Integrated Flow Chamber System for Live Cell Microscopy.

quantification of the effect of mechanical loads on cells by live microscopy requires precise control of load and culture environment. Corresponding systems are often bulky, their setup and maintenance are time consuming, or the cell yield is low. Here, we show the design and initial testing of a new cell culture system that fits on standard light microscope stages.

Age-Dependent Neurogenesis and Neuron Numbers within the Olfactory Bulb and Hippocampus of Homing Pigeons.

Many birds are supreme long-distance navigators that develop their navigational ability in the first months after fledgling but update the memorized environmental information needed for navigation also later in life. We studied the extent of juvenile and adult neurogenesis that could provide such age-related plasticity in brain regions known to mediate different mechanisms of pigeon homing: the olfactory bulb (OB), and the triangular area of the hippocampal formation (HP tr). Newly generated neurons (visualized by doublecortin, DCX) and mature neurons were counted stereologically in 35 pigeon brains ranging from 1 to 168 months of age.

Altered orientation and flight paths of pigeons reared on gravity anomalies: a GPS tracking study.

The mechanisms of pigeon homing are still not understood, in particular how they determine their position at unfamiliar locations. The "gravity vector" theory holds that pigeons memorize the gravity vector at their home loft and deduct home direction and distance from the angular difference between memorized and actual gravity vector. However, the gravity vector is tilted by different densities in the earth crust leading to gravity anomalies.

Cognitive impairment in Gdi1-deficient mice is associated with altered synaptic vesicle pools and short-term synaptic plasticity, and can be corrected by appropriate learning training.

The GDI1 gene, responsible in human for X-linked non-specific mental retardation, encodes alphaGDI, a regulatory protein common to all GTPases of the Rab family. Its alteration, leading to membrane accumulation of different Rab GTPases, may affect multiple steps in neuronal intracellular traffic. Using electron microscopy and electrophysiology, we now report that lack of alphaGDI impairs several steps in synaptic vesicle (SV) biogenesis and recycling in the hippocampus.

Calsyntenin-1 docks vesicular cargo to kinesin-1.

We identified a direct interaction between the neuronal transmembrane protein calsyntenin-1 and the light chain of Kinesin-1 (KLC1). GST pulldowns demonstrated that two highly conserved segments in the cytoplasmic domain of calsyntenin-1 mediate binding to the tetratricopeptide repeats of KLC1. A complex containing calsyntenin-1 and the Kinesin-1 motor was isolated from developing mouse brain and immunoelectron microscopy located calsyntenin-1 in association with tubulovesicular organelles in axonal fiber tracts.

Proteomic analysis of synaptosomes using isotope-coded affinity tags and mass spectrometry.

Synaptosomes are isolated synapses produced by subcellular fractionation of brain tissue. They contain the complete presynaptic terminal, including mitochondria and synaptic vesicles, and portions of the postsynaptic side, including the postsynaptic membrane and the postsynaptic density (PSyD). A proteomic characterisation of synaptosomes isolated from mouse brain was performed employing the isotope-coded affinity tag (ICAT) method and tandem mass spectrometry (MS/MS).

The calsyntenins--a family of postsynaptic membrane proteins with distinct neuronal expression patterns.

We have identified two novel postsynaptic membrane proteins that are highly similar to calsyntenin-1 in their extracellular parts but vary considerably in their cytoplasmic segment. Calsyntenin-1 has recently been identified in our lab as a postsynaptic membrane protein with a highly acidic cytoplasmic segment with putative Ca(2+)-binding capacity (Vogt et al., 2001, Mol.

Truncating neurotrypsin mutation in autosomal recessive nonsyndromic mental retardation.

A 4-base pair deletion in the neuronal serine protease neurotrypsin gene was associated with autosomal recessive nonsyndromic mental retardation (MR). In situ hybridization experiments on human fetal brains showed that neurotrypsin was highly expressed in brain structures involved in learning and memory. Immuno-electron microscopy on adult human brain sections revealed that neurotrypsin is located in presynaptic nerve endings, particularly over the presynaptic membrane lining the synaptic cleft.

Calsyntenin-1, a proteolytically processed postsynaptic membrane protein with a cytoplasmic calcium-binding domain.

