, receptor topography and order of receptor activation inside the RM.
This paper tries to fill the gap.
A simple mathematical approach to the cooperativity in RMs formed by dimers of identical receptors and/or by iso-receptors is
proposed. To this aim the so-called “symmetry rule” has been considered. This approach allows to describe by means of a simple
energy function the effects of receptor composition (number of dimers), spatial organisation (respective location of the dimers) and
order of activation (order according to which the single receptors are ligated) on the integrative cooperativity (index) of the RMs
Development of computer-assisted simulation procedure to analyze receptor modulatory processes.
No full textMORPHOMETRIC EVALUATION OF POPULATIONS OF NEURONAL PROFILES (CELL-BODIES, DENDRITES, AND NERVE-TERMINALS) IN THE CENTRAL-NERVOUS-SYSTEM
No full textMorphometric techniques have been developed to quantitatively characterize groups of transmitter-identified neuronal profiles, such as cell groups, dendrite and nerve terminal fields. These morphometric techniques will be illustrated by introducing some general tools for image analysis which can be considered as a background for the present specific applications. The following methods have been included: (1) methods to identify and quantitatively characterize, from both numerical and geometrical standpoints, groups of profiles in a two- and three-dimensional frame; (2) methods to evaluate the evenness of a certain distribution of profiles in the plane; (3) methods to identify subgroups of profiles based on their different spatial or optical density; and (4) methods to compare the distributions of two or more groups of profiles. The applications of these general tools to some neuroanatomical problems, such as cell group definition and description, have been illustrated. Practical examples performed on immunocytochemical preparations of neuronal profile populations are also given. Finally, the potentiality of numerical classification to classify and compare morphometric data has been shown. As an example, numerical classification methods have been applied to the morphometric and microdensitometric analysis of adrenaline/neuropeptide Y costoring neuronal systems of the brainstem in adult and aged rats
Increases of Sulphated Glycoprotein 2 mRNA levels in the rat brain after transient forebrain ischemia or partial mesodiencephalic hemitransection
No full textTheoretical Considerations on the Topological Organization of Receptor Mosaics
No full textThe concept of Receptor Mosaic (RM) is discussed; hence the integrative functions of the assemblage of G-protein coupled receptors physically interacting in the plane of the plasma membrane. The main focus is on a hetero-trimer of G-protein coupled receptors, namely the A2A-D2-CB1 receptor trimer. A bioinformatics analysis was carried out on the amino acid sequence of these receptors to indicate domains possibly involved in the receptor-receptor interactions. Such a bioinformatic analysis was also carried out on the RM formed by mGLU R5, D2 and A2A. The importance of topology, i.e., of the reciprocal localisation of the three interacting receptors in the plan of the membrane for the RM integrative functions is underlined. However, it is also pointed out that this fundamental aspect still waits techniques capable of an appropriate investigation. Finally, it is discussed how RM topology can give hints for a structural definition of the concept of hub receptor. Thus, just as in any network, the receptor operating as a hub is the one that in the molecular network formed by the receptors has the highest number of inputs
Functional roles of three cues that provide non-synaptic modes of communication in the brain: electromagnetic field, oxygen and carbon dioxide
No full textCyclic nucleotide- and calcium-dependent protein phosphorylation in rat pineal gland: physiological and pharmacological regulation.
No full textReceptor-receptor interactions, receptor mosaics, and basic principles of molecular network organization - Possible implications for drug development
No full textThe phenomenon of receptor-receptor interactions was hypothesized by Agnati and Fuxe in the 1980s, and
several indirect proofs were provided in the following years by means of in vitro binding experiments and in
vivo experiments in physiological and pathological animal models. This paper aims to outline some of the most
important features and consequences of this phenomenon in the frame of the structural and functional aspects
of molecular networks. In particular, the concepts of receptor mosaic (RM), and of horizontal and vertical
molecular networks (HMNs, VMNs, respectively) are illustrated. To discuss some aspects of the functional
organization of molecular networks, not only new data on protein-protein interactions but also the biochemical
mechanism of cooperativity will be used. On this basis, some theoretical deductions can be drawn that allow
a tentative classification of the RMs and the proposal of the extension of the concept of branching point introduced
for enzymes to the possible switching role of some RMs in directing signals to various VMNs. Finally, the
cooperativity phenomenon and the so-called symmetry rule will be used to introduce a proper mathematical
approach that characterizes RMs as to their receptor composition, receptor topography, and order of receptor
activation inside the RM. These new data on G protein–coupled receptors and molecular network organization
indicate possible new approaches for drug development
Central Nervous System and computation
No full textComputational systems are useful in neuroscience in many ways. For instance, they may be used to construct maps of brain structure and activation, or to describe brain processes mathematically. Furthermore, they inspired a powerful theory of brain function, in which the brain is viewed as a system characterized by intrinsic computational activities or as a “computational information processor.” Although many neuroscientists believe that neural systems really perform computations, some are more cautious about computationalism or reject it. Thus, does the brain really compute? Answering this question requires getting clear on a definition of computation that is able to draw a line between physical systems that compute and systems that do not, so that we can discern on which side of the line the brain (or parts of it) could fall. In order to shed some light on the role of computational processes in brain function, available neurobiological data will be summarized from the standpoint of a recently proposed taxonomy of notions of computation, with the aim of identifying which brain processes can be considered computational. The emerging picture shows the brain as a very peculiar system, in which genuine computational features act in concert with noncomputational dynamical processes, leading to continuous self-organization and remodeling under the action of external stimuli from the environment and from the rest of the organism
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