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1236 EFFECTS OF PRENATAL STRESS ON THE DEVELOPMENT OF CORTICOTROPIN RELEASING FACTOR (CRF) NEURONS OF HYPOTHALAMIC PARAVENTRICULAR NUCLEUS (PVN) IN

THE FETAL RAT BRAIN. TAKASH~ FUJIOKAI, IKUYO AK~MURA. YOSHIYUKI SAKATA. YAT.&~ WATANABE. TAMOTSU SHIBASAKV AND SHOJI NAKAMURA. Deot. of Phvsiol. and ‘Deot. of Obstet. and Gvnecol.. Yamaauchi Univ. Sch. of Med., Ube, Yamami 755. and Qeot. of Inte. Med.. Nionon Med. Sch.. Tokvo 113. JAPAN

We investigated the effect of prenatal stress on the development of CRF neurons of the PVN in the fetal rat

brain by immunohistochemistory. Pregnant rats were restricted in a small cage for 30 min daily from

gestational day 15 to 17. On embryonic day 18, the animals were sacrificed for investigating changes in the

morphology of CRF neurons in the PVN of the fetal brain. The number of the cell processes of CRF neurons

increased in the stress group as compared to control. In addition, the size of the varicosities of CRF fibers in

the median eminence was smaller in the stress group than control, while the density of the varicosities became

higher after the stress. These results suggest that maternal stress during pregnancy may facilitate the

development of CRF neurons of the PVN in the fetal rat.

1237 NERVE GROWTH FACTOR INDUCES BRADYKININ RESPONSE IN CAPSAISIN SENSITIVE NEURONES CULTURED FROM ADULT RAT DORSAL ROOT GANGLIA. MASANORI KASAI, KAZUE

MIZUMURA, TAKAO KUMAZAWA, Dept. of Neural Regul., Res. Inst. of Environ. Med., Nagoya Univ.,Nagoya 464-O I, Japan

Effects of bradykmm (BK) and capsaicm (CAP) were tested to small stze (30 ,U mr) dorsal root ganglion neurones (DRG) freshly dissociated (dtssoctated group), cultured in the presence of nerve growth factor (NGF group) and cultured in the absence of NGF (no-NGF groups). Application of BK (lo-7 to 10-5 M) induced a depolarization in about a half of neurones (46 of 84,55%) in NGF group. However, BK (lo-5 M) did not change the membrane potential in most of neurones m dissociated groups (17 of 23,74%) and in non-NGF group (18 of 20,90%/o). In NGF group, a percentage of the responded neurones to BK and the amplitude of the depolarization reached to the peak at 2 days cultivation. In contrast, applications of capsaicm (CAP) induced a depolarization m most of neurones (30 of 32,94%) in dissociated group, 13 of 28 (46%) in no-NGF group and 52 of 69 (75)% in NGF group. In NGF group, the percentage of the responded neurones to CAP and the amplitude of the depolarization were not changed until 2 days cultivation. All of BK sensitive neurons until 2 days cultivation were sensitive to CAP. The results demonstrated that NGF can influence an expression of BK-response in CAP-sensitive DRG neurones. Effects of prostaglandin E2 and the enhancement by a low concentration of PGE2 to BK-response have also been observed in neurones cultured with NGF.

1238 Characterization of cholinergic nerve properties of SN49, a neuronal cell line derived from mouse septum

TAKESHI SUZUKI, KOICHIRO KAWASHIMA, Department of Pharmacology, Kyoritsu College of

Pharmacy, Tokyo 105, Japan

SN49 is derived from the fusion of N18TG2 murine neuroblastoma cell, which lacks cholinergic markers, with the

septal neuron of postnatal day 21 mouse (Lee et al., Dev. Brain Res., 2, 219-228, 1990). Homogeneous and

immortalized cell line which shows cholinergic properties would be very useful for the study on cholinergic function.

Since little information on SN49 cell is available, we studied the development of cholinergic nerve properties, especially

choline acetyltransferase (ChAT) activity, in this cell line. When SN49 cells were cultured in DEEM containing 10%

fetal bovine serum, cell number was increased without change in ChAT activity. Retinoic acid or dibutyryl CAMP

treatment increased ChAT activity and elongated neurites for 2 days in culture. In the presence of retinoic acid,

intracellular acetylcholine content was also increased. These results suggest that SN49 has cholinergic properties derived

from parental septal cell.