Search PubMed⌕ Search

Biomedical subjects

N Onoda

Publications and source records attributed to N Onoda.

At least 127 records · Page 7Linked to original sources
PubMed1988

Monoclonal antibody immunohistochemistry of rabbit olfactory receptor neurons during development.

Staining patterns for monoclonal antibodies produced against the rabbit olfactory bulb were studied from embryonic day 14 up to 30 days after birth in the rabbit olfactory receptor neurons. One monoclonal antibody, 112D5, stained all of the receptor neurons in the olfactory epithelium and vomeronasal organ during development. The other, 114G12, showed a unique gradual expression in the olfactory receptor neurons. 114G12-Positive cells first appeared in the epithelium of the embryonic day-17 fetus. At embryonic day 25 or 26, 114G12-positive cells were situated in the superficial receptor cell layer. The arrangement in the positive and negative receptor neurons was 'superficial-positive' and 'deep-negative'. Thereafter, a gradual increase in the number of 'superficial-positive' cells was accompanied by a decrease in the 'deep-negative' cells. These changes continued until postnatal day 30. The negativity of staining for monoclonal antibody 114G12 in the deep compartment was retained in the adult rabbit. The supporting cells and basal cells were monoclonal antibody 114G12-negative throughout development. This unique developmental pattern suggests that monoclonal antibody 114G12 is a useful probe for studies on neurogenesis in adult animal. In contrast to the olfactory epithelium, the vomeronasal organ was monoclonal antibody 114G12-negative throughout development. Thus monoclonal antibody 114G12 makes a molecular distinction between the olfactory receptor neurons and vomeronasal system.

Aging↗
PubMed1988

Monoclonal antibody immunohistochemistry of degenerative and renewal patterns in rabbit olfactory receptor neurons following unilateral olfactory bulbectomy.

Degeneration and regeneration of olfactory receptor neurons were studied in adult rabbits by immunohistochemical procedures following unilateral olfactory bulbectomy. Staining patterns of the olfactory receptors of the lesioned side were compared with those of the intact side in the nasal septum at various postoperative periods (12h-6 months) following lesion. Monoclonal antibodies, produced against the rabbit olfactory bulb, were used as histochemical markers. A slight decrease in the number of olfactory receptor neurons occurred at 24 h after lesion. One monoclonal antibody 112D5 stained all receptor neurons including degenerating neurons, but the other 114G12 showed a rapid decrease in immunostaining so that 114G12-positive cells disappeared within 7 days after lesion. 114G12-positive cells reappeared at 4 weeks following lesion. By 3 months, 114G12-positive cells were arranged in a plane at the apical region of the superficial compartment of the receptor cell layer, suggesting a recapitulation of development pattern of the receptor neurons. Thereafter, the number of 114G12-positive cells increased progressively and the staining pattern of the olfactory epithelium was like that of control animals by 6 months. Monoclonal antibody 114G12 is thus the first marker that is not specific to olfactory neurons and can be used to characterize certain embryonic traits during the degeneration and regeneration of the olfactory epithelium in the adult mammal.

Animals↗
PubMed1988

Phorbol ester pretreatment attenuates the growth hormone (GH) response to GH-releasing factor in cultured rat pituitary cells.

The effect of phorbol ester pretreatment on rat (r) GH release induced by GH-releasing factor (GRF) or 8-bromo-cyclic (c)AMP was investigated using rat pituitary cells cultured in monolayers. Pretreatment with 12-O-tetradecanoylphorbol-13-acetate (TPA) for 3 h significantly suppressed the rGH release induced by GRF, but not that by 8-bromo-cAMP 20 h later; this suppressive effect of TPA was concentration-dependent from 8 to 160 nmol/l, and complete suppression was observed after pretreatment with 80-160 nmol TPA/l. Production of cAMP by pituitary cells stimulated with GRF was similarly attenuated in TPA-pretreated cells. The rGH responsiveness to GRF of these cells was fully recovered on prolonged culture (40 h), suggesting that the inhibitory effect of TPA is reversible. In contrast, pretreatment with GRF (5 nmol/l) resulted in suppression of the rGH response to subsequent exposure to GRF (5 nmol/l) or 8-bromo-cAMP (10 mmol/l), but not to TPA. These observations suggest that pretreatment with TPA modifies the rGH response to GRF at steps before the formation of cAMP.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1987

A monoclonal antibody specific for a subpopulation of retinal bipolar cells in the frog and other vertebrates.

