Table 1.

Summary of results from our lab demonstrating the opposing actions of estrogens on learning and memory across a variety of tasks. Studies were conducted in ovariectomized, young adult virgin Sprague-Dawley female rats and treatments administered 48 and 24 h before behavioral training unless otherwise specified.

Behavioral task	Direction of learning modulation	Treatment or cycle stage	Dose, timing, other notes
Place task	↑	EB; systemic injection	10 μg to young adult a,b,c and elderly ratsc, 4.5 μg/kg to young adultd and middle-agede LE rats; enhancement blocked by intrahippocampal ICI 182,780b
	↑	ES; intracranial infusion	0.5 μM infusion into dorsal hippocampus; infusion into dorsolateral striatum had no effect on place learningf
	↑	ES; intracranial infusion	A single 0.5 μM infusion into dorsal hippocampus enhanced place learning when given 2 h, but not 15 min, before trainingg
	↑	Genistein; oral pellets	Multiple daily oral dosings to LE rats beginning 48 h before trainingd
	↑	PPT; systemic injection	333 μg/kg to LE rats; higher (1000 μg/kg) and lower (33, 100 μg/kg) doses not effectiveh
	↑	DPN; systemic injection	100, 333, and 1000 μg/kg to LE ratsh
	↑	Br-Erb-041; systemic injection	100 μg/kg to LE rats; higher (333 μg/kg) and lower (10, 33 μg/kg) doses not effectiveh
	↑	G1; systemic injection	10 μg/kg to LE rats; only effective when given 30 min before training after 48 and 24 h of G1 primingi
Metric change in object location	↑	Proestrus	LE rats in proestrus showed better recognition of a change in metric pattern than rats in estrusj
	↑	EB; systemic injection	45 μg/kg to LE ratsj
Rewarded spontaenous alternation	↑	Proestrus, diestrus	Rats in proestrus and diestrus showed increased spatial alternation behavior compared to rats in estrusk
Response task	↓	EB; systemic injection	10 μg to SD ratsa,l, 4.5 μg/kg and 45 μg/kg to LE ratsd; impairment blocked by intrastriatal ICI 182,780l
	↓	ES; intracranial infusion	0.5 μM infusion into dorsolateral striatum; infusion into dorsal hippocampus had no effect on response learningf
	↓	ES; intracranial infusion	A single 0.5 μM infusion into dorsolateral striatum imapired response learning when given 2 h, but not 15 min, before trainingm
	↓	Genistein; oral pellets	Multiple daily oral dosings to LE rats beginning 48 h before trainingd
	↓	PPT; systemic injection	333 and 1000 μg/kg to LE ratsh
	↓	DPN; systemic injection	333 and 1000 μg/kg to LE ratsh
	↓	Br-Erb-041; systemic injection	100 μg/kg to LE rats; higher (333 μg/kg) and lower (10, 33 μg/kg) doses not effectiveh
	↓	G1; systemic injection	100 μg/kg to LE rats 48 and 24 h before training; no acute dose requiredi
Double object recognition	↓	EB; systemic injection	45 μg/kg to LE ratsj
Operant delayed spatial alternation	↓	17-β estradiol; silastic capsule	Chronic estradiol replacement impaired DSA performance in young adultn,o, middle-agedo,p, and elderlyo LE rats
	↓	Genistein; oral pellets	Chronic daily oral dosings impaired DSA performance in middle-aged LE ratsq
	↓	DPN; systemic injection	Chronic daily injections of 20 μg/kg; higher (80, 200 μg/kg) doses not effectivep
	↓	PPT; systemic injection	Chronic daily injections of 200 μg/kg subtly impaired DSA performance late in testing under long delaysp
Dual solution strategy	Place	Proestrus; EB, systemic injection	Proestrous rats showed preference for place over response strategies with no change in learning speedk,r
	Response	Estrus; Oil; systemic injection	Estrous rats showed preference for response strategies with no change in learning speedk,r

Abbreviations: EB: 17β-estradiol benzoate; ES: 17β-estradiol 3-sulfate; SD: Sprague-Dawley; LE: Long-Evans; OVX: ovariectomized; DSA: delayed spatial alternation.

^aKorol and Kolo, 2002;

^bZurkovsky et al., 2006;

^cKorol et al., 2007. Experiments were conducted using Fischer 344 x Brown Norway rats.

^dPisani et al., 2012b;

^eNeese et al., 2014;

^fZurkovsky et al., 2007; ES was infused directly into the dorsal hippocampus or dorsolateral striatum 48, 24, and 2 h before behavioral testing.

^gKorol et al., 2010;

^hPisani et al., 2012a;

ⁱPisani et al., 2013;

^jTunur et al., 2012;

^kKorol et al., 2004;

^lKent et al., 2005;

^mZurkovsky et al., 2011;

ⁿWang et al., 2008;

^oWang et al., 2009;

^pNeese et al., 2010a;

^qNeese et al., 2012;

^rMcElroy and Korol, 2005.