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Pacemaker currents contribute to respiratory rhythmogenesis differently in rodent hibernators and non‐hibernators
Author(s) -
Gajda Barbara Marie,
Milsom William K
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a557-d
Subject(s) - hibernation (computing) , juvenile , respiratory system , biology , hamster , anesthesia , medicine , physiology , endocrinology , anatomy , state (computer science) , algorithm , computer science , genetics
Neonates of all rodents share many traits that are lost as they mature to adulthood but are retained in species that hibernate, leading to the hypothesis of “hibernator as neonate.” One such trait is the ability of neonates (but not the adults of non‐hibernators) to withstand cold and to recover spontaneously from hypothermic respiratory arrest. We tested if this ontogenetic transition reflects a greater ability of neonates to recruit pacemaker currents for respiratory rhythmogenesis by examining the extent to which juvenile and sub‐adult non‐hibernators (rats) and sub‐adult hibernators (hamsters) are affected by the elimination of pacemaker currents. We applied riluzole (RIL) and flufenamic acid (FFA) to in situ arterially perfused preparations to eliminate persistent sodium (RIL) and non‐specific cation currents (FFA) which resulted in a decrease in the frequency of phrenic nerve activity in sub‐adult hamsters > juvenile rats > sub‐adult rats. Therefore, pacemaker currents play a greater role in rhythm generation in hamsters and neonates supporting the “hibernator as neonate” hypothesis. Supported by the NSERC of Canada.