Table 1.
Summary of findings on hippocampus and amygdala.
| Article | N | Human/Animal | Sex | Age of adversity | Test during or post adversity | Age at test | Adversity | Findings |
|---|---|---|---|---|---|---|---|---|
| Admon et al. (2009) | 50 | Human adults | 25M/25F | 18 years | Within 6 months post stress | 19 years | Combat exposure | 1. Amygdala Reactivity pre stress predicted increase in stress-related symptomology. |
| 2. Increases in Hippocampal reactivity predicted increases in stress-related symptomology | ||||||||
| Gilbertson et al. (2002) | 35 | Human adult | 12M Combat exposed Twin pairs/23 M noncombat exposed twin pairs | Adulthood | Post | 52.8/51.8 | Combat exposure | 1. Small hippocampal volume is a risk factor for PTSD. No effect of combat stress on volume |
| Kasai et al. (2008) | 41 | Human adult | 18M Combat exposed Twin pairs/23 M noncombat exposed twin pairs | Adulthood | Post | 52.8/51.8 | Combat exposure | 1. Combat exposed twin with PTSD showed decreased hippocampal activity relative to combat exposed twin without PTSD |
| Liberzon et al. (1999) | 39 | Human adult | 14M Combat Exposure and PTSD/11M Combat only/ 14M Control | Adulthood | Post | 45–52 | Combat exposure/current anxiety disorder | 1. PTSD patients exhibited elevated activation of left amygdala to combat sounds for |
| Rauch et al. (2000) | 16 | Human adult | 8M Combat Veterans with PTSD/8 Controls | Adulthood | Post | 48–61 years | Combat exposure/current anxiety disorder | 1. Combat Exposed Veterans with PTSD had exaggerated amygdala responses to faces |
| Shin et al. (2004) | 36 | Human adult | 17 (7M) Combat Exposed Veterans with PTSD/19(9M) Combat Exposed Veterans without PTSD | Adulthood | Post | adulthood | Combat exposure/current anxiety disorder | 1. Male Combat Veterans with PTSD exhibited elevated amygdala activity |
| Shin et al. (2004) | 16 | Human adult | 8M Firefighters with PTSD/8M Controls | Adulthood | Post | adulthood | Fire fighting exposure/current anxiety disorder | 1. Participants with PTSD showed decreased hippocampal activation during memory task. |
| 2. Participants with PTSD had smaller hippocampal volume than controls | ||||||||
| Gianaros et al. (2007) | 48 | Human adults | 48 F | Adulthood | During | 48 years | Self report of stress on perceived stress scale for 20 years | 1. Decreases hippocampal volume associated with increased life stress |
| Armony et al. (2005) | 13 | Human adults | 9F/4M | Adulthood | Post (within past 4–6 weeks) | 19–57 years | Motor vehicle accidents | 1. Increased amygdala activation to masked fearful faces > masked happy faces |
| Andersen et al. (2008) | 43 | Human adults | 26F with abuse; 17F healthy controls | Childhood | Post | 18–22 years | Retrospective sexual abuse reporting | 1. Sexual abuse at 3–5 or 11–13 years of age was associated with reductions in hippocampal volume. 2. Sexual abuse at 9–10 and 14–16 years was not |
| Bremner et al. (1997) | 34 | Human adult | 12M/5F with child abuse; 12M/5F matched controls | Childhood | Post | 30–50 years | Chronic child abuse (at least once a month for a year) | 1. PTSD patients have smaller hippocampus and unchanged amygdala |
| Cohen et al. (2006) | 250 | Human adult | Sex unreported; 100 with 2 or more early negative events/150 with less than 2 negative events | Childhood | Post | 18–70 years; mean age 40 years | Retrospective reporting of early life stressors (various) | 1. Differences in hippocampal volume were marginally significant and amygdala were nonsignificant between groups |
| Driessen et al. (2000) | 42 | Human adults | 21F patients with borderline personality disorder/21 age, gender, handedness matched contents | Childhood | Post | 21–40 years | Childhood trauma/current borderline personality disorder | 1. Patients had 16% smaller hippocampal volume and 8% smaller amygdala than controls |
| Schmahl et al. (2003) | 33 | Human adult | 10F with Borderline Personality Disorder and childhood trauma/10F controls with childhood trauma/13F controls with no trauma | Childhood | Post | 20–39 years | Childhood trauma/Borderline Personality Disorder (BPD) | 1. Patients with BPD had smaller amygdala (∼22%) and hippocampal (∼14%) volumes; Trauma exposure only was not tested |