One monoclonal antibody 115A10 (MAb 5A10) specifically stained a subpopulation of retinal bipolar cells in various vertebrates. In the bullfrog retina, MAb 5A10 stained the large bipolar cells, but not the small bipolar cells. Labeling of the living bipolar cells was observed in isolated cell preparation of the frog retina. MAb 5A10 can serve as a cell-specific marker of the bipolar cells.

Animals↗
PubMed1987

Olfactory input to the lateral hypothalamus of the old world monkey.

Responses of lateral hypothalamic neurons to 8 odors were studied in chronic unanesthetized old world monkeys (Macaca irus). Many neurons (54.5%) responded to a single odor only, and the number of neurons responding to 2, 3 and 4 odors decreased successively. No neuron responded to as many as 5 odors. Thus, the presence of olfactory input and a highly discriminative ability for odors were found in the lateral hypothalamic area (LHA). Neuronal responses to the same odors were also studied in the septum (Spt). In anesthetized old world monkeys, evoked potentials were recorded in the LHA and in areas of the Spt and the nucleus accumbens (Acc) during stimulation of the olfactory bulb (OB). When the Spt (and probably the Acc with it) was subsequently destroyed, OB-evoked potentials in the LHA disappeared. Next, by injecting horseradish peroxidase (HRP) into the LHA, an olfactory pathway to the LHA was examined. Labeled neurons were found mainly in the Spt and the Acc, and only partly in other areas. However, labeled neurons were scarcely found in the prepyriform (PPF)-entorhinal (ER) area or in the olfactory tubercle (OT). The present study thus shows that an olfactory pathway to the LHA passes through the Spt and probably also the Acc, but not through the PPF-ER areas nor through the OT in the old world monkey.

Animals↗
PubMed1984

Response selectivity of neocortical neurons to specific odors in the rabbit.

Odor responses of neocortical neurons in rabbits under light pentobarbital anesthesia were studied in a restricted area in the lateral half of the prefrontal cortex close to the frontal pole. A preevent cumulative sum chart provided a visual display of the change in unit discharge rate following each odor stimulation, and critical levels on each chart provided a visual display of statistical significance. The neocortical neurons studied were activated predominantly by biologically significant odors, such as feces, urine, and dry food. Of those same neurons, 90% failed to respond to pure-chemical odors, and no neurons were found that responded to pure-chemical odors alone. Some neurons responded exclusively to one of the animal-product odors. Some odor-sensitive neurons were affected by electrical stimulation of the mediodorsal thalamic nucleus. Responses to the animal-product odors were observed after ablation of the trigeminal and/or vomeronasal inputs. The responses to these pheromone-like substances are discussed in the context of a central role for odor-sensitive neocortical neurons in cognitive aspects of discrimination of specific odor patterns in the mammals.

Animals↗
PubMed1984

Odor response characteristics of thalamic mediodorsal nucleus neurons in the rabbit.

Extracellular responses were recorded from neurons in the thalamic mediodorsal nucleus (MD) of the lightly anesthetized rabbit. Eighty-seven neurons responded to electrical stimulation of the lateral olfactory tract (LOT shocks). They were located in the medial portion of the MD. In the same portion, negative field potentials with a short latency were evoked by the electrical stimulation of the olfactory projection area in the neocortex (OPA shocks). Fifty-nine MD neurons responded both to LOT and to OPA shocks. Among them, 17 thalamocortical relay neurons (which responded antidromically to OPA shocks) were found to respond transsynaptically to LOT shocks. Of the 87 LOT-responsive MD neurons, 48 responded to the odors applied. Eight odor-sensitive neurons were found to be the thalamocortical relay neurons. Thus, it was proven for the first time that a portion of the olfactory input to the OPA is mediated via relay neurons in the MD. Characteristics of response of MD neurons to odor stimulation were compared with those of OPA neurons. MD neurons did not show a selectivity of response to odors of urine, feces, or dry food pellets, to which OPA neurons responded exclusively. These results were discussed in relation to the functional role of the MD-OPA projection system in the discrimination of specific odors.

