Differences in locomotor behavior revealed in mice deficient for the calcium-binding proteins parvalbumin, calbindin D-28k or both

We investigated the role of the two calcium-binding proteins parvalbumin (PV) and calbindin D-28k (CB) in the locomotor activity and motor coordination using null-mutant mice for PV (PV−/−), CB (CB−/−) or both proteins (PV−/−CB−/−). These proteins are expressed in distinct, mainly non-overlapping populations of neurons of the central and peripheral nervous system and PV additionally in fast-twitch muscles. In a test measuring repeated locomotor activity during 18–20 days, the analysis revealed a slightly increased activity in mice lacking either protein, while the lack of both decreased the number of beams crossed during active periods. An increase in the characteristic speed during the first 8 days could be attributed to PV-deficiency, while the elimination of CB in CB−/− and double-KO mice decreased the percentage of fast movements at all time points. In the latter, additionally a reduction of the fastest speed was observed. The alterations in locomotor activity (fast movements, fastest speed) strongly correlate with the impairment in locomotor coordination in mice deficient for CB evidenced in the runway assay and the rotarod assay. The graded locomotor phenotype (CB > PV) is qualitatively correlated with alterations in Purkinje cell firing reported previously in these mice. The presence or absence of either protein did not affect the spontaneous locomotor activity when animals were placed in a novel environment and tested only once for 30 min. In summary, the lack of these calcium-binding proteins yields characteristic, yet distinct phenotypes with respect to locomotor activity and coordination

“En los bordes del archivo: escrituras periféricas, escrituras efímeras en los Virreinatos de Indias”

En los bordes del archivo es el sitio web de "En los bordes del archivo: escrituras periféricas, escrituras efímeras en los Virreinatos de Indias”, proyecto coordinado entre dos equipos de investigación de la Universidad Complutense de Madrid (UCM) y del Consejo Superior de Investigaciones Científicas (CSIC).© En los bordes del archivo - 2017. Algunos derechos reservados. Licencia Creative Commons.. Consulta realizada en 2019-03-22.La finalidad que orienta el Proyecto Coordinado “En los bordes del archivo: escrituras periféricas, escrituras efímeras en los Virreinatos de Indias” queda definida en la voz que encabeza su título, estudiada en relación con la escritura hispanoamericana colonial y abordada desde una comprensión amplia del término, no sólo en su sentido más positivista, en tanto acumulación o repositorio de documentos para la conformación de la verdad historiográfica y la imposición del poder imperial, sino en las acepciones paralelas de “lugar de la memoria” y de “metáfora epistémica”, de herramienta que permite la interpretación “arqueológica” de los saberes.Peer reviewe

Oscillations, Timing, Plasticity, and Learning in the Cerebellum

The highly stereotyped, crystal-like architecture of the cerebellum has long served as a basis for hypotheses with regard to the function(s) that it subserves. Historically, most clinical observations and experimental work have focused on the involvement of the cerebellum in motor control, with particular emphasis on coordination and learning. Two main models have been suggested to account for cerebellar functioning. According to Llinás’s theory, the cerebellum acts as a control machine that uses the rhythmic activity of the inferior olive to synchronize Purkinje cell populations for fine-tuning of coordination. In contrast, the Ito–Marr–Albus theory views the cerebellum as a motor learning machine that heuristically refines synaptic weights of the Purkinje cell based on error signals coming from the inferior olive. Here, we review the role of timing of neuronal events, oscillatory behavior, and synaptic and non-synaptic influences in functional plasticity that can be recorded in awake animals in various physiological and pathological models in a perspective that also includes non-motor aspects of cerebellar function. We discuss organizational levels from genes through intracellular signaling, synaptic network to system and behavior, as well as processes from signal production and processing to memory, delegation, and actual learning. We suggest an integrative concept for control and learning based on articulated oscillation templates.SCOPUS: re.jinfo:eu-repo/semantics/publishe