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Hideto Kaba

Publications and source records attributed to Hideto Kaba.

6 recordsLinked to original sources
PubMed2004

Differences in development and cellular composition between neuronal cultures of rat accessory and main olfactory bulbs.

We previously established a primary culture system of the accessory olfactory bulb (AOB) to investigate the functional roles of individual types of neuron in pheromonal signal processing. However, the detailed characteristics of cultured AOB neurons were not yet apparent. In the present study, we address the cytological aspects of cultured AOB neurons using immunocytochemical staining methods. Cultured AOB neurons were compared with cultured main olfactory bulb (MOB) neurons in neuronal composition, maturational time course, and cell size. The number of total neurons, measured by microtubule-associated protein 2 (MAP2) immunostaining, progressively decreased, and glutamic acid decarboxylase positive (GAD+) interneurons were scarcely changed in their number in both AOB and MOB cultures over the culture periods. In contrast, the number of tyrosine hydroxylase positive (TH+) neurons in AOB cultures showed a slight, but significant, increase over time in culture, while those in MOB cultures remarkably decreased. The numbers of total neurons and GAD+ neurons were significantly greater in AOB cultures than in MOB cultures at all investigated time points. However, the numbers of TH+ neurons were lower at 7 days in vitro (DIV) and greater at 21 DIV in AOB cultures than in MOB cultures. The somatic sizes of all types of neurons at 14 DIV were significantly larger in AOB cultures than in MOB cultures. Furthermore, the frequency distributions of somatic sizes of total, GAD+, and TH+ neurons were significantly different between AOB and MOB cultures. These subtle differences in vitro may reflect in vivo differences between the AOB and MOB.

Animals↗
PubMed2004

Remodeling of reciprocal synapses associated with persistence of long-term memory.

We investigated a model of long-term memory in which the female mouse establishes pheromonal memory of its partner at mating. We examined the reciprocal synapses of the accessory olfactory bulb and found that pheromonal memory was associated with morphological changes in excitatory synapses in the early phase of memory acquisition and by changes in inhibitory synapses in the late phases of memory persistence. After extinction of pheromonal memory, these morphological changes were no longer present. These findings suggest that the persistence of pheromonal memory is associated with continuous and dynamic changes in the morphological plasticity of reciprocal synapses in the accessory olfactory bulb.

Animals↗
PubMed2003

Modulation of olfactory learning in young rats through intrabulbar GABA(B) receptors.

After training with an odour paired with foot shock on postnatal day 11, rat pups show an aversion to the odour in testing on postnatal day 12. The mechanisms underlying this aversive olfactory learning involve disinhibition of mitral/tufted cells in the olfactory bulb by the somatosensory stimulation-induced activation of centrifugal noradrenergic fibres originating in the locus coeruleus. The activity of mitral/tufted cells is regulated through gamma-aminobutyric acidA (GABA(A)) receptors in the external plexiform layer and GABA(B) receptors in the glomerular layer. We have previously presented that aversive olfactory learning in young rats is modulated through GABA(A) receptors in the olfactory bulb. In the present study we examined the consequence of manipulating GABA(B) receptors in the olfactory bulb during training. Baclofen, a GABA(B) receptor agonist when infused into the olfactory bulb during the pairing of an odour with foot shock, prevented aversive olfactory learning in a dose-dependent manner. Infusion of saclofen, a GABA(B) receptor antagonist, during training with a citral odour in the absence of foot shock produced aversive responses not only to the odour, but also to strange odours (benzaldehyde and vanillin) not previously presented. Such olfactory aversions were observed even if saclofen was infused without odour exposure. These results suggest that olfactory learning in young rats is modulated through GABA(B) receptors in the olfactory bulb.

Acyclic Monoterpenes↗
PubMed2003

Characteristics of prolidase from the erythrocytes of normal humans and patients with prolidase deficiency and their mother.

Prolidases I and II were highly purified from human erythrocytes. The effects of various amino acids, MnCl2 and mercaptoethanol, on these two enzymes were investigated. Normal prolidase II was very labile in the absence of MnCl2 or mercaptoethanol. The activity of prolidase II was maintained at about 76% by pre-incubation with MnCl2; it was then activated up to 140% by treatment with mercaptoethanol for 60 minutes at 37 degrees C. Normal prolidases I and II showed the highest activity against glycylproline or methionylproline in the presence of MnCl2. The activity of prolidase I against glycylproline was enhanced strongly by glycine and MnCl2, but not activated in the absence of MnCl2. The activity of prolidase II against methionylproline was enhanced three-fold in the presence of glycine and MnCl2, but its activity against glycylproline was very low even in the presence of MnCl2. A stronger enhancement of this activity was found in normal erythrocytes, and a lower level of this activity was found in erythrocytes of patients treated with glycine, MnCl2 and mercaptoethanol compared to those treated with glycine and MnCl2. The activity of prolidase II against methionylproline in all erythrocytes, of normal humans and of patients, was strongly activated by the addition of glycine with MnCl2 but suppressed by the addition of mercaptoethanol.

Chlorides↗