Figure 1.
Diagrammatic representation of the experimental design. A, The characterization of kinetic neural commands and of eyelid kinematics requires a precise measurement of exhaustive correlation indicators. The kinetic variables were determined here from the firing properties of antidromically identified orbicularis oculi (OO) motoneurons located in the facial nucleus (VII n) and interpositus neurons located in the cerebellar posterior interpositus nucleus (IP n). In turn, the kinematic variables were collected from eyelid position, velocity, and acceleration data. A complete list of kinetic and kinematic parameters measured in this study is included in Tables 1 and 2. The two types of variable were associated by means of dynamic correlation analysis. The diagram also illustrates the stimulating (Stim.) and recording (Rec.) sites, as well as the eyelid coil and EMG electrodes implanted in the upper eyelid. III n, Oculomotor complex; V n, trigeminal nucleus; VI, abducens nucleus; AccVI n, accessory abducens nucleus; GG, Gasser ganglion; R n, red nucleus. B, For classical conditioning of eyelid responses, we used a delay paradigm consisting of a tone (370 ms, 600 Hz, 90 dB) as a CS. The CS started 270 ms before and coterminated with an air puff (100 ms, 3 kg/cm2) used as an US.