Single and repeated punctate stimulation evokes flexion activity that is gestational age dependent.

<p>A, Cutaneous sensory threshold to punctate stimulation significantly increases with gestational age; B, threshold force required to evoke leg withdrawal and example flexion reflex EMG traces from term and preterm infants are shown. C, Threshold flexion reflex EMG responses in preterm infants are significantly greater than in term (two-way ANOVA, ***p<0.0001 age group, **p = <0.0001 time; Fisher's unpaired t-test, 250 ms, *p = 0.02; 500 ms, ***p<0.0001, 750 ms, ***p<0.0001). Note- two EMG recordings excluded from the analysis due to technical artefact. D, Brief, low frequency repeated punctate stimulation sensitised infant flexion reflex EMG activity as shown by a significantly larger flexion response to a threshold hair after 10 seconds of repeated stimulation, compared to the responses to the same threshold hair when tested 10 s before the train (two-way ANOVA, *p = 0.04 treatment,***p = 0.002, time; Fisher's paired t-test, 250 ms, *p = 0,002, n = 11, pooled term and preterm.