The effect of nerve growth factor on the rat olfactory receptor neurons following axotomy

THE EFFECT OF NERVE GROWTH FACTOR NEURONS FOLLOWING AXOTOMY

425 H.Yasuno,

KFukazawa,

M.Sakagami

RECEPTOR

and K.Noguchi”,

‘) Department

Department of Otolaryngology, 6634501, Japan.

ON THE RAT OLFACTORY

of Anatomy

and Neuroscience,

Hyogo College of Medicine,

Hyogo,

In mammals olfactory receptor neurons have a distinguished capability for regeneration following axotomy. The purpose of this study was to examine the effect of exogenous nerve growth factor (NGF) on the axotomized olfactory receptor neurons. Unilateral olfactory nerves of the male Sprague-Dawley rats (6 weeks-old) were transected and NGF (2ng/day) or saline were administered into the nasal cavity for 5 days. After that the animals were killed under deep anesthesia, and their olfactory mucosae were dissected out to examine the histological change and olfactory marker protein (OMP) mRNA expression by in situ hybridization. The result showed that mature olfactory receptor neurons expressing OMP mRNA were found in the NGF-treated rats, while the olfactory mucosa in control rats contained very few mature olfactory receptor neurons. These results indicate that exogenous NGF may alleviate degenerative changes of olfactory receptor neurons following axotomy.

EXPRESSION OF OLFACTORY RECEPTORS, G-PROTEINS AND AxCAMS DURING THE DEVELOPMENT AND MATURATION OF OLFACTORY SENSORY NEURONS IN THE MOUSE.

426

H..SAITO1.2,3, M. MIMMACKZ,

P. C..EMSON2,

J. KISlMOTO’

and E.B.KEVERNEI

‘Sub-Dept. of Animal Behav., Dept. of Zoology, Univ. of Cambridge, U.K. 2Lab. of Molecular and Cognitive Neurosci., Dept. of Neurobiol., The Babraham Institute, U.K. ‘Lab.for Neural Architec., RIKEN Brain Sci. Institute, Wako, Japan. Following cloning of three different types of mouse olfactory receptor genes, in situ hybridization histochemistry (ISH) has been carried out to examine the onset and expression pattern of these olfactory receptor genes in the mouse olfactory systems. neurons, indicated and that neurons neuronal receptors olfactory

Four other marker genes, BIG2, NCAM and G-proteins (Golf and Gp) detecting the maturation of the olfactory The ISH results in the main olfactory epithelium (Mob) were also the subject to the ISH for comparison. that each individual olfactory receptor signal was expressed independently at an early stage in the development the time of onset of specific olfactory receptor expression was not related to the maturation of olfactory sensory nor to the functional appearance of odourant detection. Some olfactory receptor genes were also found in the nonelement outside the MOE at the same period (embryonic day 12-16). Together, the early expression of olfactory in the MOE and outside the MOE suggest that they may play a role in axonal growth and guidance of the neurons.

SUBTYPE-SPECIFIC

427 MASUMI Dept. of

GLUTAMATE

Anatomy

We have studied

animals.

DISTRIBUTION OLFACTORY

& Embryology,

the synaptic

Tokyo Metropolitan

plasticity

OF

IONOTROPIC

BULR.

what types

Fuchu, Tokyo

in the mice, rat, or hamster accessory

induces the structural

To study

Inst. for Neurosci,

changes of postsynaptic

of glutamate

receptor

localize

density

anti-NMDAR2A/B,

GluR5/6/7 monoclonal

antibody.

GIuR2/3 distributed

anti-GluRl,

NMDARZA/B,

in the glutaminergic

and mitral/tufted

cell in the glomerulus cell and granulecell

GluRl, and that

anti-GluR4,

GluRI, GluR 5/6/7 distributed

in the mitraI/tufted

results may be shown that NMDAR2A/B,

between mitral/tufted

anti-GluR2/3.

olfactory

183-8526 bulb (AOB). Pheromonal

of glutaminergic

was examined in the AOB of rat or mice using immunocytochemical

anti-NMDARl,

NMDARl,

IN THE ACCESSORY

ICHIKAWA

mating stimulation

receptors

IMMUNOCYTOCHEMICAL

RECEPTOR

technique.

synapse

synapse,

distribution

Seven types

anti-GluR6/7

and/or

in the AOB of these of glutamate

antibodies

polyclonal

antibodies,

in the glomerular and mitral/tufted

were used: and anticell layer.

cell and granule cell layer. GluR4 was not localized in the AOB. These GluR 5/6/7 were localized on the synapses

between

vomeronasal

NMDARI, GluR2/3 were localized on the dendrodendritic in the mitral/tufted cell layer. Supported by CREST of JST.

nerve

synapses