Differential Behavioral Responses to\ud Cocaethylene of Long-Evans and\ud Sprague-Dawley Rats: Role of Serotonin

Cocaethylene is a neuroactive metabolite derived from the concurrent consumption of cocaine and ethanol. The effects of cocaethylene on locomotor activity, stereotypy, and rearing in Long-Evans and Sprague-Dawley rats were compared.A single cocaine injection (molar equivalent of 60 μmol/kg cocaethylene, intraperitoneal) elicited a robust series of motor output behaviors, including locomotion, stereotypy, and rearing over a 30-minute testing period in Long-Evans rats. In contrast, cocaethylene administration,\ud under comparable testing conditions, produced no significant changes in locomotor and investigatory behaviors. Because cocaethylene has relatively little impact on serotonin (5-HT) reuptake as opposed to reuptake of dopamine, we pretreated Long-Evans rats with fluoxetine (10 mg/kg; IP), a selective 5-HT reuptake inhibitor. Fluoxetine profoundly augmented cocaethylene-stimulated behaviors in this rat phenotype. To examine whether other rat strains exhibit a similar response to cocaethylene, Sprague-Dawley rats were injected (IP) with cocaethylene and their behavior patterns monitored over a 30-minute testing period. Cocaethylene produced marked locomotor and exploratory behaviors in this strain, suggesting therefore that Long-Evans and Sprague-\ud Dawley rats differ in their response to cocaethylene. To relate these behavioral differences to possible structural differences in the neuronal density of dopaminergic or\ud serotonergic neurons, Long-Evans and Sprague-Dawley brains were evaluated for tyrosine hydroxylase and 5-HT immunocytochemistry. No gross morphological differences\ud in neuronal architecture or density were found in the ventral tegmental area or dorsal raphe nucleus of the two rat phenotypes. These results indicate that two commonly used rat strains show a differential response to cocaethylene and the neurochemical basis for this behavioral difference may be related to synaptic 5-HT bioavailability

Frontostriatal deficit in Motor Neuron Disease/Amyotrophic Lateral Sclerosis (MND/ALS)

So far, cognitive derangements in MND/ALS have not been widely studied. Nevertheless, it seems that in subgroups of patients cognitive functions are impaired in different degree, so that often at least two sub-types of the syndrome are reported: Motor Neuron Disease/Amyotrophic Lateral Sclerosis/Dementia Syndrome (MND/ALS/DS) and Motor Neuron Disease/Amyotrophic Lateral Sclerosis/ Aphasia Syndrome (MND/ALS/AS. A third subtype showing both symptoms of cognitive impairment may be identified in subgroups of patients and denominated Motor Neuron Disease/Amyotrophic Lateral Sclerosis/Dementia-Aphasia Syndrome (MND/ALS/DAS). Frontostriatal system is reported as a network heavily damaged in MND/ALS/DS, MND/ALS/AS, MND/ALS/DAS. The system is plausibly responsible of motor skills and verbs production, hence to become aware of a possible frontostriatal deficit in subgroup of MND/ALS patients might consent us to link at the brain level (motor) action and verbs and possibly ideomotor praxia and verbs. We have used Goal-Oriented Perception Task (GOPT) and Action Fluency Task (AFT) in order to detect with some accuracy impairments related to gestaltic analysis directed toward a goal, and verb retrieval deficits possibly underlying executive system dysfunction that destabilizes the ability to mentally coordinate the information associated with a verb. These tests should consent to detect possible frontostriatal derangements. We have tested 10 MND/ALS patients and 10 healthy subjects matched fore age, sex and laterality. AFT showed that 3 out of 6 patients are heavily impaired in this test (6.3 (mean) verbs generated vs 13.3 of the control group). GOPT detected a remarkable impairment in all patients: p=0.0021 (grammatical side), p=0.0002 (perceptual side). Reported frontostriatal deficit in MND/ALS seems confirmed by this study, and probably it is more easily detected by GOPT than by AFT

