Review Article

Adult Hippocampal Neurogenesis in Alzheimer’s Disease: An Overview of Human and Animal Studies with Implications for Therapeutic Perspectives Aimed at Memory Recovery

Table 2

Studies investigating memory in relation to AHN in AD mouse models.

Mouse modelAgeTestBehavioural outcomeIncreased neurogenesis byRef

APP/PS18 monthsMWM↑ escape latency, ↓ time in target quadrant, ↓ platform crossingsb2AR activation (clenbuterol)46
8-9 monthsPA (a)↓ latency and ↑ frequency to enter in dark compartmentosthole (a), (b)51
MWM (b)↑ escape latency, ↑ distance from platform, ↓ platform crossings
6 monthsMWM↑ escape latencyL-3-n-butylphthalide (L-NBP)52
12 monthsMWM (a)↑ escape latency, ↓platform area crossings, ↓ time spent in target quadrantNSC translpant (a), (b)75
SD (b)↓ latencies; ↑ error time
1,3,6,9,12 monthsFC↓ freezing from 6 months of agesocial interaction76
2 monthsEPM (a)= time and number of entries in open armsenriched environment (a)87
FC (b)= time in freezing-
6 monthsNOR (a)↓ recognition indexPDE7 inhibitor (S14) (a), (b)77
MWM (b)↑ escape latency
12 monthsMWM↑ escape latency, ↓ time in target quadrant, ↓ platform area crossingsrunning78
9 monthsMWM↑ escape latency, ↓ platform area crossings, ↓ time in target quadrantosthole81
8 monthsMWM↑ escape latency, ↓ time in target quadrantMDA7 (CB2 receptors agonist)83
4, 7-8 monthsMWM (radial version)↑ error rateFGF2107
18 weeksNOR (a)↓ recognition indexminocycline (a)109
YM (b)= alternation rate
7 monthsMWM (radial version)↑ error rateIL-10113

APP/PS1ΔΕ928 weeks (female)MWM↑ escape latency, ↓ time in platform area, ↓ platform crossingsmetformin44
3 monthsnest building behavior (a)↓ nesting scoreyonkenafil (a, dose-dependent), (b), (c, dose-dependent)57
SA (b)↓ alternation and arm entries
MWM (c)↓ escape latency, ↓ platform crossings
9-18 monthsSA↓ alternation rate at 18 months ageParoxetine72
3 monthsOF (a)= locomotor activityxanthoceraside (b, dose-dependent), (c, dose-dependent)73
YM (b)↓ spontaneous alternation
NOR (c)↓ discrimination index
3, 9 monthsNOR= exploration for novel object at 3 months-80
Locomotor activity↑ activity at 3 months-
YM= time in open arms at 3 months-
MWM↑ escape latency at 9 months-
9 monthsMWM↑ escape latency, ↓ platform area crossings and time in target quadrantosthole82
8-9 months (female)OL↓ exploratory preference for displaced objectenhancing functional integration of new neurons85

APP/PS1 KI6 monthsEPM (a)↑ time in open arms-71
YM (b)↓ alternation rate-
2-6 monthsneurological evaluation (a)↓ of vertical activity (age-related), = other parameters, hyperactivity-79
6 monthsEPM (b)↑ time in open arms-
2, 4, 6 monthsMWM (c)↓ in goal target (age-related), ↓ accuracy (age-related)-

APPSw,Ind4 months (plus 7 weeks EE)MWM↑ escape latency, ↓ time in platform area, ↓platform crossingsEnvironmental Enrichment50

Tg25763,6, 9 monthsFC (contextual and cue)↓ freezing to context after stress (isolation) at 6 and 9 monthsFluoxetine43

3xTgAD6 monthsOL↓ exploratory preference for displaced objectTHIP (Gaboxadol)68
FC (pattern separation)↑ trials for discrimination
3 monthsTEC↓ conditioned responsesAllopregnanolone48

CRND83, 7 monthsSD (a)↓step-down latencyLithium salts (a) 3 months only, (b) 3 months only74
MWM (b)↑ escape latency, ↓ time in target quadrant

ApoE3-Ki and ApoE-4 KI10-17 monthsMWM (a)↓ ApoE4-KI preference for target quadrant (respect to Apoe3-KI)Transplant of embryonic interneuron progenitor (a), (b), (c)119
OF (b)↓ ApoE4-KI time in central area (respect to Apoe3-KI)
EPM (c)↓ ApoE4-KI time in open arms (respect to Apoe3-KI)

Table summarizes studies investigating neurogenesis and memory in distinct AD mouse models (column 1) at different age points (column 2). Column 3 reports the memory test(s) used in each study. Column 4 refers to results from each memory test with symbols indicating increase (↑), decrease (↓), or no variation (=) of specific behavioral outcomes as compared to wild type controls (unless otherwise indicated). Please note (↑) latency corresponds to lower memory. When available, treatments that were associated with a rescue in neurogenesis and also ameliorated memory are reported in column 5. MWM: Morris water maze (standard or radial); PA: passive avoidance; SD: step down; FC: fear conditioning (contextual or cue); EPM: elevated plus maze; NOR: novel object recognition; OF: open field; YM: Y maze; SA: spontaneous alternation; OL: object location; TEC: trace eye-blink conditioning.