Normal delay eyeblink conditioning in mice devoid of astrocytic S100B.

S100B is a small calcium binding protein synthesized and secreted mostly by astrocytes. Mice devoid of S100B (S100B-KO) develop without detectable anatomic abnormalities of the brain, but exhibit enhanced hippocampal long-term potentiation and enhanced performance in hippocampus-dependent learning and memory tasks, indicating that S100B has a crucial role in hippocampal neuronal plasticity. In the present study, we examined whether S100B has a similar role in the cerebellar regions, because Bergmann glia, a specialized subset of astrocytes in the cerebellar cortex, express a particularly large amount of S100B under physiologic conditions.

Neural-activity-dependent release of S100B from astrocytes enhances kainate-induced gamma oscillations in vivo.

S100B is the principal calcium-binding protein of astrocytes and known to be secreted to extracellular space. Although secreted S100B has been reported to promote neurite extension and cell survival via its receptor [receptor for advanced glycation end products (RAGE)], effects of extracellular S100B on neural activity have been mostly unexplored. Here, we demonstrate that secreted S100B enhances kainate-induced gamma oscillations.

Impact of S100B on local field potential patterns in anesthetized and kainic acid-induced seizure conditions in vivo.

S100B is a calcium-binding protein predominantly expressed in astrocytes. Previous studies using gene-manipulated animals have suggested that the protein has a role in synaptic plasticity and learning. In order to assess the physiological roles of the protein in active neural circuitry, we recorded spontaneous neural activities from various layers of the neocortex and hippocampus in urethane-anesthetized S100B knockout (KO) and wildtype (WT) control mice.

Stimulus-induced behavior in F1 hybrids of seizure-sensitive and seizure-resistant gerbils.

We previously established two strains of Mongolian gerbil: a seizure-sensitive strain, established by selective inbreeding for motor seizures elicited by a stimulus called the S method and a seizure-resistant strain that does not exhibit inducible seizures. The behavior of the seizure-sensitive strain is characterized by a progressive increase in responsiveness to weekly application of the S method, from repetitive backward ear movements appearing after postnatal day 40, to a full-blown seizure, while the seizure-resistant strain is apparently unaffected by the stimulation. The difference between these two strains is presumably genetic.

Gerbils of a seizure-sensitive strain have a mitochondrial inner membrane protein with different isoelectric points from those of a seizure-resistant strain.

The distribution of proteins in the cerebral cortex of a seizure-sensitive (SS) strain of gerbil and its seizure-resistant (SR) counterpart was profiled using two-dimensional gel electrophoresis. A series of proteins of similar molecular weight (around 83 kDa) showed small but consistent differences in their isoelectric point (pI) with indistinguishable profiles of distribution between the two strains. Amino acid sequences of peptides produced by limited proteolysis of each protein in the spots from the strains were identical or highly homologous to those of mitofilin, a mitochondrial inner membrane protein (IMMT) in humans.

Manipulation of the somatosensory cortex modulates stimulus-induced repetitive ear movements in a seizure-sensitive strain of gerbil.

Some Mongolian gerbils (Meriones unguiculatus) respond to stimulation by seizures, the pattern of which changes progressively during development. We previously established a seizure-sensitive strain, MGS/Idr, in which all animals exhibit such stimulus-induced seizures. We have now noted that all adults of this strain also show repetitive backward movements of the ears at the ears at the beginning of stimulus-induced seizures, although the incidence varies with the individual.

Cortical somatosensory evoked potentials of seizure-sensitive and seizure-resistant gerbils.

The Mongolian gerbil is known as an animal model that often exhibits spontaneous seizures that are characteristic of human epilepsy. Whereas there is much more information available relating this phenomenon to anatomical and electrophysiological characteristics of the hippocampal formation, the somatosensory cortex has rarely been the focus of attention. Given the existence of the fine grain cortical barrels developed in an orderly matrix, the vibrissa ascending system was thought the best sensory channel in which the gerbil neocortical excitability was to be tested.

Two types of aggregate in the cerebral cortex of a seizure-sensitive strain of the Mongolian gerbil.