Animals↗
PubMed1984

Changes in cytochrome oxidase activity of the rabbit olfactory cortex following unilateral olfactory bulbectomy.

The effects of unilateral olfactory bulbectomy on cytochrome oxidase (CO) activity in the olfactory cortex were studied in adult rabbits. In intact rabbits, layer Ia of the olfactory cortex stained symmetrically for CO activity as a continuous brown band. In animals with unilateral lesion of the olfactory bulb (OB), a great decrease in the level of CO activity was found in layer Ia ipsilaterally. The change became prominent about 12 hr after OB lesion. Thereafter no further decrease in CO activity was observed up to 6 months. A decrease in the level of CO activity was observed in only the denervated lamina to which the OB neurons project directly, but not along the synaptic chain in the olfactory cortex.

Animals↗
PubMed1983

Response characteristics of lateral hypothalamic neurons to odors in unanesthetized rabbits.

Extracellular responses of 103 neurons to eight odors were studied in the lateral hypothalamic area (LHA) of unanesthetized rabbits. In response to electrical stimulation of the olfactory bulb (OB), 97 units were excited with latencies of 3.7-68.0 ms (mean, 19.4 ms) and the activity of 6 units was suppressed. In the LHA, 90 units of 103 were found that responded to from one to eight odors. The number of units that responded to three odors was the most numerous (22%) among these odor-sensitive units. Lateral hypothalamic (LH) neurons showed high response probabilities to cineole (0.72), cyclotene (0.68), and isovaleric acid (0.54). Of the recorded units, 94% showed an excitatory-type response to both electrical stimulation of the OB and odor stimuli of the olfactory mucosa, while only 6% showed an inhibitory-type response to both stimuli. These results suggest that the olfactory effect on the LHA is predominantly excitatory. Responses to a concentration series of odors were examined in 24 LH neurons. In most cases, response intensity did not increase monotonically with increasing odor concentration. Instead, the concentration-response curves of most units showed a peak or inflections during the concentration series. Compared with results obtained from other olfactory structures in different species, it appears that LH neurons do not contribute much to odor discrimination in rabbits.

Animals↗
PubMed1978

Dependence of the activity of interpositus and red nucleus neurons on sensory input data generated by movement.

Cats performed flexion movements of the forearm, and the discharge of interpositus and red nucleus neurons was examined for relationships to the motion and to the EMG activity of agonist and antagonist muscles. It is shown that, over a wide range in the time course of the motion, the activity of the neurons is covariant with both the EMG and the movement parameters, in particular, the velocity. Also, the discharge of the interpositus neurons is modulated in phase with the velocity of passive movement. It is concluded that during fast, intentional movements, sensory input data generated by motion is a major determinant of the output of the interpositus nucleus. Furthermore, the results are consistent with the concept that this output provides a continuous modulation of spinal segmental mechanisms by way of the red nucleus and rubrospinal tract.

Animals↗
PubMed1978

Relationships between sensory input, motor output and unit activity in interpositus and red nuclei during intentional movement.

The relationship between unit activity in interpositus (8 units) and red nuclei (11 units) and the EMG activity of the biceps during intentional elbow flexion movements was investigated by means of cross-correlation analysis. This analysis showed that there were long-lasting (200 msec) changes in the probability of EMG activity both before and after a single spike in neurons which covaried with the motor output. The dependence of the activity of these units on sensory inputs was investigated by (1) calculating the quantitative relationship between angular displacement and unit activity and (2) recording unit activity after the sensory input from peripheral afferents had been eliminated by dorsal rhizotomy.

Action Potentials↗