Effects of cocaethylene on dopamine and serotonin synthesis in Long–Evans and Sprague–Dawley brains

We examined the behavioral and neurochemical effects of cocaethylene treatment in Long–Evans (�LE). and Sprague–Dawley� (SD) rats. Cocaethylene-induced behaviors were significantly less in LE rats. Cocaethylene caused an inhibition of dopamine synthesis in the caudate nucleus and nucleus accumbens that was equivalent in both rat lines. Serotonin synthesis was also suppressed by cocaethylene treatment, however this phenomenon was less pronounced when compared with the effects on dopamine synthesis

Dopaminergic, glutamatergic but not opioidergic mechanisms mediate induction of FOS-like protein by cocaethylene

Cocaethylene is a psychoactive metabolite formed\ud during the combined consumption of cocaine and ethanol. As\ud this metabolite has many properties in common with cocaine, it is conceivable that cocaethylene administration may induce the activity of nuclear transcription factors that regulate the expression of late-response genes. Therefore, the temporal induction of FOS-like protein in rat brain was examined following IP administration of 60 mmol/kg cocaethylene. Immunoreactivity for the protein was detectable at 1 h in striatal neurons and had virtually disappeared 6 h after drug treatment. Administration of\ud specific dopaminergic (SCH-23390; 0.5 mg/kg) and glutamatergic (MK-801; 1 mg/kg) receptor antagonists prior to cocaethylene indicated a significant role for dopamine (D1) and Nmethyl-D-aspartate receptor subtypes in mediating the nuclear induction of the aforementioned transcription factor protein. In contrast, no significant effects on FOS-like protein in discrete neurons of the caudate putamen were found when spiradoline (U-62066), a kappa opioid-receptor agonist, was administered either IP (10 mg/kg) or directly (50 nmol) into the brain parenchyma. In addition, we uncovered a differential sensitivity of Long–Evans rats to the behavioral effects of cocaethylene, with the psychoactive metabolite producing significantly less behavioral activity (e.g., locomotion, rearing, and continuous sniffing)than that produced by cocaine (molar equivalent of 60 mmol/kg cocaethylene). These findings indicate both common and disparate effects of cocaethylene and its parent compound, cocaine, on receptor pathways that regulate target alterations in gene expression and drug-induced motor behavior

Neural Mechanisms for Information Compression by Multiple Alignment, Unification and Search

This article describes how an abstract framework for perception and cognition may be realised in terms of neural mechanisms and neural processing. This framework — called information compression by multiple alignment, unification and search (ICMAUS) — has been developed in previous research as a generalized model of any system for processing information, either natural or artificial. It has a range of applications including the analysis and production of natural language, unsupervised inductive learning, recognition of objects and patterns, probabilistic reasoning, and others. The proposals in this article may be seen as an extension and development of Hebb’s (1949) concept of a ‘cell assembly’. The article describes how the concept of ‘pattern’ in the ICMAUS framework may be mapped onto a version of the cell assembly concept and the way in which neural mechanisms may achieve the effect of ‘multiple alignment’ in the ICMAUS framework. By contrast with the Hebbian concept of a cell assembly, it is proposed here that any one neuron can belong in one assembly and only one assembly. A key feature of present proposals, which is not part of the Hebbian concept, is that any cell assembly may contain ‘references’ or ‘codes’ that serve to identify one or more other cell assemblies. This mechanism allows information to be stored in a compressed form, it provides a robust mechanism by which assemblies may be connected to form hierarchies and other kinds of structure, it means that assemblies can express abstract concepts, and it provides solutions to some of the other problems associated with cell assemblies. Drawing on insights derived from the ICMAUS framework, the article also describes how learning may be achieved with neural mechanisms. This concept of learning is significantly different from the Hebbian concept and appears to provide a better account of what we know about human learning

In the Beginning Was the Verb: The Emergence and Evolution of Language Problem in the Light of the Big Bang Epistemological Paradigm.

