A long-lasting change in the excitability of fetal brain neurons
following activation of dam's hypothalamus in rats.
Nakamura, S., S. Arakawa, and S. Nishiike.
Department of Physiology, Faculty of Medicine, Kanazawa University,
Kanazawa 920, Japan
APStracts 2:0066R, 1995.
The influence of the dam's brain on the electrical activity of brain
neurons was examined in the rat fetus, while still connected to the
dam by the umbilical cord. Under urethane-anesthesia, the spontaneous
or glutamate-induced discharge of single brainstem neurons in fetuses
was decreased by electrical stimulation of the dam's hypothalamus
(HYP). The changes occurred 21-122 sec after the start of the
stimulation, and persisted throughout the recording until the cells
were lost after 2.4-9.5 min. The effects of electrical stimulation of
dam's midbrain reticular formation (MRF) were much weaker and of
short duration compared with HYP stimulation. The dam's blood
pressure was increased immediately after the beginning of MRF or HYP
stimulation. The change was always greater with MRF than HYP
stimulation. Activation of the dam's MRF and HYP had no marked
influence on the blood flow in the fetal brain. These results
indicate the presence of a functional interaction between the brain
of the dam and that of its fetus mediated through the placenta.
Received 11 October 1994; accepted in final form 21 February
1995.
APS Manuscript Number R589-4.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 10 March 1995.