Two different types of apnea induced by focal cold block of ventral medulla in rabbits.
The respiratory effects of unilateral focal cold block of ventral medulla were examined in rabbits. Focal cooling of the paraolivar region in the caudal area of ventral medulla induced prolongation of the expiratory time, with little change in the tidal inspiratory activity amplitude, leading to 'temporal apnea'. Whereas focal cooling of the region ventral to the retrofacial nucleus in the rostral part of the ventral medulla induced depression of tidal phrenic nerve activity amplitude, leading to 'suppression apnea'. Thus, two different types and regions of apnea were demonstrated in rabbits.
Homma
I
I
Department of Physiology, Showa University School of Medicine, Tokyo, Japan.
Isobe
A
A
Iwase
M
M
Kanamaru
A
A
Sibuya
M
M
D000818:Animals; D001049:Apnea / Q000145:classification / Q000503:physiopathology*; D003080:Cold Temperature; D008526:Medulla Oblongata / Q000503:physiopathology*; D010791:Phrenic Nerve / Q000503:physiopathology; D011817:Rabbits