Table 2.

Summary of animal research focusing on neurotransmitter systems.

No.	Strain	Sex	Age	Physical Activity	Stress Model	Main Outcome	Reference
1	C57BL/6J	male	7–8 weeks	voluntary wheel running	chronic social defeat stress	increased TH expression and number of TH-positive neurons in the VTA	[23]
2	C57BL/6	male	10 weeks	voluntary wheel running	chronic social defeat stress	induced ΔFosB in the subregions of the NAc	[66]
3	Sprague–Dawley	female	N/A	voluntary wheel running	uncontrollable tail shock	alleviated behavioural consequences of stress	[70]
4	Fischer F344	male	7–8 weeks	voluntary wheel running	uncontrollable tail shock	attenuated the dorsal raphe nucleus 5-HT activity	[71]
5	Sprague–Dawley	female	4 weeks	voluntary wheel running	food-restriction stress	enhanced the GABAergic inhibition of pyramidal neurons in the dorsal hippocampus	[75]

5-HT—serotonin; NAc—nucleus accumbens; TH—tyrosine hydroxylase; VTA—ventral tegmental area.