Table 2.
Characteristics of EEG and epileptic phenotype in animal models of RTT.
| Study | Genotype (Age) | Electrode Position, Behavioral State | EEG Characteristics | Seizure Characteristics (Prevalence) |
|---|---|---|---|---|
| [113] | Mecp−/+ (from 13 to 104 weeks) | hippocampal CA1 and contralateral somatosensory cortex, free behavior |
cortical discharges, behavioral freezing 13 weeks average number per hour: 20.7 ± 11.7 duration: 0.9 ± 0.28 s 104 weeks average number per hour: 116.8 ± 44.2 duration: 1.7 ± 0.23 s aggravated by levetiracetam reduced by valproic acid and acetazolamide suppressed by ethosuximide |
|
| [116] |
Vglut2-Mecp2flox/y (10 weeks) Vglut2-Mecp2LSL/y (25–30 weeks) |
right frontal cortex and somatosensory cortex left hippocampal CA1 and dentate regions |
Vglut2-Mecp2flox/y (37.5%) cortical spike-and-wave discharges average number per hour: 3.3 ± 2.1 duration: 4.1 ± 0.4 s Vglut2-Mecp2LSL/y (25%) cortical spike-and-wave discharges average number per hour: 3.3 duration: 4.5 ± 0.8 s |
|
| [110] |
PV-Mecp2-/y
SOM-Mecp2-/y |
SOM-Mecp2-/y (50%) epileptic seizures starting at 12 weeks generalized tonic-clonic seizures observed during routine handling PV-Mecp2-/y no seizures |
||
| [111] |
Rosa26-Esr/Cre- Mecp2 Stop/+, (around 36 week) Rosa26-Esr/Cre-Mecp2Stop/y, (5.5–8.5 weeks) |
hippocampal CA1 and contralateral somatosensory cortex, free behavior |
▼ gamma (35–60 Hz) power (Rosa26-Esr/Cre-Mecp2Stop/+; Rosa26-Esr/Cre-Mecp2Stop/y) rescue in Rosa26-Esr/Cre-Mecp2Stop/y ▼ theta frequency rescue in Rosa26-Esr/Cre-Mecp2Stop/y |
Rosa26-Esr/Cre-Mecp2Stop/y cortical discharges average number per hour: 45 ± 8 duration: 2.8 ± 0.7 s frequency: 6.2 ± 0.3 Hz Rosa26-Esr/Cre-Mecp2Stop/y-rescue cortical discharges average number per hour: 21 ± 3 duration: 1.0 ± 0.1 s frequency: 6.8 ± 0.2 Hz Rosa26-Esr/Cre- Mecp2 Stop/+ cortical discharges average number per hour: 76 ± 17 duration: 1.11 ± 0.1 s frequency: 7.9 ± 0.4 Hz Rosa26-Esr/Cre- Mecp2 Stop/ + -rescue cortical discharges average number per hour: 32 ± 4 duration: 1.2 ± 0.1 s frequency: 7.7 ± 0.3 Hz |
| [117] | Mecp2tm1.1Bird (6–7 weeks) | the M1 region of the frontal cortex, free behavior | ▼ delta power during NREM | cortical discharges, behavioral freezing 13 weeks average number per 20.7 ± 11.7 versus 116.8 ± 44.2 104 weeks |
| [98] |
Emx1-Mecp2, Dlx6a-Mecp2 (6–8 weeks) |
frontal and parietal cortex |
Emx1-Mecp2 spike-wave discharges, absence seizures average number per hour: 36 ± 7 duration: 1.3 ± 0.1 s Dlx6a-Mecp2 no discharges |
|
| [109] |
Mecp22lox/y; Dlx5/6-Cre Mecp22lox/y; Emx1-Cre Mecp2Stop/y; Emx1-Cre (8, 7 weeks) Mecp22lox/y; PV-Cre (13 weeks) Mecp22lox/y; SOM-Cre (13 weeks) |
hippocampus |
Mecp22lox/y; Dlx5/6-Cre behavioral seizures following handling spikes and wave discharges, behavioral arrest Mecp22lox/y; Emx1-Cre no behavioral or electrographic seizures Mecp2Stop/y; Emx1-Cre behavioral seizures Mecp22lox/y; PV-Cre no behavioral seizures Mecp22lox/y; SOM-Cre no behavioral seizures |
|
| [118] |
