Plasticity in D1-Like Receptor Expression Is Associated with Different Components of Cognitive Processes

Dopamine D1-like receptors consist of D1 (D1A) and D5 (D1B) receptors and play a key role in working memory. However, their possibly differential contribution to working memory is unclear. We combined a working memory training protocol with a stepwise increase of cognitive subcomponents and real-time RT-PCR analysis of dopamine receptor expression in pigeons to identify molecular changes that accompany training of isolated cognitive subfunctions. In birds, the D1-like receptor family is extended and consists of the D1A, D1B, and D1D receptors. Our data show that D1B receptor plasticity follows a training that includes active mental maintenance of information, whereas D1A and D1D receptor plasticity in addition accompanies learning of stimulus-response associations. Plasticity of D1-like receptors plays no role for processes like response selection and stimulus discrimination. None of the tasks altered D2 receptor expression. Our study shows that different cognitive components of working memory training have distinguishable effects on D1-like receptor expression

No evidence that footedness in pheasants influences cognitive performance in tasks assessing colour discrimination and spatial ability

The differential specialization of each side of the brain facilitates the parallel processing of information and has been documented in a wide range of animals. Animals that are more lateralized as indicated by consistent preferential limb use are commonly reported to exhibit superior cognitive ability as well as other behavioural advantages.We assayed the lateralization of 135 young pheasants (Phasianus colchicus), indicated by their footedness in a spontaneous stepping task, and related this measure to individual performance in either 3 assays of visual or spatial learning and memory. We found no evidence that pronounced footedness enhances cognitive ability in any of the tasks. We also found no evidence that an intermediate footedness relates to better cognitive performance. This lack of relationship is surprising because previous work revealed that pheasants have a slight population bias towards right footedness, and when released into the wild, individuals with higher degrees of footedness were more likely to die. One explanation for why extreme lateralization is constrained was that it led to poorer cognitive performance, or that optimal cognitive performance was associated with some intermediate level of lateralization. This stabilizing selection could explain the pattern of moderate lateralization that is seen in most non-human species that have been studied. However, we found no evidence in this study to support this explanation

Abstract concept learning in a simple neural network inspired by the insect brain

The capacity to learn abstract concepts such as 'sameness' and 'difference' is considered a higher-order cognitive function, typically thought to be dependent on top-down neocortical processing. It is therefore surprising that honey bees apparantly have this capacity. Here we report a model of the structures of the honey bee brain that can learn sameness and difference, as well as a range of complex and simple associative learning tasks. Our model is constrained by the known connections and properties of the mushroom body, including the protocerebral tract, and provides a good fit to the learning rates and performances of real bees in all tasks, including learning sameness and difference. The model proposes a novel mechanism for learning the abstract concepts of 'sameness' and 'difference' that is compatible with the insect brain, and is not dependent on top-down or executive control processing

Report and preliminary results of METEOR-cruise M 29/1: Buenos-Aires -Montevideo, 17.6.-13.7.94

During METEOR cruise M 29/1 the shipboard acoustical systems HYDROSWEEP and PARASOUND were used on a 24 hour schedule to record continuous high resolution bathymetric and sediment echosounding profiles. The digitization and storage of the echosounding seismograms were realized by usage of the software package PARADIGMA (Spiess, 1992). The underway geophysical program along several profiles on the Argentine continental margin serves the long term research program Sonderforschungsbereich 261, the complete coverage of the South Atlantic Ocean with a net of sampling stations and geophysical profiles. Along the profiles the recorded data provided valuable information for finding suitable coring stations from different sedimental environments on the continental margin, which can be well discriminated by their different echotypes. (orig.)Available from TIB Hannover: RO 7630(58) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDeutsche Forschungsgemeinschaft (DFG), Bonn (Germany)DEGerman

Report and preliminary results of METEOR Cruise M 41/1, Malaga - Libreville, 13.2. - 15.3.1998 With partial results of METEOR Cruise 41.2, Libreville - Vitoria, 18.03.1998-15.04.1998

Available from TIB Hannover: RO 7630(114) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Bericht und erste Ergebnisse der Meteor-Fahrt M 16/2 Recife-Belem, 28.4. - 21.5. 1991

With 97 Figs., 11 tabs.SIGLEAvailable from TIB Hannover: RO7630(19) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman