Table 2.

Cluster analysis of shuttle box escape responses (mean escape latency in sec ± SEM).

Rats which received open-field, sucrose-consumption, and passive-avoidance tests:
	Helpless (N = 10)	Non-helpless (N = 11)	Total sample (N = 21)
FR1	11.89 ± 0.62*	3.53 ± 0.46	7.51 ±1.00
FR2	28.13 ± 0.82*	8.54 ±1.30	17.87 ± 2.32

Control rats which did not receive behavioral-screening tests:
	Helpless (N = 12)	Non-helpless (N = 9)	Total sample (N = 21)
FR1	12.99 ± 0.39*	5.83 ± 1.07	9.92 ± 0.93
FR2	28.23 ± 0.67*	11.17 ± 1.54	20.92 ± 2.03

^*p < 0.01, helpless vs. non-helpless