Abstract Background The Y-box binding protein 1 (YB-1) is considered to be one of the key regulators of transcription and translation. However, so far only limited knowledge exists regarding its cellular distribution in the adult brain. Results Analysis of YB-1 immunolabelling as well as double-labelling with the neuronal marker NeuN in rat brain tissue revealed a predominant neuronal expression in the dentate gyrus, the cornu ammonis pyramidal cell layer, layer III of the piriform cortex as well as throughout all layers of the parahippocampal cortex. In the hilus of the hippocampus single neurons expressed YB-1. The neuronal expression pattern was comparable in the hippocampus and parahippocampal cortex of adult macaques and humans. Double-labelling of YB-1 with the endothelial cell marker Glut-1, the multidrug transporter P-glycoprotein, and the astrocytic marker GFAP did not indicate a co-localization. Following status epilepticus in rats, no induction of YB-1 occurred in brain capillary endothelial cells and neurons. Conclusion In conclusion, our study demonstrates that YB-1 is predominantly expressed in neurons in the adult brain of rats, macaques and humans. Lack of a co-localization with Glut-1 and P-glycoprotein argues against a direct role of YB-1 in the regulation of blood-brain barrier P-glycoprotein.
A bstract : Palisade endings occur only in extraocular muscles, and their function is unknown. They form a cuff of nerve terminals around the tips of muscle fibers. We describe here the advantages of using antibodies to a synaptosomal‐associated protein (SNAP‐25) to study properties of palisade endings in man, monkey, and rat. The stain can be combined readily with other immunofluorescence procedures, and results suggest that the synapses of palisade endings do not bind α‐bungarotoxin (i.e., are not motor), nor do they contain substance P. These double‐labeling data support the hypothesis that palisade endings are non‐nociceptive sensory receptors, and could serve a proprioceptive function. With SNAP‐25 immunolabeling, palisade endings were identified in the rat for the first time. Thus, palisade endings appear to be present in all vertebrate extraocular muscles studied to date. Their apparent universality, which contrasts with the more variable manifestation of extraocular muscle spindles and Golgi tendon organs, would be expected if proprioceptive feedback is necessary to the function of the ocular motor system, and if palisade endings are the critical proprioceptive structure.
The distribution of herpes simplex virus type 1 (HSV-1) in human geniculate, vestibular ganglia, and vestibular nuclei was determined in 10 human temporal bones and brainstems of five individuals by PCR. HSV-1 was found in 3 of 10 of each ganglia and vestibular nuclei. The various patterns of HSV-1 infection of vestibular structures are compatible with virus migration from the vestibular ganglia to the vestibular nuclei and from the ipsilateral to the contralateral vestibular nucleus via commissural fibers.
Descending projections from the superior colliculus (SC) motor map to the saccadic omnipause neurons (OPNs) were examined in monkeys by using anterograde transport of tritiated leucine. The SC was divided into three zones: the rostral pole of the motor map, a small horizontal saccade zone in central SC, and a large horizontal saccade zone in caudal SC. Tracer injections into the intermediate layers of the three zones led to different patterns of silver grain deposits in and around nucleus raphe interpositus (RIP), which contains the OPNs: 1) From the rostral pole of the motor map, coarse axon branches of the crossed predorsal bundle spread medially into the RIP, branched, and terminated predominantly unilaterally over cells on the same side. 2) From the small horizontal saccade zone, the axon branches were of a finer caliber and terminated diffusely in the RIP, mainly on the same side. 3) From the large horizontal saccade zone, no terminal labeling was found within the RIP. 4) From the rostral pole of the motor map and small horizontal saccade zone, fiber branches from the ipsilateral descending pathway terminated diffusely over RIP. 5) In addition, terminal labeling in reticulospinal areas of the pons and medulla increased in parallel with the size of the saccade according to the SC motor map. The results suggest that there are multiple projections directly onto OPNs from the rostral SC but not from the caudal SC associated with large gaze shifts. The efferents from the rostral pole of the motor map may subserve the suppression of saccades during visual fixation, and those from the small horizontal saccade zone could inhibit anatagonist premotor circuits.