| Carrion et al. (2001) | 24 | Human children | 14M/10F with trauma and PTSD or subthreshold PTSD; 14M/10 Fage matched controls | Childhood | Post | 7–14 years | Various traumatic exposures | No differences in hippocampal volume |
| DeBellis et al. (1999a) | 52 | Human children | 44 Children with PTSD (25M)/61 Control (36M) | Childhood | Post | 8–13 years | Childhood maltreatment/current anxiety disorder | 1. Decreased intercranial and cerebral volume, increased ventricle size. |
| 2. No differences in hippocampal volume | ||||||||
| DeBellis et al. (2001) | 18 | Human children | 9 Children with PTSD(5M)/9 age, gender, Tanner Stage matched Controls | Childhood/ pre-puberty | Post | Pre (10 years)/post (13 years) puberty; longitudinal design | Childhood maitreatment/current anxiety disorder | 1. No significant decrease in hippocampal volume for children with PTSD across adolescence in a longitudinal design |
| Tottenham et al. (2009b) | 62 | Human children | 8M/26F previously institutionalized; 5M/23F comparison | Infancy | Post | 5–12 years | Adverse caregiving | 1. Larger amygdala volume in previously institutionalized group. |
| 2. No differences in hippocampal volume | ||||||||
| Mehta et al. (2009) | 25 | Human children | 6M/8F previously institutionalized; 6M/5F comparison | Infancy | Post | 16 years | Adverse caregiving | 1. Larger amygdala volume in previously institutionalized group. |
| 2. No differences in hippocampal volume | ||||||||
| Conrad et al. (1999) | 72 | Sprague-Dawley rat | 36M chronically stressed/ 36M no stress | Adulthood | 0, 10, and 20-days post stress termination | Adulthood | 6 h of restraint stress for 21 consecutive days | 1. Decreased hippocampal CA3 apical dendrite morphology. |
| 2. 10 or 20 days of recovery eliminated changes in dendritic morphology caused by stress | ||||||||
| Honkaniemi et al. (1992) | 24 | Sprague-Dawley rat | 20 Capsaicin/4 Control | Adulthood | Post | Adulthood | Capsaicin | 1. Expression of c-fos, c-jun, and junB in the PVN and central nucleus of the amygdala |
| Kim et al. (2001) | 28 | Long-Evans rats | 28M | Adulthood | Post | Adulthood | Restraint/tail shock | 1. Lesioning the amygdala pre-stress protected hippocampal structure (LTP) and function (Morris Water Maze) effects of stress exposure |
| Vyas et al. (2002) | 3 groups | Adult Wistar rats | Male Wistar Rats (Chronic Immobilization Stress/Chronic Variable Stress/Control | 2-months old (adulthood) | Directly after stress | 3-months old (adulthood) | Chronic immobilization stress/chronic variable stress | 1. Accelerated dendritic arborization in the amygdala. |
| 2. Dendritic atrophy in CA3 (hippocampus) | ||||||||
| Vyas et al. (2004) | 3 groups | Adult Wistar rats | Male Wistar Rats (Chronic Immobilization Stress/Chronic Variable Stress/ Control | 2.5–3 months old (adulthood) | Post | 3.5–4 months old (adulthood) | Chronic immobilization stress | 1. Anxiety behavior and amygdala dendtric arborization persisted in stressed rats compared to control. |
| 2. Hippocampal dendritic atrophy did not persist after 21 days of recovery | ||||||||
| Liu et al. (1997) | – | Norway rat | Several large liters | PND 1–10 | Post | Adulthood | Reduced maternal care | 1. Increased adrenocorticotropin and corticosterone to stress, decreased hippocampal GR mRNA |
| Plotsky et al. (2005) | 20 | Long evans hooded rats | 5M non-handled/ 5M handled/5M maternal separation/5 M control | PND2–14 | Post | PND 100–120 | Maternal separation | 1. Elevated CRH mRNA in Amygdala of Maternally separated and non-handled rats |
| Brunson et al. (2005) | Sprague-Dawley rat | Several male litters | PND2-weaning | Post | 4-and 12-months old | Poor maternal care | 1. Impaired hippocampal function appeared only in middle aged adults | |
