Dendritic Spines in Depression: What We Learned from Animal Models

Table 2

The effects of chronic stress on dendritic spines in the prefrontal cortex (PFC).

#	Stress	Paradigms	Animals	PFC	Proteins	References
1	CRS	6 h/day for 21 days	Male SD rats	↓ apical dendrite of layers II and III mPFC		[76]
2	CRS	3 h/day for 21 days	Male SD rats	Apical dendrite atrophy; ↔ basal dendrites in PL mPFC		[89]
3	CRS	6 h/day for 21 days, 21 day recovery	Male SD rats	↓ apical dendrite length, reversible after 21 d in mPFC		[90]
4	CRS	6 h/day for 21 days	Male SD rats	↓ 20% apical dendritic length, ↓ spine density in PL mPFC		[91]
5	CRS	6 h/day for 21 days, 21-day recovery	Male SD rats	↓ 20% apical dendritic arbors in mPFC		[92]
6	CRS	6 h/day for 21 days	Male SD rats	↓ mushroom spine density; ↑ thin spine number in PL mPFC		[93]
7	CRS	1 h/day for 7 days	Male SD rats	↓ spine density in PL mPFC		[94]
8	CRS	6 h/day for 21 days	Male SD rats	↓ apical spine density in apical dendrites; Inhibition of PKC prevents spine loss		[95]
9	CRS	6 h/day for 21 days/with 21-day recovery	Male SD rats	↓ apical dendrite arbors, ↓ spine density; partial recovery of dendrites and spine loss in IL mPFC		[96]
10	CRS	3 h/day for 7 days	Male and female SD rats	↓ apical dendrite arbors in male, ↑ apical dendrite arbors in female, which is estradiol dependent in mPFC		[97]
11	CRS	6 h/day for 21 days	Male SD young and aged rats	↓ apical dendrite arbors in young, but not aged, rats are reversible; ↓ spine density in young, but not aged, rats		[98]
12	CRS	6 h/day for 21 days	Male SD rats young, middle-aged, and aged	↓ spine density (↓ thin and stubby spines, ↔ mushroom spines) in young but not middle-aged and aged rats in PL mPFC		[99]
13	CRS	6 h/day for 21 days	Male SD rats	↑ mRNA levels of VAMP2, VAMP1, syntaxin 1A, synapsin, synaptotagmins I and III, and synapsins I and II; ↓ SNAP-25 mRNA level	↑ protein levels of VAMP2, syntaxin 1A, and SNAP-25	[100]
14	CRS	2 h/day for 7 days	Adult male WT mice	↓ spine density in mPFC; ↓ apical dendrites	↓ BDNF	[101]
15	CRS	1 h/day for 21 days	Male GIN mice	↔ spine density in mPFC	↑ NCAM, SYN	[102]
16	CRS	6 h/day for 21 days	Male SD rats	↓ spine density in PL mPFC	Alpha-2A-adrenoceptor	[103]
17	CRS	3 h/day for 21 days	Male SD rats; PL mPFC	↓ dendritic retraction is prevented by D1R antagonist SCH23390 that causes dendritic retraction in unstressed rats		[104]
18	CRS	2 h/day for 7 days	Male SD rats	↓ glutamatergic transmission in PFC pyramidal neurons		[105]
19	CUMS	15 days or 35 days	Male SD rats	35% ↓ cell proliferation in neocortex		[106]
20	CUMS	3 stressors/day for 21 days	Male Wistar rats	↓ volume of layer I/II of PL and IL; ↓ neuronal density of layer II of PL and IL; Apical dendritic atrophy in PL and IL; ↔ spine density tends to decrease in PL and IL		[107]
21	CUMS	2 stressors/day for 21 days	Male SD rats	↓ spine density in mPFC; ↓ synapsin I, GluR1, and PSD95		[108]
22	CUMS	1 stressors/day for 21 days	Male SD rats	↓ synaptic length of the active zone in CG1 mPFC; ↓ PSD thickness in PL; ↓ PSD93, ↓ PSD95, ↓ spinophilin in CG1 and PL	↓ spinophilin and synapsin 1 in CG1	[52]
23	CIS	2 h/day for 10 days	Male SD rats	↔ apical dendrites in IL-BLA projecting neurons in IL mPFC; Apical dendritic atrophy in random selected neurons in IL mPFC; ↔ spine density in IL mPFC		[109]
24	Depressed patients		Postmortem dorsolateral PFC	↓ synapse number in dorsolateral PFC, ↓ synaptic-function-related genes	GATA1 ↑; Rab4b ↓	[110]
25	CORT, vehicle	daily injection for 21 days	Male SD rats	↑ spine density proximal to the soma		[111]
26	Forced swim	10 min/day for 3 days	Adult male C57BL/6J mice	↓ apical dendrites in IL mPFC; ↔ basal dendrites in IL mPFC; ↔ apical and basal dendrites in PL mPFC		[112]
27	Early-life stress	3 h/day on postnatal days 1–14	Male Wistar rats	↓ spine density in apical and basal dendrites in mPFC	GluR1, GluR2, αCaMKII, and PSD95 ↑	[113]

CRS: chronic restraint stress. CUMS: chronic unpredictable mild stress. CIS: chronic immobilization stress. PL: prelimbic region of the mPFC. IL: infralimbic region of the mPFC. CG1: area 1 of cingulate region of mPFC. CORT: corticosterone. ↔: no change. ↓: decrease. ↑: increase.