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Purpose: Pontine and cerebellar developments were investigated in low-birthweight (LBW) infants at term-equivalent age (TEA) using magnetic resonance imaging (MRI).Methods and Materials: The study subjects were a consecutive series of LBW infants born with a birthweight of <1,500 g. Among them, 51 neonates with an extremely low birthweight (ELBW) and 65 neonates with a very low birthweight (VLBW) infants underwent MRI exam at TEA. We measured the pontine anteroposterior diameter (APD), cerebellar vermian APD and height, and cerebellar transverse width using midline sagittal and axial T1 weighted images. Twenty term neonates with neonatal asphyxia showing a normal pattern and white matter injury on MRI exam served as a control group. Gender differences in these parameters were compared among the LBW groups.Result: Pontine APD in the ELBW group was significantly less than that in the control group. Cerebellar vermian APD and height were similar among the 3 groups. However, cerebellar transverse width was significantly less in the LBW groups than in the control group. A significant gender-related difference in pontine APD was evident, but cerebellar measurements showed no significant gender difference.Conclusion: LBW infants showed significantly developmental delay in terms of pontine APD and cerebellar width. A sex difference in pontine growth was evident among LBW infants.

To clarify the changes that occur in γ-aminobutyric acid type A (GABAA) receptor-mediated effects and contribute to alterations in the network activities after neuronal injury, we studied intracellular Ca2+concentration ([Ca2+]i) dynamics in a rat facial-nerve-transection model. In facial motoneurons, an elevation of the resting [Ca2+]i, GABA-mediated [Ca2+]itransients, enhancement of the glutamate-evoked [Ca2+]iincreases, and spontaneous [Ca2+]ioscillations were induced by axotomy. All these axotomy-induced modifications were abolished by the GABAA-receptor antagonist bicuculline andN-methyl-d-aspartate (NMDA)-receptor antagonistd(−)-2-amino-5-phosphonopentanoic acid. A downregulation of K+-Cl−cotransporter (KCC2) mRNA, an increase in intracellular Cl−concentration ([Cl−]i), and transformation of GABAergic hyperpolarization to depolarization were also induced by axotomy. We suggest that in axotomized neurons KCC2 downregulation impairs Cl−homeostasis and makes GABA act depolarizing, resulting in endogenous GABA inducing [Ca2+]ioscillations via facilitation of NMDA-receptor activation. Such GABAA-receptor-mediated [Ca2+]ioscillations may play a role in neural survival and regeneration.

Background: Diffuse lamellar keratitis (DLK) is marked by the presence of diffuse or multifocal infiltrates confined to the laser in situ keratomileusis (LASIK) interface. These infiltrates are culture-negative, and the etiology is thought to be noninfectious. Most cases of DLK occur within the first week or 2 following surgery. Cases: We described 2 cases of DLK that occurred 3 months after LASIK. These patients were treated with intensive topical corticosteroids. Results: Treatment with topical corticosteroid was instituted, with rapid improvement in patient symptoms, visual acuity, and slit-lamp biomicroscopic findings. Conclusion: DLK may occur as late as 3 months after LASIK.

AbstractObjectives: Although in Japan the T&T olfactometer is most commonly used in patients suffering from smelling disorders, no scientific analysis has been performed so far. The objective of this study was to clarify whether the five odorants used in the T&T olfactometer are suitable or not. We mapped the glomeruli activated by the five test odorants employed in the T&T olfactometer. The expression of c-fos protein as a marker of neuronal excitation was monitored using an immunohistochemical technique. Study Design:The expression of c-fos protein in the rat olfactory bulb was investigated to determine what part of the olfactory system is activated by five odorants used in the T&T olfactometer. Methods:Each rat was isolated in a clean cage for 120 min to reduce the basal expression of c-fos protein. Each rat was fixed in the cage and exposed to one of five test odorants for 90 min. The expression of c-fos protein was measured using an immunohistochemical technique. Results:Each odorant activated numerous glomeruli and the patterns of distribution of activated glomeruli were specific to each odorant. Glomeruli in most regions of the bulb were activated by all five test odorants. Conclusion:We assume that in the T&T olfactometer the optimal ((five)) odorants are employed, because the glomeruli activated by those odorants showed unique patterns in the immunohistochemical assay.Copyright © 2002 S. Karger AG, Basel

