An Inact Cerebellar Fastigial Nucleus (CFN) is an Important Determinant of CO2 Sensitivity in Awake Goats

• Published in: The FASEB journal 2006-03, Vol.20 (4), p.A786-A786
• Main Authors: Martino, Paul Frank, Davis, S, Opansky, C, Pan, L G, Krause, K, Qian, B, Bonis, J M, Forster, H V
• Format: Article
• Language: English
• ISSN: 0892-6638; 1530-6860
• DOI: 10.1096/fasebj.20.4.A786-b

We previously reported that in goats with chronically implanted stainless steel microtubules, microdialysis induced focal acidosis in the rostral CFN (rCFN) and caudal CFN (cCFN) increased and decreased pulmonary ventilation (VI), respectively. Here we report that injection of 10ul (n=8) ibotenic acid into the rCFN significantly (P < 0.05) increased both VI (36.1% ± 0.11) and breathing frequency (f) (42% ± 0.3) up to one hour after injection, with no significant effects on tidal volume (VT), mean arterial blood pressure (MABP) or heart rate (HR). 10ul (n=5) ibotenic acid injections into the cCFN did not significantly change VI, f, VT, MABP, or HR up to one hour after injection. However, in all goats, there were balance and posture deficits between 3 to 24 hours after injection. Histology indicated that in all goats portions of both the rCFN and cCFN were lesioned. These lesions did not significantly alter resting PaCO2, but decreased (P < 0.02) whole body CO2 sensitivity by 17%. In contrast, in two goats where the lesions were outside the CFN there was an average increase in the CO2 sensitivity of 52.5% ± 4.5. These data indicate that an intact CFN is an important determinant of CO2 sensitivity and that the rCFN and cCFN have both common and unique contributions to physiological functions. Supported by NIH HL‐25739 and by the Department of Veterans Affairs.