Journal of Neurophysiology, Vol 42, Issue 1 203-213, Copyright © 1979 by APS
Responses of single units in sixth lumbar dorsal root ganglion of female rats to mechanostimulation relevant for lordosis reflex
L. M. Kow and D. W. Pfaff
1. The activity of single units (n = 312) was recorded from dorsal root
ganglion L6 in female rats; 84% received input from cutaneous
mechanoreceptors. 2. Among cutaneous mechanoreceptive units (n = 263), 22%
responded to individual guard hair movement, 18% to down hair, 11% to
clitoral hair, and 14% to stimulation of tylotrich hair-haarscheibe (type
I) receptors, 5% responded to punctate skin deformation, but not hair
movement of pressure, and 18% responded to pressure. 3. No significant
differences between estrogen-treated and untreated ovariectomized rats were
observed in receptive-field size, or von Frey hair, or pressure threshold
of any given type of unit. 4. The lordosis reflex of female rats is
triggered by pressure, but not hair deflection, on skin regions innervated
by dorsal root L6 (10). Stimulation from the male rat mounting would cause
a barrage of action potentials from most of the unit types identified here,
but only pressure units and type I units gave sustained responses to a
lordosis-triggering type of pressure stimulation.
