PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Brain evolution”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources
PubMed1993

Heterochronical patterns of evolution in the transitional stages of vertebrate classes.

Transitional forms of the recent classes of vertebrates are only known in paleontology. The well described examples are: Eusthenopteron foordi (Crossopterygii), Ichthyostega and Acanthostega (Labyrinthodontia) between Osteichthyes and Amphibia, Seymouria baylorensis (Amphibiosaria) between Amphibia and Reptilia, Archaeopteryx lithographica (Archaeornithes) between Reptilia and Aves, and the mammal-like reptiles Pelycosauria, Therapsida and Cynodontia between Reptilia and Aves, and the description of their phylogenetical heterochronies in terms of peramorphosis and paedomorphosis shows the progressive role of the motorial, especially the locomotorial organ systems and their functions in comparison with the retarded evolution of the axial system, especially the skull and central nervous system. The evolution of the Hominidae shows the same rule. The evaluation of these transitional forms in their fossil context reveals them as inhabitants of biotopes situated in the border areas of coastal and shore landscapes of marine, brackish or fresh water. These biotopes have obviously favoured the innovations on the high taxonimic level of macro-evolutionary characteristics.

Animals↗
PubMed1990

Lactate compartmentation in hippocampal slices: evidence for a transporter.

Lactic acid accumulation has been implicated in the evolution of brain damage after ischemia. Since compartmentation of lactate may play a role in acid-base balance, lactate release from gerbil hippocampal slices was examined during a number of metabolic stresses including elevated [K+]e, ischemia, anoxia, and aglycemia. Slices were preincubated for 1 hr in artificial cerebrospinal fluid (ACSF) equilibrated with 95% O2/5% CO2 (pH 7.4 at 37 degrees C) and then transferred to tubes containing 300 microliters of test medium. The rate of lactate release in control slices was 9.64 nmol/min/mg protein and increased 2.6- and 3.2-fold in the presence of 60 mM potassium and anoxia, whereas the rate of lactate release was decreased by 50 and 25% during ischemia and aglycemia. Lactate release was temperature dependent and was only minimally influenced by removing Ca2+ or by adding 5 mM d-lactate to the ACSF. In contrast, pyruvate inhibited lactate release with an apparent Ki of 2.4 mM. The results suggest that lactate can be released from cells via a saturable and stereospecific lactate transporter with an apparent Km of 10.7 mM and Vmax of 43.7 nmol/mg protein/min. Such a relatively high-capacity transporter system can rapidly equilibrate brain lactate but is probably not involved in regulating intracellular acid-base balance.

Adenosine Triphosphate↗
PubMedDate not supplied

Neuromediators and neuromodulators. Evolution of compounds and evolution of hypotheses.

The probable features of the evolution of neuromediators (NM) and neuromodulators (NR) of different types are discussed. The assumption concerning the high rate of evolution of peptide NM and NR and the greater potentialities of the formation of new NM and NR of this type is substantiated. Monomolecular NM and NR are presumably more conservative, but have an advantage as regards the strict individualism of the systems of synthesis and degradation. Peptides, individual amino acids, and ATP are probably among the oldest NM and NR.

Adenosine Triphosphate↗
PubMed1988

The Glasgow-Liège Scale. Prognostic value and evolution of motor response and brain stem reflexes after severe head injury.

In 1982, we developed a new coma scale, the Glasgow-Liège Scale (GLS), which combines the Glasgow coma scale (GCS) with the quantified analysis of five brain stem reflexes. After severe head injury, the two most important parameters for determining the degree of encephalic disturbances are motor responses (M) and brain stem reflexes (R). The object of this study was to further evaluate the prognosis ability of M and R on admission and during the first month after injury. The study is based on 141 patients. The highest score, during the first day, was less than or equal to 7 on the GCS and 12 on the GLS. Using a multiple group logistic discriminant analysis, we confirmed that, in the first 24 hours, the study of brain stem reflexes appears to be the one factor with the best prognostic ability. We also showed that the prognostic value of certain signs is optimal for a limited period. If, within the two variables M and R, recovery follows an identical pattern whatever the final outcome may be, the restructing speed differs for each outcome. M follows an exponential curve spread over a long period explaining its importance in the course of time. On the other hand, R follows a linear model with straight lines more or less parallel for each outcome. R evolves over a short period of time. These clinical findings give us the opportunity to discuss the physio-pathology of head injury.

Adolescent↗
PubMed1989

Reversible multifocal encephalopathy following tuberculous infection.

Tuberculous encephalic infection is commonly reported as confined to Asians or Africans or people living in poor hygienic conditions; very often it follows meningitis in patients with lung TB infection. We describe three western patients coming from good social environment and suffering from multifocal tuberculous encephalopathy. Two of them showed neither meningitis or lung TB when CNS involvement appeared. Complete recovery after therapy is described, together with the evolution of brain CT and, in 1 case, MRI features. The instrumental findings accompanying the complete recovery suggest that the lesions described in these cases are a localized form of encephalitis responsive to medical treatment, unlike tuberculomas, which often need surgical treatment. The occurrence of tuberculous encephalic infection in western, middle-class patients with or without meningitis emphasizes that tuberculous encephalopathy must be considered in the differential diagnosis of multifocal brain lesions.

Adult↗