Fig. 3.

Endogenous cholinergic activity increases MN output during fictive locomotion. (A) Local methoctramine application (100 μM and 1 mM, 10-sec duration) decreased locomotor output as seen in rectified/integrated L2 ventral root recordings. (B) Schematic demonstrating positioning of the drug injection pipette through a slit made in the pia matter above the motor column. (C) Average reduction by methoctramine (100 μM and 1 mM) of locomotor-related burst amplitude reported relative to control (n = 4). (D) Local methoctramine application (1 mM, 5-sec duration) during fictive locomotion did not affect contralateral activity. (E and F) Average amplitude and frequency of locomotor-related bursts recorded before and during methoctramine application (1 mM, 1- to 5-sec duration, n = 8). (G) Rectified/integrated (Upper) and raw (Lower) traces of locomotor output recorded from the L2 root during the local application of physostigmine (1 mM, 5-sec duration). ∗, significantly different to 100 μM methoctramine. #, significantly different to control.