A 70-kDa protein, P70, found mostly in the pyramidal cells of the cerebral cortex of cobalt-induced epileptogenic rats, has been implicated in epileptogenesis. The presence of a P70-like substance was searched for immunohistochemically in the cerebral cortex of MGS/ldr, a seizure-sensitive strain of the Mongolian gerbil (Meriones unguiculatus) that we previously established. Immunoreactive aggregates were observed in the pyramidal neurons of the motor cortex and the primary somatosensory cortex.

Site of cortical utricular representation with special reference to the somatosensory barrel field in the gerbil.

In mammals, the osseous semicircular canals of the vestibular labyrinths are usually embedded in the pyramis of the temporal bone. Thus, the osseous semicircular canals are a cavity system that can only be visualized by injection molding. Exceptionally, the walls of the osseous semicircular canals of the Mongolian gerbil are not embedded, but exposed in the hollow space in the temporal bone.

Sequencing of cDNA encoding serum albumin and its extrahepatic synthesis in the Mongolian gerbil, Meriones unguiculatus.

We have sequenced serum albumin cDNA from liver of the Mongolian gerbil, Meriones unguiculatus. The deduced amino acid sequence showed 82.6% and 73.

Age-related appearance of dystrophic axon terminals in cerebellar and vestibular nuclei of Mongolian gerbils.

In the brains of 360-day-old Mongolian gerbils, numerous swellings immunoreactive to anti-neurofilament antibody were observed in cerebellar and vestibular nuclei. The number of these swellings was the same in two gerbil strains with different susceptibility to spontaneous motor seizures by various stimuli, but much more numerous in gerbils as compared with the 360-day-old Slc:Wistar rats. Such swellings were only occasionally found before 60 days of age in gerbils, but they increased in number about fivefold from 60 to 180 days of age and about quadruple from 180 to 360 days of age.

Altered axon terminals containing concentric lamellar bodies of cerebellar Purkinje cells in Mongolian gerbil.

Altered axon terminals containing concentric lamellar bodies were observed in cerebellar and vestibular nuclei of the Mongolian gerbil. The terminals increased in number from 30 days of age onward, and reached about tenfold at 360 days. The numbers were the same in two gerbil strains with different susceptibility to spontaneous motor seizures by various stimuli, but about threefold those in Slc:Wistar rat.

The surface evoked potential and parvalbumin-immunoreactivity in the somatosensory cortex of the developing rat.

The development of the rat somatosensory system was followed electrophysiologically and immunohistochemically. In the surface evoked potential elicited in the primary somatosensory cortex by electrical stimulation of the whisker C3 follicle, a short-latency positive wave was first recorded on postnatal Day 2. A long-latency positive wave was recorded in some pups on postnatal Day 7 and in most pups on postnatal Day 8.

Intrinsic and drug-induced seizures of adult and developing gerbils.

Seizures elicited by posture change and intraperitoneal administration of convulsants were studied ontogenetically in the Mongolian gerbil (Meriones unguiculatus). In posture change, the first signs of seizure appeared after age 6 weeks with maximal frequency at 8-9 weeks. Adults developed complex, but stereotyped, seizures.

Calmodulin and calbindin localization in retina from six vertebrate species.

Calmodulin is abundant in the central nervous system, including the retina. However, the localization of calmodulin in the retina has not been described in detail. We therefore decided to investigate calmodulin localization in retinae from six vertebrate species, by using immunohistochemical labeling with four different rabbit polyclonal antibodies against calmodulin.

Parvalbumin immunoreactivity in the central auditory system of the gerbil: a developmental study.

Changes in parvalbumin-like immunoreactivity were studied during ontogenetic development of the central auditory system of the Mongolian gerbil (Meriones unguiculatus). The nucleus of the trapezoid body contained cells that could be stained on the day of birth while in the superior olivary complex, prominent staining of cell somata was only found at P15 (postnatal day 15). Neurons located in the ventral nucleus, in the dorsal nucleus of the lateral lemniscus and in the inferior colliculus developed parvalbumin immunoreactivity mostly between P11-P15 (ventral nucleus), P15-P19 (dorsal nucleus) and P15-P19 (inferior colliculus), respectively.

