Effects of hypocapnia on spontaneous burst activity in the piriform-amygdala complex of newborn rat brain preparations in vitro.
We examined effects of hypocapnia on burst activity in the piriform-amygdala complex and C(4) inspiratory activity in limbic-brainstem-spinal cord preparations from 0- to 1-day-old rats. Hypocapnia (2% CO(2)) increased the burst rate in the piriform-amygdala complex but decreased the C(4) inspiratory burst rate. Since hyperventilation induces hypocapnia, and enhanced amygdala activity may be involved in induction of a sense of anxiety, our findings might explain the neuronal mechanism of a vicious circle between hyperventilation and an increased sense of anxiety.
Fujii
T
T
Department of Physiology, Showa University School of Medicine, Shinagawa-ku, Tokyo 142, Japan. oni@med.showa-u.ac.jp
Onimaru
H
H
Suganuma
M
M
Homma
I
I
D000679:Amygdala / Q000503:physiopathology*; D000818:Animals; D000831:Animals, Newborn; D001007:Anxiety / Q000503:physiopathology / Q000523:psychology; D001933:Brain Stem / Q000503:physiopathology; D006985:Hyperventilation / Q000503:physiopathology / Q000523:psychology; D016857:Hypocapnia / Q000503:physiopathology* / Q000523:psychology; D001239:Inhalation; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000503:physiopathology