Gene expression of major urinary protein (MUP) mRNAs was examined in the mouse nasal tissue. By polymerase chain reaction, we identified two cDNA segments encoding MUP 4 and MUP 5 genes in the nose. The expression level of both MUP 4 and 5 mRNAs in the nasal tissue was very high and exceeded that of the liver. Liver MUPs are excreted into the urine and are known to play an important role in pheromonal communication. We showed that nose and liver MUPs were composed of different subtypes of MUPs and that nose MUP mRNAs was detected in prepubescent periods when liver MUP mRNAs had not yet been transcripted. In situ hybridization revealed that nose MUP mRNAs are localized in the lateral wall and nasal septum and their expression pattern is identical to that of rat odorant-binding protein (OBP)-I. We also identified cDNA of mouse OBP-II gene from the nasal tissue and showed that the expression pattern of MUP gene was identical to that of OBP-II gene in the nose. These histological data indicate that nose MUPs are favorable for catching odorant molecules rather than pheromones, and may share their function with OBPs. © 1999 John Wiley & Sons, Inc. J Neurobiol 39: 227–236, 1999

In situ hybridization was employed to study the expression ofbcl-2 mRNA and its family members,bax andbcl-x mRNAs, in the developing inner ear. We found that in the cochlear structure, sensory epithelial cells, the spiral ganglion and stria vascularis expressed these mRNAs in postnatal period in a temporally similar manner, but in embryos, neitherbax norbcl-x mRNA were expressed in the sensory epithelium from embryonic day (E) 13 to 19. In contrast to these patterns,bcl-2 mRNA was expressed by E15 to E19, and the expression at E13 was below the lower limit of detection. Non-neuronal tissue (stria vascularis) also expressed these three transcripts during development. These results suggest thatbcl-2 family members may be differentially involved in the differentiation of sensory epithelial cells, spiral ganglia, and stria vascularis. In particular, the differential expression patterns in the cochleovestibular neurons suggest that proliferating and differentiating neurons utilize distinct members of thebcl-2 family.

Many calcitonin gene-related peptide-like immunoreactive (CGRP-IR) fibers were found in the vestibular end-organs and the cochlea of rats. CGRP-IR fibers in the vestibular end-organs originated in the bilateral cell groups dorsolateral to the genu of the facial nerve. These fibers formed a fiber plexus at the base of the sensory epithelia in the maculae of the otolith organs and the ampullae of the semicircular canals, and formed synaptic contacts with the nerve chalice on type I vestibular sensory cells. CGRP-IR fibers in the cochlea originated in the ipsilateral lateral superior olivary nucleus. Most of them existed in the inner spiral bundle under the inner hair cells, and formed synaptic contacts with afferent terminals on the inner hair cells. These findings suggest a postsynaptic modulation of CGRP on the vestibular and cochlear information at the level of type I vestibular sensory cells and the inner hair cells.

Background: Diffuse lamellar keratitis (DLK) is marked by the presence of diffuse or multifocal infiltrates confined to the laser in situ keratomileusis (LASIK) interface. These infiltrates are culture-negative, and the etiology is thought to be noninfectious. Most cases of DLK occur within the first week or two following surgery. Case: We describe two cases of diffuse lamellar keratitis that occurred 3 months after LASIK. These patients were treated with intensive topical corticosteroids. Results: We treated both patients with topical corticosteroids, with rapid improvement in patient symptoms, visual acuity, and slit-lamp biomicroscopy findings. Conclusion: DLK may occur three months after LASIK. Nippon Ganka Gakkai Zasshi