In a screen for proteins released from synapse-forming spinal cord neurons, we found the proteolytically cleaved N-terminal fragment of a transmembrane protein localized in the postsynaptic membrane of both excitatory and inhibitory synapses. We termed this protein calsyntenin-1, because it binds synaptic Ca2+ with its cytoplasmic domain. By binding Ca2+, calsyntenin-1 may modulate Ca2+-mediated postsynaptic signals.

Anatomy and physiology of a neural mechanism defining depth order and contrast polarity at illusory contours.

We studied the anatomy and physiology of neurons in monkey visual cortex, which contribute to mechanisms segregating figure and ground at contours based on information provided by occlusion cues. First, we defined the location of neurons sensitive to occluding (illusory) contours. These neurons were found most frequently in the pale cytochrome oxidase stripes of area V2 but rarely in V1.

Ryk-deficient mice exhibit craniofacial defects associated with perturbed Eph receptor crosstalk.

Secondary palate formation is a complex process that is frequently disturbed in mammals, resulting in the birth defect cleft palate. Gene targeting has identified components of cytokine/growth factor signalling systems such as Tgf-alpha/Egfr, Eph receptors B2 and B3 (Ephb2 and Ephb3, respectively), Tgf-beta2, Tgf-beta3 and activin-betaA (ref. 3) as regulators of secondary palate development.

Termination of the geniculocortical projection in the striate cortex of macaque monkey: a quantitative immunoelectron microscopic study.

The goal of this present study was to derive a new estimate of the synaptic contribution of the dorsal lateral geniculate nucleus (dLGN) to the subdivisions of its main recipient layer, layer 4C, of striate cortex of macaque monkey. The projection from the dLGN and its terminal boutons within layer 4C were visualized by immunodetection of the calcium binding protein, parvalbumin (PV), which is expressed in relay cells of the dLGN. The proportion of asymmetric synapses formed by PV-positive boutons within the alpha and beta sublayers of 4C was estimated by using a nonbiased stereological counting method.

Parcellation of the lateral premotor cortex of the macaque monkey based on staining with the neurofilament antibody SMI-32.

In macaque monkey, frontal and parasagittal brain sections were stained with SMI-32, an antibody directed against a nonphosphorylated neurofilament protein that labels pyramidal cells. The goal of this investigation was to find reliable criteria with which to draw the border between the motor (M1) and premotor (PM) cortex and delineate subdivisions within the lateral PM. Two-dimensional reconstruction of the staining patterns was also performed by flattening the series of frontal sections.

GABAB-receptor splice variants GB1a and GB1b in rat brain: developmental regulation, cellular distribution and extrasynaptic localization.

GABAB (gamma-aminobutyric acid)-receptors have been implicated in central nervous system (CNS) functions, e.g. cognition and pain perception, and dysfunctions including spasticity and absence epilepsy.

The junction-associated protein AF-6 interacts and clusters with specific Eph receptor tyrosine kinases at specialized sites of cell-cell contact in the brain.

The AF-6/afadin protein, which contains a single PDZ domain, forms a peripheral component of cell membranes at specialized sites of cell-cell junctions. To identify potential receptor-binding targets of AF-6 we screened the PDZ domain of AF-6 against a range of COOH-terminal peptides selected from receptors having potential PDZ domain-binding termini. The PDZ domain of AF-6 interacts with a subset of members of the Eph subfamily of RTKs via its COOH terminus both in vitro and in vivo.

Calretinin-immunoreactive local circuit neurons in area 17 of the cynomolgus monkey, Macaca fascicularis.

The connections of local circuit neurons immunoreactive for calcium-binding protein calretinin (CR-ir) were studied in area 17 of the macaque monkey visual cortex. Most CR-ir neurons were located in layers 2 and 3A. They were polymorphic and included bitufted, multipolar, pyramid-shaped neurons with smooth dendrites and Cajal-Retzius cells.

gamma-Aminobutyric acid-containing basal forebrain neurons innervate inhibitory interneurons in the neocortex.

The basal forebrain-neocortex pathway--involved in higher cognitive processing, selective attention, and arousal--is considered one of the functionally most important ascending subcortical projections. The mechanism by which this relatively sparse subcortical pathway can control neuronal activity patterns in the entire cortical mantle is still unknown. The present study in the cat provides evidence that gamma-aminobutyric acid-containing basal forebrain neurons participate in the neocortical projection and establish multiple synaptic connections with gamma-aminobutyric acid-releasing interneurons containing somatostatin or parvalbumin.