Premium
The relationship of afterhyperpolarizations of extraocular motoneurons to membrane potential
Author(s) -
Barmack N. H.
Publication year - 1976
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490020512
Subject(s) - membrane potential , extraocular muscles , compensation (psychology) , neuroscience , evoked potential , chemistry , anatomy , biology , psychology , psychoanalysis
The effect of membrane potential displacements caused by external current injection on the amplitudes of two antidromically evoked afterhyperpolarizations (AHP 1 and AHP 2 ) was measured in extraocular motoneurons. AHP 1 had a reversal potential of –70m V and an average compensation for displacements from the reversal potential (“compensation gain”) of –0.36. AHP 2 had a reversal potential of –80mV and a compensation gain of –0.08. Measurements of input resistance of these motoneurons demonstrate a 30–50% decrease at depolarized membrane potentials. This rectification could account for the apparent lack of summation of AHP 2 . The functional role of AHP 1 and AHP 2 in the regulation of discharge frequencies of extraocular motoneurons during normal eye movements is discussed.