| Tsoory et al. (2008) | 104 | Sprague-Dawley rat | 56M exposed to juvenile stress/48M control | PND 27–29 | Post | PND 33 - juvenile/9-week-old adult | 3-day variable stress exposure | 1. Increased neural cell adhesion molecule in basolateral amygdala, hippocampus CA1, dentate gyrus, entorhinal cortex measured at adulthood but not during the juvenile period |
| Andersen and Teicher (2004) | 100 | Sprague-Dawley rat | 50M/50F | PND 2–20 | Post | PND 25, 40, 60, 80, 100 | Maternal separation | 1. Synaptophysin OD decreases in hippocampal CA1 and CA3 at postnatal day 60 (not before). |
| 2. No effect on Synaptophysin OD in the amygdala | ||||||||
| Ono et al. (2008) | 148 | Balb/c mice | 76 (33M) early weaned/ 72 (34M) typically weaned | PND 14 | Post | 3, 5, and 8 weeks of age | Early weaning (PND 14) | 1. Precocious development of amygdala, not hippocampus (accumulation of galactosylceramide) at 5 weeks of age |
| Chen et al. (2006) | 55 | Sprague-Dawley rat | 55 stressed | PND 18 and Adult (3 months old) | Directly after stress | PND 18 and Adult | Restraint/restraint-noise | 1. Hippocampal response (FOS) to stress was more rapid and robust at PND 18 than adulthood |
| Kikusui and Mori (2009) | 129 | Balb/c mice | 63(28M) early weaned/66 (32M) typically weaned | PND 14 | Post | 8–22 weeks | Early weaning (PND 14) | 1. Accelerated amygdala development |
| Salzberg et al. (2007) | 29 | Wistar rats | 16 (9M) maternal separation/13 (6 M) early handling | PND 2–14 | Post | 7 weeks | Maternal Separation | 1. Amygdala sensitization following maternal separation |
| Isgor et al. (2004) | 156 | Juvenile Sprague Dawley rats | 156M | PND 28 | 24 h post stress/ 3 weeks post stress | PND 57/77 | 28 days of variable chronic stress | 1. 3 weeks post stress when rodents were adults hippocampal volume (CA1 and CA3) was decreased due to inhibited growth. |
| 2. 24-h post stress when rodents were still juvenile hippocampal volume differences were absent or reversed | ||||||||
| Becker et al. (2007) | 20 | Octodon Degus | 10M stressed/10M non-stressed | PND 1–21 | Post stress | PND 22 (post weaning/pre reproduction) | PND1–21 separated 1x per day for 1 h | 1. Higher levels of CRF neurons in basolateral amygdala. |
| 2. Lower levels of corticotropin releasing factor (CRF) fibers/neurons in central amygdala and hippocampal dentate gyrus and CA1 | ||||||||
| Vazquez et al. (2006) | 300 | Hybrid Sprague-Dawley/Long-Kvans | 80 (40M) stress at PND 6/ 80(40M) stress at PND 12/80(40M) stress at PND 18/ 60(30M) controls | PND 6, 12, or 18 | Directly after, 1 h after, or 4 h after | PND 6, 12, or 18 | Maternal separation and restraint stress | 1. Basal CRH gene expression is higher at earlier ages in amygdala than hippocampus. |
| 2. Deprivation had site-specific effects on the temporal response to restraint stress | ||||||||
| Vazquez et al. (1996) | 12 groups | Juvenile Wistar rats | Stressed at PND 6, 9, or 18/ challenged at PND 6, 9, 18/ control PND 6, 9,18 | PND 6/9/18 | 1-h post stress | PND 6/9/18 | Maternal deprivation/saline injection | 1. Mineral corticoid receptor (MR) and glucocorticoid receptor (GR) mRNA decreases in hippocampus of deprived pups |
| Moriceau et al. (2004) | 108 | Juvenile Long Evans rats | Approximately 1/2 M | PND 8 or 12 | During stress | PND 8 or 12 | Predator odor | 1. Exogenously administered Cortisol increased amygdala activation and fear responding in young rats |
| Hatalski et al. (1998) | 2 litters | Juvenile Sprauge Dawley | Mixed litters | PND 9/10 | 4-h post stress | PND 9/10 | Single exposure to cold stress/3 exposures to cold | 1. Increased CRF-mRNA in the central nucleus of the amygdala |
| Sabatini et al. (2007) | 12 | Juvenile Rhesus Macaque | 4 F 1 week maternally seperated/4F 1 month maternally separated/ 4F controls | Infancy equivalent | Post stress | 3 months | 1 week maternally seperated/1 month maternally separated | 1. Early separation, more than later separation, decreased amygdala gene expression (guanylate cyclase 1 α 3) |
| Spinelli et al. (2009) | 28 | Rhesus monkeys | 15 (7M) mother reared/13 (6M) peer reared | 0–6 months old | Post stress | 23–32 Months (age equivalent to childhood) | Maternal deprivation | 1. No difference in hippocampal volume measurements |