Mecp2−/+, Mecp2−/y, TH-Mecp Stop/+ (around 36 weeks) TH-Mecp2Stop/y (5.5–8.5 weeks) |
hippocampal CA1 and contralateral somatosensory cortex, free behavior |
▼ theta frequency partial preservation in TH-Mecp2Stop/y ▼ gamma (35–60 Hz) power partial preservation in TH-Mecp2Stop/y |
Mecp2−/y (100%) cortical discharges average number per hour: 42.1 ± 7.9 duration: 2.8 ± 0.7 s frequency: 6.2 ± 0.3 Hz TH-Mecp2Stop/y (100%) cortical discharges average number per hour: 20.5 ± 6.3 duration: 2.2 ± 0.6 s frequency: 6.5 ± 0.36 Hz Mecp2-/+ cortical discharges average number per hour: 69.6 ± 15.5 TH-Mecp Stop/+ cortical discharges average number per hour: 67.1 ± 13.9 |
| [29] | Mecp2T158A/y (4.2 weeks and 12.9 weeks), Mecp2−/y (12.9 weeks) | hippocampal electrode, free behavior | ▲ gamma high (70–140 Hz) power seizure behaviors (unspecified) |
|
| [112] | Mecp2−/+ (42–57 weeks) | parietal cortex, free behavior |
▼ the average number of delta cycles over a 24-h period ▼correlation coefficient for delta power and movement |
cortical discharges, behavioral freezing average number per hour: 10.7 ± 1.6 duration: 0.76 ± 0.01 s frequency: 8.6 ± 0.02 Hz |
| [119] |
Viaat-Mecp2−/y (9 weeks) Dlx5/6-Mecp2−/y (39 weeks) |
cortical electrodes, free behavior |
Viaat-Mecp2−/y hyperexcitability discharges, no electrographic seizures Dlx5/6-Mecp2−/y no hyperexcitability discharges |
|
| [107] |
Mecp2−/y (7–10 weeks), Mecp −/+ (35–52 weeks) |
hippocampal CA1 and contralateral somatosensory cortex, free behavior |
▼ theta frequency (hippocampus) desynchronized, low-amplitude cortical activity =cortical delta and hippocampal sharp-wave activity during sleep |
Mecp −/+ (100%) cortical discharges, immobile animal, no myoclonus average number per hour: 9.1 ± 1.3 duration: 1–2 s frequency: 8.8 ± 1.3 Hz suppressed by ethosuximide |
| [106] | Mecp2308/y (age of recording not specified) | frontal and parietal cortex, free behavior | spike-and-wave discharges, behavioral arrest, generalized myoclonic jerks |
Mecp2308/y-expression of truncated protein, PV-Mecp2-/y-deletion of Mecp2 from parvalbumin positive neurons), SOM-Mecp2-/y-deletion of Mecp2 from somatostatin positive neurons), Mecp22lox/y; Dlx5/6-Cre-deletion of Mecp2 from GABAergic neurons in the forebrain, Mecp22lox/y; Emx1-Cre-deletion of Mecp2 from glutamatergic neurons in the forebrain, Mecp2Stop/y; Emx1-Cre-preservation in glutamatergic and glia, Mecp22lox/y; PV-Cre, Mecp22lox/y; SOM-Cre, Vglut2-Mecp2flox/y-Mecp2 deletion from excitatory neurons, Vglut2-Mecp2LSL/y-restoration of expression of Mecp2 only in excitatory neurons, Viaat-Mecp2−/y-deletion of Mecp2 from >90% GABAergic neurons), Dlx5/6-Mecp2−/y-deletion of Mecp2 from GABAergic neurons in the forebrain, Emx1-Mecp2-deletion of Mecp2 from excitatory neurons and glia in forebrain and hippocampus, Dlx6a-Mecp2-deletion of Mecp2 from inhibitory neurons in the forebrain), TH-Mecp Stop/+, TH-Mecp2Stop/y-preservation of Mecp2 expression in catecholaminergic neurons, Mecp2tm1.1Bird-Mecp2 knockout.