Funktion og udvikling af menneskelig bevidsthed

Human consciousness may be described as a representational system consisting of 3 interacting levels: (1) The presentation, which is the part of the physical reality that influences the human senses. (2) The representation, which is defined by; (2a) a selective mental reflection of the presentation; (2b) a mental reflection of stored phenomenafrom long term memory; (2c) a selective mental reflection of the presentation in relation to stored phenomena from long term memory. (3) The meta-representation, which is an abstraction and/or an expansion of an original representation. It is argued that the function of the human representational system must be understood in relation to problem solving. New evidence concerning the mental and culturel level of chimpanzees is examined in relation to an understanding of the phylogenetic development of the human representational system. The basic assumption is that the chimpanzees do possess a representational system, which is different in capacity from the human representationalsystem. Evidence concerning the mental and cultural level of chimpanzees is further extended in the light of archeological findings, which indicate that the development of the capacity of the human representational system is related directly to phylogenetic development of larger brain size.Den menneskelige bevidsthed kan beskrives som et repræsentationelt system. Dette 3-delte system består af (1) Præsentationen, som er den del af den fysiske virkelighed, der registreres af menneskets sanser. (2) Repræsentationen, som defineres ved; (2a) en selektiv mental genspejling af præsentationen; (2b) en mental genspejling af lagrede fænomener fra langtidshukommelsen eller; (2c) en selektiv mental genspejling af præsentationen i relation til lagrede fænomener fra langtidshukommelsen. (3) Meta-repræsentationen, der er en abstraktion og/eller udvidelse af en oprindelig repræsentation. Funktionen af det menneskelige repræsentationelle system søges argumenteret for i relation til problemløsning. Nye vidnesbyrd om chimpansers mentale og kulturelle formåenundersøges i relation til en forståelse af en fylogenetisk udvikling af menneskets repræsentationelle system. Den basaleantagelse er, at chimpanserne besidder et repræsentationelt system, som adskiller sig fra menneskets repræsentationelle system via en forskel i kapacitet. Vidnesbyrd om chimpansers mentale og kulturelle formåenudbygges videre i lyset af arkæologiske fund, som tyder på udvikling af en repræsentationel systemkapacitet i direkte relation til fylogenetisk udvikling af større hjernemasse

Oxidative damage and chemokine production dominate days before immune cell infiltration and EAE disease debut

BACKGROUND: Multiple sclerosis is widely accepted as an inflammatory disease. However, studies indicate that degenerative processes in the CNS occur prior to inflammation. In the widely used animal model experimental autoimmune encephalomyelitis (EAE), we investigated the significance of degenerative processes from mitochondrial membrane potentials, reactive oxidative species, cell death markers, chemokines, and inflammatory cell types in brain, spinal cord, and optic nerve tissue during the effector phase of the disease, before clinical disease was evident. METHODS: Sixty-two rats were placed in eight groups, n = 6 to 10. Four groups were immunized with spinal cord homogenate emulsified in complete Freund’s adjuvant (one served as EAE group), three groups were immunized with complete Freund’s adjuvant only, and a control group was injected with phosphate buffered saline only. Groups were sacrificed 3, 5, 7, or 12–13 days after the intervention and analyzed for early signs of CNS degeneration. RESULTS: Loss of mitochondrial membrane potential and oxidative changes was observed days before clinical disease debut at day 9.75 ± 0.89. The early mitochondrial changes were not associated with cytochrome C release, cleavage of caspases 9 (38/40 kDa) and 3 (17/19 kDa), and cleavage of PARP (89 kDa) or spectrin (120/150 kDa), and apoptosis was not initiated. Axonal degeneration was only present at disease onset. Increases in a range of cytokines and chemokines were observed systemically as a consequence of immunization with complete Freund’s adjuvant, whereas the encephalitogenic emulsion induced an upregulation of the chemokines Ccl2, Ccl20, and Cxcl1, specifically in brain tissue, 7 days after immunization. CONCLUSION: Five to seven days after immunization, subtle decreases in the mitochondrial membrane potential and an increased reactive oxygen species burden in brain tissue were observed. No cell death was detected at these time-points, but a specific expression pattern of chemokines indicates activity in the CNS, several days before clinical disease debut