The enigma of the Emergence of Natural Languages, coupled or not with the closely related problem of their Evolution is perceived today as one of the most important scientific problems. \ud The purpose of the present study is actually to outline such a solution to our problem which is epistemologically consonant with the Big Bang solution of the problem of the Emergence of the Universe}. Such an outline, however, becomes articulable, understandable, and workable only in a drastically extended epistemic and scientific oecumene, where known and habitual approaches to the problem, both theoretical and experimental, become distant, isolated, even if to some degree still hospitable conceptual and methodological islands. \ud The guiding light of our inquiry will be Eugene Paul Wigner's metaphor of ``the unreasonable effectiveness of mathematics in natural sciences'', i.e., the steadily evolving before our eyes, since at least XVIIth century, \ud ``the miracle of the appropriateness of the language of mathematics for the formulation of the laws of physics''. Kurt Goedel's incompleteness and undecidability theory will be our guardian discerner against logical fallacies of otherwise apparently plausible explanations. \ud John Bell's ``unspeakableness'' and the commonplace counterintuitive character of quantum phenomena will be our encouragers. And the radical novelty of the introduced here and adapted to our purposes Big Bang epistemological paradigm will be an appropriate, even if probably shocking response to our equally shocking discovery in the oldest among well preserved linguistic fossils of perfect mathematical structures outdoing the best artifactual Assemblers

Media Presence and Inner Presence: The Sense of Presence in Virtual Reality Technologies

Abstract. Presence is widely accepted as the key concept to be considered in any research involving human interaction with Virtual Reality (VR). Since its original description, the concept of presence has developed over the past decade to be considered by many researchers as the essence of any experience in a virtual environment. The VR generating systems comprise two main parts: a technological component and a psychological experience. The different relevance given to them produced two different but coexisting visions of presence: the rationalist and the psychological/ecological points of view. The rationalist point of view considers a VR system as a collection of specific machines with the necessity of the inclusion \ud of the concept of presence. The researchers agreeing with this approach describe the sense of presence as a function of the experience of a given medium (Media Presence). The main result of this approach is the definition of presence as the perceptual illusion of non-mediation produced by means of the disappearance of the medium from the conscious attention of the subject. At the other extreme, there \ud is the psychological or ecological perspective (Inner Presence). Specifically, this perspective considers presence as a neuropsychological phenomenon, evolved from the interplay of our biological and cultural inheritance, whose goal is the control of the human activity. \ud Given its key role and the rate at which new approaches to understanding and examining presence are appearing, this chapter draws together current research on presence to provide an up to date overview of the most widely accepted approaches to its understanding and measurement

Image Encryption Based on Diffusion and Multiple Chaotic Maps

In the recent world, security is a prime important issue, and encryption is one of the best alternative way to ensure security. More over, there are many image encryption schemes have been proposed, each one of them has its own strength and weakness. This paper presents a new algorithm for the image encryption/decryption scheme. This paper is devoted to provide a secured image encryption technique using multiple chaotic based circular mapping. In this paper, first, a pair of sub keys is given by using chaotic logistic maps. Second, the image is encrypted using logistic map sub key and in its transformation leads to diffusion process. Third, sub keys are generated by four different chaotic maps. Based on the initial conditions, each map may produce various random numbers from various orbits of the maps. Among those random numbers, a particular number and from a particular orbit are selected as a key for the encryption algorithm. Based on the key, a binary sequence is generated to control the encryption algorithm. The input image of 2-D is transformed into a 1- D array by using two different scanning pattern (raster and Zigzag) and then divided into various sub blocks. Then the position permutation and value permutation is applied to each binary matrix based on multiple chaos maps. Finally the receiver uses the same sub keys to decrypt the encrypted images. The salient features of the proposed image encryption method are loss-less, good peak signal-to-noise ratio (PSNR), Symmetric key encryption, less cross correlation, very large number of secret keys, and key-dependent pixel value replacement.Comment: 14 pages,9 figures and 5 tables; http://airccse.org/journal/jnsa11_current.html, 201