Table 2.

Comparison of facilitation of EPSPs and IPSPs from the ipsilateral PT by stimuli applied in the ipsilateral NR, evoked via ipsilaterally and contralaterally descending pathways

1	2	3	4	5	6	7
Pathways	Test	Motoneurones tested (Total number)	Motoneurones facilitated (%)	Facilitation mean ±s.e.m. (mV)	Facilitation cond/test (%)	Facilitated PSP latency (ms)
Ipsilaterally descending	EPSPs	37	59%	0.26 ± 0.04	158 ± 11% (6)	5.4 ± 0.1*
Ipsi NR & ipsi PT	IPSPs	37	27%	0.37 ± 0.08	189 ± 7% (3)	6.2 ± 0.3
Contralaterally descending	EPSPs	23	39%	0.22 ± 0.03	373% & 116%	6.0 ± 0.4
Ipsi NR & ipsi PT	IPSPs	23	13%	0.35 ± 0.06	—	8.7 ± 2.3

1, pathways via which facilitation was evoked; 2, tested PSPs; 3, total numbers of motoneurones tested; 4, percentages of motoneurones in which PSPs were facilitated; 5, mean amplitude of the facilitated components of the PSPs in mV; data for all motoneurones tested. 6, relative increases in test PSPs in percentage of control levels (calculated for motoneurones in which PSPs were evoked by the test stimuli alone with the numbers of motoneurones in parantheses). 7, latencies of the facilitated components measured from the last PT stimulus. No statistically significant differences were found between the degree of facilitation evoked via ipsilaterally or contralaterally descending pathways (amplitudes of the facilitated components in column 5 or their latencies in column 7 but differences in proportions of motoneurones in which it was found were not statistically significant.