Calbindin D28K as a marker for the degeneration of the striatonigral pathway in Huntington's disease.

An antibody raised against the chick calcium-binding protein calbindin D28K was used in immunohistochemical studies of normal post mortem human brain and the brains of individuals with Huntington's disease. Calbindin D28K immunoreactivity in the caudate nucleus and putamen coincided with the distribution of areas of acetylcholinesterase staining termed the matrix. In the matrix, calbindin D28K immunoreactivity was present in medium-sized neurons, the major neuronal population, however a further minor population of more strongly stained large neurons was detected.

Coexistence of parvalbumin and glycine in the rat brainstem.

The coexistence of glycine- and PV-immunoreactivities was studied immunocytochemically in the nuclei of the superior olive, trapezoid body, cochlea and lateral lemniscus. All of the PV-immunoreactive neurons in the nuclei of the superior olive and trapezoid body were immunoreactive to glycine but not to GABA. In the dorsal cochlear nucleus, PV-positive neurons were sometimes immunoreactive to glycine.

Appearance of parvalbumin-specific immunoreactivity in the cerebral cortex and hippocampus of the developing rat and gerbil brain.

Developmental changes in the distribution of parvalbumin-specific immunoreactivity in the brain, in particular in the cerebral cortex and hippocampus, were followed immunohistochemically in two different species, the rat and the Mongolian gerbil (Meriones unguiculatus) using an antibody raised against for rat parvalbumin. The gerbil is known to develop its auditory and visual capacity later than rat. In both the rat and gerbil, parvalbumin-specific immunoreactivity appeared after birth in both the cerebral cortex and hippocampus.

Localization of parvalbumin mRNA in rat brain by in situ hybridization histochemistry.

Parvalbumin mRNA was localized in rat brain by in situ hybridization using a 35S labelled rat parvalbumin cDNA and a synthetic oligodeoxyribonucleotide (corresponding to base sequences 140 to 183 of rat parvalbumin cDNA). Strongest hybridization signals were detected in the Purkinje cells of the cerebellum and in neurones of the reticular nucleus of the thalamus. Signal was also detected in the cerebral cortex, hippocampus, basal ganglia and brain stem in agreement with the distribution of parvalbumin immunoreactivity.

[Calmodulin and neuron: immunohistochemical studies].

Calmodulin is present in higher concentrations in brain tissues. The content rapidly increased during the 2nd postnatal week in rat brain. Although the protein is ubiquitous in all eukaryotic cells, immunohistochemical studies have revealed that calmodulin is mainly localized in the neurons, exhibiting a similar distribution to that of gamma-type neuron-specific enolase.

Loss of matrix calcium-binding protein-containing neurons in Huntington's disease.

In post-mortem brain specimens from patients dying with a clinical diagnosis of Huntington's disease (HD) immunohistochemistry showed a substantial loss from the neostriatum of neurons containing the calcium-binding protein calbindin 28K. These calbindin neurons, and the straital compartment in which they are sited, are particularly damaged in HD, suggesting that a failure of calcium buffering or homeostasis may contribute to cell death in HD.

Lateral motion of fluorescent molecules embedded into cell membranes of clonal myogenic cells, L6, changes upon cell maturation.

The lateral motion of fluorescent molecules embedded into cell membranes of myogenic cell line, L6, was measured. The motion of S-F-ConA became faster at cell fusion stage, and became slower after fusion. On the other hand, the motion of lipid analog, F18, was not changed at cell fusion stage.

The effect of axotomy and denervation on calmodulin content in the superior cervical sympathetic ganglion of the rat.

Calmodulin (CaM) in the superior cervical sympathetic ganglion (SCG) of the rat and its changes after transection of the pre- or postganglionic nerves were studied biochemically and immunohistochemically. The concentration of CaM in the SCG was assayed using the extent of activation of CaM-dependent adenylate cyclase from bovine neural retina. In the SCG, CaM concentration was 4.