Neuroscience 2003 Abstract
| Presentation Number: | 610.7 |
|---|---|
| Abstract Title: | Acute estradiol application increases inward and decreases outward whole-cell currents of neurons in rat hypothalamic ventromedial nucleus (VMN). |
| Authors: |
Kow, L.*1
; Devidze, N.1
; Shibuya, I.
; Pfaff, D. W.1
1Lab. of Neurobiol. & Behav., The Rockefeller Univ., New York, NY |
| Primary Theme and Topics |
Autonomic, Neuroendocrine and Other Homeostatic Systems - Neuroendocrine -- Steroids and plasticity |
| Secondary Theme and Topics | Synaptic Transmission and Excitability<br />- Intrinsic Membrane Properties<br />-- Modulation and plasticity of intrinsic membrane properties |
| Session: |
610. Steroids & Plasticity III Poster |
| Presentation Time: | Tuesday, November 11, 2003 10:00 AM-11:00 AM |
| Location: | Morial Convention Center - Hall F-I, Board # I73 |
| Keywords: | ESTROGEN, HYPOTHALAMUS, PATCH CLAMP, POTENTIATION |
Our previous single-unit recording studies (SFN Abstr. ’02, #482.16) showed that acute estrogens can potentiate the excitation of VMN neurons. To investigate underlying mechanisms, whole-cell patch voltage clamp was used to study VMN neurons in 300-µm hypothalamic slices prepared from 20 female juvenile (3-5 wks) rats. Voltage steps or ramp were applied every 5 min to evoke whole-cell currents. After baseline recording, the neuron was treated with estradiol (E2, 10 nM) or vehicle through bath for up to 15 min and then washed. In 13 of the 22 E2-treated cells, the peak inward currents were within the range of the vehicle group (n=8). In the remaining 9 units, the average peak inward current started to increase within 5 min and reached 149, 172 and 160% at 5, 10 and 15 min of E2 treatment, respectively. These values are significantly greater than the pretreatment level and the levels of either vehicle and or non-responsive cells at each time point (all p < 0.01). Opposite results were observed for outward currents. Of the 16 E2-treated cells studied, 6 were responsive: their outward current was reduced significantly (all p < 0.02) and progressively from 100% at pretreatment to 82, 72 and 62% during E2 treatment period. Whenever observed, the effects of acute E2 were reversible after 5 to 10 min washing. The inward currents, peaking at around -40 mV clamp potential, appeared to be non-selective cation currents; and judging from the shape of their curves, the outward currents appeared to be delayed rectifier K currents. The acute E2 effects on these currents can explain our observed potentiation of the excitation of VMN neurons.
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
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