Article Figures & Data
Figures
- Fig. 1.
Stimulation protocol. B is a diagram of the rat's body traced directly from one half of a rat's pelt. Areas stimulated during the experiment are demarcated and numbered. Some of these are shown on the picture of the rat inA. C and D are diagrams of the female rat's reproductive tract. C shows the positions of the stimulating balloons implanted in the uterine horns and temporarily placed in the vaginal canal. D shows the position of the stimulating balloon temporarily inserted in the colon and the lubricated cotton swab applicator temporarily positioned next to the cervix.
- Fig. 2.
Recording site and data analysis.A, Diagram of a transverse section through the rat brainstem at the level of obex indicating the single recording site (dot at bottom of recording symbol), which was 200 μm lateral to the midline and 200 μm ventral from the surface. X, Nucleus of the solitary tract. B, RMS calculation from the raw multi-unit signal. The top line is a raw multi-unit recording from one rat during skin stimulation of regions 12–14 (see Fig. 1A,B). Thebottom line illustrates and labels the components of the analysis program (see Materials and Methods). The Max AVG generated during each stimulus is demarcated by a vertical slash mark.
- Fig. 3.
Multi-unit responses to skin stimulation.A, The Max AVG values of multi-unit responses in each stage of estrous (D, P, E, and M) to stimulation of each of the 20 demarcated skin regions of the hindquarters (see Materials and Methods; Figs. 1B, 2A). *p ≤ 0.05, **p ≤ 0.01. Data are shown as mean ± SEM. B, Shaded areas correspond to those regions whose stimulation produced a significantly greater magnitude of response in P, and the dashed areas correspond to those regions whose stimulation failed to produce estrous changes in response magnitude.
- Fig. 4.
Examples of single-unit responses from five different experiments. The unit in A was from a rat in proestrus and responded by inhibition to cervix pressure (CVX). The unit in B was from a rat in estrus and responded by excitation to cervical pressure. The unit in C was from a rat in diestrus and responded to uterine distention (UT) by inhibition. The unit in D was from a rat in proestrus and responded to vaginal distention (VAG) by inhibition. The unit inE was from a rat in metestrus and responded to colon distention (COL) by excitation. The top lines are frequency histograms for each unit. The middle lines are the discriminated representation of the single unit, and the bottom lines indicate the stimulus. Thearrows indicate latency to response, which was 11 sec for A, 1 sec for B, 13 sec forC, 6 sec for D, and 2 sec forE.
- Fig. 5.
Single-unit responses to visceral stimulation. Percent inhibitory and excitatory responses to stimulation of cervix (A), vaginal canal (B), uterine horn (C), and colon (D) in each stage of estrous (D, P, E, and M). * and #p ≤ 0.05, significantly different from P.
Tables
Estrous stage # of units responsive to any visceral stimulus Cervix pressure Vaginal distention Uterine distention Colon distention D 15 9 (60%) 6 (40%) 12 (80%) 6 (40%) P 17 14 (82%) 5 (30%) 11 (65%) 6 (35%) E 11 7 (64%) 7 (64%) 4 (36%)* 4 (36%) M 13 7 (54%) 6 (46%) 9 (70%) 4 (31%) Total n(%) 56 37 (66%) 24 (43%) 36 (64%) 20 (36%) ↵* P < 0.05, significantly less than D.
Estrous stage Cervix pressure Vaginal distention Uterine distention Colon distention D 16.7 ± 3.1 13.1 ± 4.1* 13.1 ± 2.5 9.0 ± 3.7 P 14.0 ± 3.2 3.2 ± 1.7 7.8 ± 2.6 6.1 ± 1.8 E 3.5 ± 2.3* 3.7 ± 1.6 16.5 ± 6.0 12.2 ± 6.6 M 3.4 ± 1.9* 7.1 ± 3.7 9.8 ± 3.1 3.2 ± 1.4 ↵* p ≤ 0.05, significantly different from P. Data are represented as mean ± SEM.
- Table 3.
Summary of estrous changes in responses of NG neurons to hindquarter skin and pelvic visceral stimulation
Cervix pressure Vaginal distention Uterus distention Colon distention Brush of perineum, hip, tail Brush of foot, leg, abdomen Magnitude of response — — — — greatest in P ∅ Response shifts from inhibition to excitation P → E ∅ D → P ∅ — — Latency shifts from long to short P → E D → P ∅ ∅ — — —, Not tested; ∅, no change.
